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ISSN: 2052-5206

A variable-temperature study of a phase transition in barbituric acid dihydrate

aSchool of Natural Sciences – Chemistry, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, England
*Correspondence e-mail: w.clegg@ncl.ac.uk

(Received 5 March 2005; accepted 31 May 2005)

The crystal structure of barbituric acid dihydrate (C4H4N2O3·2H2O) has twice been reported as orthorhombic, space group Pnma, with all atoms (except for CH2 H atoms) lying on the mirror plane [Al-Karaghouli et al. (1977[Al-Karaghouli, A. R., Abdul-Wahab, B., Ajaj, E. & Al-Asaff, S. (1977). Acta Cryst. B33, 1655-1660.]). Acta Cryst. B33, 1655–1660; Jeffrey et al. (1961[Jeffrey, G. A., Ghose, S. & Warwicker, J. O. (1961). Acta Cryst. 14, 881-887.]). Acta Cryst. 14, 881–887]. The present study has found that at low temperatures, below 200 K, the crystal structure is no longer orthorhombic but is non-merohedrally twinned monoclinic, space group P21/n. This phase is stable down to 100 K. Above 220 K the crystal structure is orthorhombic, and between 200 and 220 K the structure undergoes a phase change, with the monoclinic-to-orthorhombic phase transition itself taking place at around 216–217 K. The size of the β angle in the monoclinic structure is temperature dependent; at 100 K β is around 94° and it decreases in magnitude towards 90° as the temperature increases. Although the hydrogen-bonding motifs are the same for both crystal systems, there are significant differences in the crystal packing, in particular the out-of-plane displacement of the two water molecules and the sp3-hybridized C atom of barbituric acid.

1. Introduction

Over the past few years, the topic of phase transitions has become more and more popular for scientific investigation. This extremely broad field is actively pursued by physicists, chemists, materials scientists, earth scientists and metallurgists (Pandey, 2005[Pandey, D. (2005). Acta Cryst. A61, 1-2.]). Indeed, the January 2005 edition of Acta Crystallographica Section A: Foundations of Crystallography was devoted almost entirely to the topic. A simple search in February 2005 of SciFinder Scholar 2004 (American Chemical Society, 2004[American Chemical Society (2004). SciFinder Scholar Version 2004.2. http://www.cas.org/SCIFINDER/SCHOLAR/ .]) for `phase transition' resulted in almost 138 500 hits; the top five years according to the greatest numbers of hits were 2003, 2002, 2001, 2000 and 2004. The number of hits in 2003 is 9013, more than double that of 1995 (4457) and a clear indication of the increasing interest in the subject.

[Scheme 1]

Our interest in the temperature-induced phase transition of barbituric acid dihydrate arose from our research on metal complexes of this and related ligands. Barbituric acid is the parent molecule of the barbiturate family of drugs, which are of crystallographic interest not least for their propensity to form polymorphs. The 5,5-dialkyl derivatives are those which are pharmacologically active and which have been most extensively characterized by X-ray crystallography (Caillet & Claverie, 1980[Caillet, J. & Claverie, P. (1980). Acta Cryst. B36, 2642-2645.]; Cleverley & Williams, 1959[Cleverley, B. & Williams, P. P. (1959). Tetrahedron, 7, 277-288.]; Craven et al., 1969[Craven, B. M., Vizzini, E. M. & Rodrigues, M. M. (1969). Acta Cryst. B25, 1978-1993. ], 1982[Craven, B. M., Fox, R. O. & Weber, H.-P. (1982). Acta Cryst. B38, 1942-1952.]; Craven & Vizzini, 1969[Craven, B. M. & Vizzini, E. M. (1969). Acta Cryst. B25, 1993-2009.], 1971[Craven, B. M. & Vizzini, E. M. (1971). Acta Cryst. B27, 1917-1924.]; McMullan et al., 1978[McMullan, R. K., Craven, B. M. & Fox, R. O. (1978). Acta Cryst. B34, 3719-3722.]; Nichol & Clegg, 2005a[Nichol, G. S. & Clegg, W. (2005a). Acta Cryst. C61, o297-o299.],b[Nichol, G. S. & Clegg, W. (2005b). Acta Cryst. E61, o1004-o1006.]; Platteau et al., 2005[Platteau, C., Lefebvre, J., Hemon, S., Baehtz, C., Danede, F. & Prevost, D. (2005). Acta Cryst. B61, 80-88.]; Sambyal et al., 1995[Sambyal, V. S., Goswami, K. N. & Kahjuria, R. K. (1995). Cryst. Res. Technol. 30, 817-823.]; Williams, 1973[Williams, P. P. (1973). Acta Cryst. B29, 1572-1579.], 1974[Williams, P. P. (1974). Acta Cryst. B30, 12-17.]). Contemporary research continues to focus on barbituric acid polymorphism as a model system for developing computational polymorph prediction techniques, something that is of major importance to the pharmaceutical industry (Lewis et al., 2004[Lewis, T. C., Tocher, D. A. & Price, S. L. (2004). Cryst. Growth Des. 4, 979-987.], 2005[Lewis, T. C., Tocher, D. A. & Price, S. L. (2005). Cryst. Growth Des. 5, 983-993.]).

1.1. Analysis of current literature

The structure of barbituric acid dihydrate (I)[link] appears twice in the primary literature: an X-ray diffraction study (Jeffrey et al., 1961[Jeffrey, G. A., Ghose, S. & Warwicker, J. O. (1961). Acta Cryst. 14, 881-887.]) and a neutron diffraction study (Al-Karaghouli et al., 1977[Al-Karaghouli, A. R., Abdul-Wahab, B., Ajaj, E. & Al-Asaff, S. (1977). Acta Cryst. B33, 1655-1660.]). In both reports the data collections were carried out at room temperature, and the crystal system and space group are reported as orthorhombic, Pnma. The final R factors are 0.14 and 0.087, respectively. Both reports conclude that, with the exception of the two H atoms of the CH2 group, all atoms of the barbituric acid and water molecules lie on the mirror plane. During their discussions, both reports make mention of the high atomic displacement observed in the b-axis direction (i.e. perpendicular to the mirror plane). Al-Karaghouli et al. (1977[Al-Karaghouli, A. R., Abdul-Wahab, B., Ajaj, E. & Al-Asaff, S. (1977). Acta Cryst. B33, 1655-1660.]) considered the possibility of an alternative non-centrosymmetric space group, Pn21a (non-standard setting of Pna21), which would allow the atoms to deviate from the (now non-crystallographic) mirror plane. These authors also considered a model in which one of the O atoms was deliberately displaced off the mirror plane and then refined as disordered. Neither of these models gave a satisfactory outcome and they concluded that there was no good reason to doubt the assignment of Pnma as the space group.

2. Experimental

2.1. Preliminary experiments

With these uncertainties in mind, we carried out a low-temperature redetermination of barbituric acid dihydrate for the purpose of having a reference structure of the ligand for reliable comparison with the structures of our metal complexes, also determined routinely at low temperature. It was found that, at 150 K, the crystal system was not ortho­rhombic but non-merohedrally twinned monoclinic and the space group was P21/n. Curious to know whether this result pointed to inaccuracies in the literature reports (which were at least 27 years old), we re-collected data, from the same crystal, at room temperature. As reported by Jeffrey et al. (1961[Jeffrey, G. A., Ghose, S. & Warwicker, J. O. (1961). Acta Cryst. 14, 881-887.]), the crystal decomposed on the diffractometer during data collection from a transparent colourless crystal to a white opaque solid, which did not diffract at all. Nevertheless, sufficient data were collected to confirm that at room temperature the structure is indeed orthorhombic with the space group Pnma. Hence the crystal had undergone a phase transition on warming from low temperature to room temperature (and, presumably, in the reverse direction in the initial flash-cooling). A variable-temperature X-ray diffraction study was carried out to observe the effect of changing temperature on the crystal structure and to determine at what point the phase transition occurs.

2.2. Sample preparation

Crystals of barbituric acid dihydrate were prepared by dissolving a sample of commercially available barbituric acid (obtained as a white powder from Lancaster Synthesis) in distilled water with gentle heating. Storage at 278 K over a weekend resulted in large colourless and perfectly transparent block crystals of barbituric acid dihydrate.

2.3. Experimental strategy

Data were collected on a Bruker SMART 1K CCD diffractometer fitted with an Oxford Cryosystems Cryostream cooler (Cosier & Glazer, 1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]) at 14 different temperatures ranging from 100 to 270 K. Experimental details for selected temperatures are summarized in Table 1[link] (details for all experiments are available in the deposited supplementary material1). A large good-quality crystal, which did not require cutting, was selected from the sample and, on the basis of preliminary experiments, the experimental strategy was started by re-collecting data at 150 K and then proceeding in the following temperature order: 170, 190, 200, 210, 220, 230, 215, 217, 218, 219, 216, 100 and 270 K. A full data collection, as opposed to a simple unit-cell determination, was carried out at each temperature. Such a procedure adds several days to the time taken to conduct the experiments; however, it also allows for complete structure solution and refinement – the ultimate indicator of crystal system correctness and data quality – at each temperature and is especially important when one considers that the crystals were twinned in the monoclinic crystal system; a full data collection allows the determination of unit-cell parameters for both components of the twin from several hundred reflections, rather than the hundred or so that would be measured by only collecting partial data for an orientation matrix. The same data collection strategy (complete sphere of reciprocal space, 0.3° width frames, 30 s exposures) was used for each experiment.

Table 1
Experimental details at selected temperatures

Details for all experiments are given in the deposited CIF.

  100 K 200 K 215 K 217 K 230 K 270 K
Cell setting, space group Monoclinic, P21/n Monoclinic, P21/n Monoclinic, P21/n Orthorhombic, Pmnb Orthorhombic, Pmnb Orthorhombic, Pmnb
a, b, c (Å) 6.0970 (5), 12.7152 (10), 8.8587 (7) 6.1313 (12), 12.703 (2), 8.8456 (17) 6.1580 (9), 12.7515 (18), 8.8763 (13) 6.1770 (18), 12.785 (4), 8.898 (3) 6.1739 (4), 12.7594 (9), 8.8831 (6) 6.2144 (7), 12.7512 (14), 8.8841 (10)
β (°) 94.0510 (14) 92.187 (4) 91.263 (3) 90 90 90
V3) 685.05 (9) 688.5 (2) 696.83 (17) 702.7 (3) 699.77 (8) 703.99 (14)
Dx (Mg m–3) 1.591 1.583 1.564 1.551 1.558 1.549
No. of reflections for cell parameters 3196 4075 3413 4044 4267 3968
θ range (°) 2.3–28.3 2.3–28.2 2.3–28.3 2.3–28.4 2.3–28.3 2.2–28.2
μ (mm–1) 0.15 0.15 0.15 0.14 0.14 0.14
Temperature (K) 100 (1) 200 (1) 215 (1) 217 (1) 230 (1) 270 (1)
Tmin 0.861 0.553 0.331 0.321 0.778 0.797
Tmax 0.978 0.978 0.979 0.979 0.979 0.979
No. of measured, independent and observed reflections 9480, 2263, 2126 7874, 2456, 2397 8726, 2442, 2299 5924, 889, 800 5804, 923, 859 5918, 940, 820
Rint 0.019 0.029 0.026 0.050 0.023 0.023
θmax (°) 28.3 28.3 28.3 28.4 28.3 28.3
Range of h, k, l −7 → h → 7 −7 → h → 7 −8 → h → 8 −8 → h → 7 −8 → h → 8 −8 → h → 8
  −16 → k → 16 −16 → k → 16 −16 → k → 16 −16 → k → 16 −16 → k → 16 −16 → k → 16
  −11 → l → 11 −11 → l → 11 −11 → l → 11 −11 → l → 11 −11 → l → 11 −11 → l → 11
R[F2> 2σ(F2)], wR(F2), S 0.032, 0.085, 1.11 0.087, 0.197, 1.31 0.069, 0.194, 1.19 0.061, 0.154, 1.25 0.043, 0.112, 1.14 0.041, 0.116, 1.11
No. of reflections 2263 2456 2442 889 923 940
No. of parameters 120 120 120 82 82 83
H-atom treatment Mixture of independent and constrained refinement Mixture of independent and constrained refinement Mixture of independent and constrained refinement Only coordinates refined Only coordinates refined Only coordinates refined
Weighting scheme w = 1/[σ2(Fo2) + (0.0407P)2 + 0.142P], where P = (Fo2 + 2Fc2)/3 w = 1/[σ2(Fo2) + (0.0377P)2 + 1.4289P], where P = (Fo2 + 2Fc2)/3 w = 1/[σ2(Fo2) + (0.0892P)2 + 0.5663P], where P = (Fo2 + 2Fc2)/3 w = 1/[σ2(Fo2) + (0.0547P)2 + 0.6287P], where P = (Fo2 + 2Fc2)/3 w = 1/[σ2(Fo2) + (0.0527P)2 + 0.2709P], where P = (Fo2 + 2Fc2)/3 w = 1/[σ2(Fo2) + (0.0639P)2 + 0.1693P], where P = (Fo2 + 2Fc2)/3
(Δ/σ)max 0.009 0.004 0.006 <0.0001 <0.0001 <0.0001
Δρmax, Δρmin (e Å–3) 0.32, −0.30 0.50, −0.58 0.41, −0.43 0.35, −0.28 0.35, −0.20 0.24, −0.29
Extinction method None None None None None SHELXL
Extinction coefficient n/a n/a n/a n/a n/a 0.040 (7)
Experimental parameters common to all data collections: chemical formula: C4H4N2O3·2H2O; Mr = 164.12; Z = 4; radiation type = Mo Kα; crystal form and colour: colourless block; crystal size (mm): 0.53 × 0.42 × 0.15; diffractometer: Bruker SMART 1K CCD; data collection method: thin-slice ω scans; absorption correction: multi-scan (based on symmetry-related measurements); criterion for observed reflections: I > 2σ(I); refinement on: F2. Computer programs used: SMART (Bruker, 2001[Bruker (2001). GEMINI, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), GEMINI (Bruker, 2001[Bruker (2001). GEMINI, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SAINT (Bruker, 2001[Bruker (2001). GEMINI, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXTL (Sheldrick, 2001[Sheldrick, G. M. (2001). SHELXTL. Version 6. Bruker AXS Inc., Madison, Wisconsin, USA.]) and local programs.

The reasons for selecting two extreme temperatures to finish the strategy were to check that the crystal did not undergo a second phase transition at even lower temperatures; so we could verify that the phase transition is reversible; so that we could see that the crystal did not suffer physical stress at extreme cold; and so we could collect data as close to room temperature as possible without the crystal decomposing. The same crystal, pictured in Fig. 1[link], was used for every experiment; the crystal was not removed from the goniometer head between data collections, and a visual examination of the crystal at the end of the experiments showed that it suffered no physical effects (e.g. cracking) as a result of the cooling and heating. Ultimately the same crystal stayed attached to the goniometer head for over 2 weeks.

[Figure 1]
Figure 1
The crystal after two weeks on the diffractometer. The apparent defect at the top right is a ridge in the crystal and not a crack. Other apparent defects on the face of the crystal are air bubbles in the oil used to coat and store the crystal.

The true crystal temperature was verified by collecting data on a crystal of CsOH·H2O (purchased from Lancaster Synthesis). Caesium hydroxide monohydrate is known to undergo a phase transition from C-centred monoclinic to hexagonal at 229 K (Tomaszewski, 1992[Tomaszewski, P. (1992). Phase Transit. 38, 127-220.]). This phase transition was observed at 228–229 K and so the crystal temperature as reported by the Cryostream was found to be reliable. After each temperature change the crystal of barbituric acid dihydrate was allowed to stabilize at the new temperature for around 30 min before starting the data collection.

2.4. Data processing

For each collection the data were processed both as monoclinic and as orthorhombic, regardless of the symmetry implied by the data. This approach proved especially important for those data sets collected around the transition temperature. For example, those data sets which were clearly monoclinic were also processed as orthorhombic, with the β angle constrained in cell refinement after integration and the space group set as Pmnb. We chose this unconventional setting of Pnma so that the unit-cell axes matched those of the monoclinic space group P21/n, thus allowing for detailed comparison of the two structures. Similarly the orthorhombic data sets were integrated as monoclinic with no constraints on the β angle and the space group P21/n selected. By treating each data set in this way and comparing the final monoclinic and orthorhombic refinement results it was, in most cases, obvious which was correct and which was incorrect.

Starting with the 150 K collection the programs GEMINI and SMART (Bruker, 2001[Bruker (2001). GEMINI, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) were used to determine and refine both components of the twin. SAINT (Bruker, 2001[Bruker (2001). GEMINI, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) was then used to integrate the data and TWINABS (Sheldrick, 2002[Sheldrick, G. M. (2002). TWINABS. University of Göttingen, Germany.]) was used to correct for absorption and other effects and to write two corrected data files for structure solution and refinement. The SHELXTL suite of programs was used for space group determination, structure solution and refinement (Sheldrick, 2001[Sheldrick, G. M. (2001). SHELXTL. Version 6. Bruker AXS Inc., Madison, Wisconsin, USA.]). Having refined the structure as non-merohedrally twinned monoclinic to a satisfactory conclusion the data processing was repeated as described above with orthorhombic constraints. We used SADABS (Sheldrick, 2003[Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany.]) and not TWINABS for absorption correction of the (untwinned) orthorhombic data sets. Molecular diagrams and other graphics were produced using DIAMOND (Brandenburg & Putz, 2004[Brandenburg, K & Putz, H. (2004). DIAMOND. Version 3. University of Bonn, Germany.]) and MERCURY (Version 1.3; Bruno et al., 2002[Bruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389-397.]).

This approach was followed for all other data collections, and the non-H atomic coordinates from the 150 K collection were used as starting parameters for structure refinement at all other temperatures. This procedure ensured that factors such as unit-cell origin, atomic coordinates and atomic labels were consistent throughout. Appropriate adjustments were made to the coordinates of the structures in Pmnb to constrain the atoms to lie on the mirror plane in accordance with the space-group symmetry. Anomalies in some of the transmission factor ranges are discussed below.

3. Results and discussion

A summary of the refinement results for each data collection is presented as Table 2[link]. Examination of the results at each temperature shows that it is possible to classify each one as definitely monoclinic, definitely orthorhombic or `transitional', where it is not immediately obvious which is the most appropriate space group, and in some cases both crystal systems seem appropriate. The ADDSYM function of PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]) was very useful in the detection of additional symmetry in the monoclinic structures.

Table 2
Summary of results for refinements at each temperature

    Data to 2θ = 52° Data to 2θ = 50°
Temperature (K) Space group R [Fo2 > 4σ(Fo2)] wR (all F2) R [Fo2 > 4σ(Fo2)] wR (all F2)
100 P21/n 0.0319 0.0827 0.0291 0.0927
150 P21/n 0.0505 0.1309 0.0384 0.1098
170 P21/n 0.0397 0.1027 0.0341 0.1000
190 P21/n 0.0374 0.1004 0.0343 0.1124
200 P21/n 0.0869 0.1967 0.0618 0.1540
210 P21/n 0.0664 0.1496 0.0462 0.1176
215 P21/n 0.0690 0.1919 0.0522 0.1591
216 P21/n 0.0684 0.1806 0.0508 0.1477
217 Pmnb 0.0611 0.1504 0.0469 0.1277
218 Pmnb 0.0539 0.1337 0.0425 0.1156
219 Pmnb 0.0664 0.1597 0.0479 0.1264
220 Pmnb 0.0453 0.1198 0.0391 0.1083
230 Pmnb 0.0429 0.1095 0.0332 0.0914
270 Pmnb 0.0415 0.1239 0.0323 0.0886

3.1. Diffraction patterns

Examination of the diffraction pattern is the most reliable way of determining the correct crystal system of a structure. As a simple example, Fig. 2[link] shows three screenshots of a frame recorded at 100, 215 and 230 K with the crystal in the same orientation. On each frame two pairs of reflections have been highlighted. They share common h and k indices but differ in the value of l (as indicated on the 230 K frame). One reflection of each pair belongs to one component of the twin and the other reflection belongs to the second component of the twin. The two components are related by a 180° rotation about the c axis. At 100 K, a monoclinic temperature, the reflections are well separated and the program GEMINI could easily index both twin components. As the temperature increases the reflections begin to move closer together and at 215 K, a transitional temperature, they are starting to merge. Indexing the diffraction pattern is now not so easy, and both monoclinic and orthorhombic unit cells can be determined. At 230 K pairs of reflections have merged completely, to give discrete reflections with unique indices, and the structure is now ortho­rhombic.

[Figure 2]
Figure 2
Three frames from data collections at 100 K (top), 215 K (centre) and 230 K (bottom).

3.2. Unit-cell parameters

Table 3[link] gives unit-cell parameters for all experiments. Phase transitions are often accompanied by a significant change in unit-cell dimensions, such as the doubling of an axis. Here there is little change in the size of the unit cell save for a gradual increase in unit-cell volume so that the unit cell at 270 K is around 19 Å3 larger than that at 100 K. This difference is largely insignificant, given that unit cells measured at or near room temperature are generally larger than those measured at low temperatures.

Table 3
Unit-cell parameters for all data collections

Temperature (K) a b c α β γ Volume
100 6.0970 (5) 12.7152 (1) 8.8587 (7) 90 94.051 (1) 90 685.05 (9)
150 6.1130 (8) 12.7149 (2) 8.8564 (1) 90 93.437 (2) 90 687.14 (2)
170 6.1270 (5) 12.7253 (1) 8.8633 (8) 90 93.068 (2) 90 690.06 (1)
190 6.1377 (5) 12.7306 (1) 8.8641 (8) 90 92.528 (2) 90 691.94 (1)
200 6.1313 (1) 12.7032 (2) 8.8456 (2) 90 92.187 (4) 90 688.45 (2)
210 6.1538 (2) 12.7474 (3) 8.8776 (2) 90 91.627 (4) 90 696.05 (3)
215 6.1580 (9) 12.7515 (2) 8.8963 (1) 90 91.263 (3) 90 698.40 (2)
216 6.1567 (2) 12.7329 (3) 8.8646 (2) 90 91.180 (5) 90 694.77 (3)
217 6.1770 (2) 12.7851 (2) 8.8984 (3) 90 90 90 702.70 (3)
218 6.1626 (2) 12.7574 (4) 8.8763 (1) 90 90 90 697.80 (4)
219 6.1624 (2) 12.7569 (3) 8.8782 (2) 90 90 90 697.94 (3)
220 6.1665 (1) 12.7626 (4) 8.8814 (2) 90 90 90 698.99 (2)
230 6.1739 (4) 12.7594 (9) 8.8831 (6) 90 90 90 699.77 (8)
270 6.2144 (7) 12.7512 (1) 8.8841 (1) 90 90 90 703.99 (1)

3.3. Orthorhombic structures

Data collected at 220, 230 and 270 K are classed as definitely orthorhombic. At these temperatures GEMINI was unable to determine two separate twin components from the diffraction patterns so the possibility that the data were non-merohedrally twinned was discarded. Orthorhombic and pseudo-orthorhombic models both gave similar satisfactory values of R when refinement had converged, so we examined the pseudo-orthorhombic models for additional symmetry. The use of ROTAX (Cooper et al., 2002[Cooper, R. I., Gould, R. O., Parsons, S. & Watkin, D. J. (2002). J. Appl. Cryst. 35, 168-174.]) showed that 180° rotations were possible about the [100], [010] and [001] reciprocal and direct lattice directions, and analysis with ADDSYM showed an additional mirror plane missing from the model. It was simple to conclude that, at these temperatures, the structures are indeed, as has twice been reported, best described in the higher-symmetry space group Pmnb (or Pnma) rather than in P21/n.

Taking the structure at 230 K as an example, a displacement ellipsoid plot and a packing diagram viewed along the c axis of (I) are given in Fig. 3[link]. H atoms were all located in a difference map and refined with Uiso = 1.2Ueq(C,N,O); their coordinates were refined freely. All atoms, with the exception of the CH2 H atoms, lie on the mirror plane (one of the H atoms in the ellipsoid plot is symmetry generated); this fact is neatly shown by the packing diagram. The two water molecules are coplanar with the barbituric acid ring. Molecular dimensions are unexceptional and in agreement with those reported by Al-Karaghouli et al. (1977[Al-Karaghouli, A. R., Abdul-Wahab, B., Ajaj, E. & Al-Asaff, S. (1977). Acta Cryst. B33, 1655-1660.]), with the exception of the X—H bonds, which are around 0.1–0.2 Å shorter than the previously reported values. This difference is to be expected, since ours is an X-ray diffraction study and we are comparing it with neutron diffraction results.

[Figure 3]
Figure 3
Displacement ellipsoid plot (50% probability) and packing diagram along the c axis of the 230 K structure. Hydrogen bonds are indicated in orange.

3.4. Monoclinic structures

Those structures determined at 100, 150, 170 and 190 K are classed as definitely monoclinic with space group P21/n. In each case the diffraction pattern is non-merohedrally twinned. That the diffraction pattern is twinned as a result of the orthorhombic-to-monoclinic transition is not surprising and is quite common in situations of a material changing from higher to lower symmetry. The two components of the twin are related by a 180° rotation about the c axis, and at low temperatures the extent of the twinning is such that one can clearly see the reflections from both components in the diffraction pattern, as shown in Fig. 2[link]. Attempts to refine these data with orthorhombic models result in refinements with very large R factors. Another curious feature is the change in the magnitude of the β angle with temperature; as shown in Table 3[link], the β angle approaches 90° as the temperature increases towards the phase transition. All of these structures share another common feature in that the barbituric acid molecule is no longer planar. In this space group there is no imposed mirror symmetry and as a result the Csp3 (C4) atom, with its tetrahedral rather than trigonal geometry, is seen to deviate from the mean plane of the rest of the molecule.

Fig. 4[link] shows a displacement ellipsoid plot of (I) at 100 K. All H atoms were identified in a difference electron density map and their coordinates were refined, with the exception of the CH2 H atoms, which were positioned geometrically (C—H = 0.99 Å) and constrained as riding during refinement. All H atoms were refined with Uiso = 1.2Ueq(O,N,C). Molecular dimensions, listed in Table 4[link], are unexceptional and, with the exception of the torsion angles, are more or less the same as those determined at 230 K. Fig. 5[link] shows an overlay of the monoclinic structure at 100 K (red) and the orthorhombic structure at 230 K (black), produced by plotting the mean plane (r.m.s. deviation 0.0288 Å) of atoms C1, O1, N1, C2, O2, C2, N2, C3 and O3 of the monoclinic 100 K structure against the planar ring of the orthorhombic 230 K structure. The out-of-plane displacement of the C4 atom can be clearly seen. This is not an unprecedented observation; the structure of unsolvated barbituric acid shows a similar puckering in the ring (Bolton, 1963[Bolton, W. (1963). Acta Cryst. 16, 166-173.]; Lewis et al., 2004[Lewis, T. C., Tocher, D. A. & Price, S. L. (2004). Cryst. Growth Des. 4, 979-987.]). By using the CALCALL function of PLATON we determined the Cremer–Pople ring puckering parameter Q at 100 K to be 0.0787 Å. This is a very small value but does indicate that at 100 K the ring is distorted to a measurable degree in the envelope conformation. At higher temperatures the ring puckering is less significant and CALCALL does not report it. This small, but significant, conformational flexibility of the barbituric acid molecule has proved to be a major obstacle in polymorph prediction (Lewis et al., 2004[Lewis, T. C., Tocher, D. A. & Price, S. L. (2004). Cryst. Growth Des. 4, 979-987.]).

Table 4
Selected geometric parameters (Å, °) from the monoclinic 100 K structure

Atom sites Bond lengths Atom sites Bond angles Atom sites Torsion angles
N1—C1 1.3643 (13) O1—C1—C4 121.62 (9) C2—N1—C1—C4 −4.70 (16)
N1—C2 1.3810 (13) N1—C1—C4 117.59 (9) C2—N2—C3—C4 6.22 (17)
N2—C2 1.3728 (13) O3—C3—C4 123.01 (9) O1—C1—C4—C3 −172.47 (10)
N2—C3 1.3670 (13) N2—C3—C4 117.29 (9) N1—C1—C4—C3 9.09 (15)
C1—C4 1.5034 (14) C1—C4—C3 115.90 (8) O3—C3—C4—C1 171.19 (11)
C3—C4 1.5054 (14)     N2—C3—C4—C1 −9.76 (15)
[Figure 4]
Figure 4
Displacement ellipsoid plot (50% probability) of the 100 K structure.
[Figure 5]
Figure 5
Overlay of the 100 K structure (red) and 230 K structure (black) showing the out-of-plane displacement of the C4 atom and the two water molecules.

In addition to the ring puckering, the two water molecules are no longer coplanar with the barbituric acid ring. This is a more significant change from the orthorhombic structure and, as a consequence, the molecular packing shows some obvious differences. Fig. 6[link] shows a packing diagram of the structure at 100 K, viewed along the c axis. The hydrogen-bonding motifs in both the orthorhombic and the monoclinic structures are identical but here, because the water molecules are no longer coplanar with the barbituric acid molecules, some adjustment in the packing is necessary to preserve the hydrogen-bonding arrangement. Thus, instead of observing perfectly planar sheets of hydrogen-bonded water and barbituric acid mole­cules, we see sheets that are now rippled in appearance. Hydrogen-bonding parameters are given in Table 5[link].

Table 5
Hydrogen-bonding geometry in the monoclinic 100 K structure

  D—H H⋯A D⋯A D—H⋯A
O4—H1O⋯O2i 0.819 (17) 1.969 (17) 2.7583 (11) 161.9 (16)
O4—H2O⋯O1ii 0.822 (17) 2.034 (17) 2.8508 (11) 172.4 (15)
O5—H3O⋯O4 0.821 (18) 1.931 (19) 2.7463 (12) 171.7 (17)
O5—H4O⋯O1 0.828 (17) 1.967 (18) 2.7819 (12) 167.9 (16)
N1—H1N⋯O3iii 0.823 (15) 1.986 (16) 2.8084 (12) 177.2 (14)
N2—H2N⋯O5iv 0.874 (15) 1.861 (15) 2.7277 (12) 171.2 (14)
Symmetry codes: (i) [1\over 2]x, [1\over 2] + y, [3\over 2]z; (ii) [1\over 2]x, [1\over 2] + y, [1\over 2]z; (iii) [1\over 2]x, −[1\over 2] + y, [3\over 2]z; (iv) x, y, 1 + z.
[Figure 6]
Figure 6
Packing diagram along the c axis of the 100 K structure. Hydrogen bonds are marked in orange.

3.5. Transitional structures

The structures refined from data collected between 200 and 219 K are classed as `transitional'; that is to say, aspects of the data and the refinement imply that the structure is undergoing change of some sort. Table 6[link] gives details of the final refinement outcomes for both space groups and shows also the unconstrained β angle as determined in the monoclinic models. At these temperatures the choice of monoclinic versus orthorhombic was not immediately obvious, and several different approaches to each data set were tried in order to determine which cell setting and space group best described the data.

Table 6
Comparison of refinement details for transitional structures

Temperature β angle R for 2θ < 52° R for 2θ < 50° Mirror plane detected by
(K) (unconstrained) P21/n Pnmb P21/n Pnmb ADDSYM (in P21/n?
200 92.187 (4) 0.0869 0.1020 0.0618 0.0669 No
210 91.627 (4) 0.0664 0.093 0.0462 0.0789 No
215 91.263 (3) 0.0690 0.0865 0.0522 0.0632 No
216 91.180 (5) 0.0684 0.0743 0.0508 0.0546 No
217 90.952 (4) 0.0741 0.0611 0.0596 0.0469 Yes
218 90.139 (4) 0.0670 0.0539 0.0500 0.0425 Yes
219 90.071 (3) 0.0764 0.0664 0.0571 0.0479 Yes
220 90.149 (3) 0.0493 0.0453 0.0428 0.0391 Yes

As can be seen from the refinement results presented in Tables 2[link] and 6[link], data quality at these temperatures was much poorer than those at lower or higher temperatures. In particular, the data above 2θ = 50° were much weaker than previously observed, and removal of these data from the refinement led to a marked improvement in the quality of R and wR. High-angle data quality usually depends on factors such as crystal size and quality, scattering power of the atoms, disorder within the structure, and temperature of data collection. In this study the same crystal was used throughout and the structure is rigid with little scope for disorder, leaving just the effect of increasing temperature as a possible cause of weaker high-angle data. It is true that the lower the crystal temperature, the higher the diffracted X-ray intensities are, and so the more distinguishable from the background are the reflections. However, this fact would not account for such a marked decrease in the data quality from 190 to 200 K. Usually in such a case one would be justified in omitting these poor data from the least-squares calculations. However, this approach would not be appropriate in this case. That the high-angle data at transitional temperatures are poor in comparison to other collections is a significant observation in this study, and it is for this reason that the resolution of the refinement and structure reporting were not restricted to 2θmax = 50°.

Another significant observation is the difference between the minimum and maximum transmission factors resulting from the TWINABS/SADABS scaling, as presented in Table 1[link]. The differences between Tmin and Tmax at 100, 230 and 270 K are reasonable; however, those reported at 200, 215 and 217 K are not. TWINABS and SADABS correct for absorption by comparing the intensities of supposedly equivalent (by symmetry) or repeated (as a result of collecting redundant data) reflections. Given that the same crystal was used for all experiments, the large range of transmission at these intermediate temperatures cannot be connected to the shape or size of the crystal. Each data set was collected using an identical strategy, ruling out the possibility of variation due to changes in experimental settings. The wide variations in the putative absorption corrections must be a partial compensation for the poor quality of data from an intermediate structural state by the frame-scaling procedure in these multi-scan correction methods. We do not believe the variations are due to any hysteresis effect of structural change lagging behind temperature change, since the phase transition is not a large one, and the crystal was held at each new temperature for at least 30 min before data collection began. However, it should be noted that the temperature interval between these data sets is of the same order as the uncertainty in the temperature itself. If the phase transition is one that takes place gradually over a range of several degrees in temperature then some minor variation in the structure, and hence in the diffraction pattern, during each data collection is likely. These intermediate structures should each be regarded as an average structure over a small temperature range, and the range of transmission factors probably reflects this, together with the generally poorer refinement results compared with those at higher and lower temperatures where a single phase is present.

3.5.1. Structures at 200, 210, 215 and 216 K

After much experimentation, several unit-cell determinations, the creation of many different models and seemingly endless refinement cycles, it was concluded that, at these temperatures, the crystal structures are better described as monoclinic rather than orthorhombic. However, in each case the decision was very close and, if taken based on refinement alone, would have been difficult to determine. To verify that orthorhombic was not a more appropriate description of the data, ADDSYM was used to detect missed symmetry and in each case none was detected. The data collected at 215 and 216 K are of particular interest. Examination of the diffraction pattern at 215 K showed pairs of reflections and, although the separation of the reflections was quite small, they are an indicator of twinning. However, at 216 K there are virtually no pairs of reflections; instead they are seen merged and take the form of smeared ellipses rather than separate discrete isotropic spots. Refinement of the orthorhombic model gave a similar result to that of the monoclinic model, and it is possible that there was a combination of both monoclinic and orthorhombic unit cells coexisting in equilibrium at the same time.

3.5.2. Structures at 217, 218 and 219 K

At these temperatures the balance begins to tip towards the ortho­rhombic crystal system. The first major observation at 217 K is that the non-merohedrally twinned crystal system is no longer an appropriate model for the data. Although GEMINI was able to determine two orientation matrices, refinement of the structure was poor, giving very high values of R and wR (0.133 and 0.278, respectively). The refined twin fraction had a very high uncertainty, thus making the parameter (and therefore the twinning) meaningless. As a result the non-merohedrally twinned monoclinic model was quickly discarded. A pure (i.e. untwinned) monoclinic model was tried, giving a slightly better result; however, both ADDSYM and ROTAX suggested that this model was no longer appropriate. Although the unconstrained β angle is still almost a degree away from 90°, at 217 K the orthorhombic model gives the most satisfactory refinement result and we can say that the orthorhombic model is, on balance, the better way to describe the data. At 218 and 219 K the refinement results for the orthorhombic system become increasingly more favourable, and we now are more-or-less able to disregard the monoclinic crystal system as a reliable way of describing the structure; rather than being merely `better described' as orthorhombic they are now clearly orthorhombic – a subtle but important difference.

4. Conclusions

The two previously reported crystal structures of barbituric acid dihydrate in space group Pnma only hold true at temperatures above 220 K. Below 200 K the crystal structure is better described as non-merohedrally twinned monoclinic in space group P21/n, and between 200 and 220 K the crystal structure undergoes a phase transition from monoclinic to orthorhombic. The phase transition is not particularly sharp; whilst the point at which the majority of the diffraction pattern changes from monoclinic to orthorhombic is probably around 216–217 K, the full transition appears to take place over a rather wider temperature range. The transition is reversible and the crystal suffers no physical effects as a result of either the temperatures used or the transition itself.

In the monoclinic structure the magnitude of the β angle is seen to vary with temperature. The angle approaches 90° as the temperature approaches the phase transition. There are no other significant changes in unit-cell dimensions and the observed increase in unit-cell volume is insignificant.

The structural differences in changing from the ortho­rhombic to monoclinic phase are most clearly seen by looking at the displacement of the Csp3 atom of the barbituric acid ring and the significant movement of the two water molecules away from coplanarity with the barbituric acid, as presented in Fig. 5[link]. The orthorhombic phase features all atoms (with the exception of the CH2 H atoms) lying on the mirror plane imposed by the space group, although in the monoclinic phase this is no longer a symmetry requirement and the molecules have the freedom to distort and shift. The hydrogen-bonding motif of both the orthorhombic and monoclinic phases is the same; however, the physical arrangement of the molecules is different, and this difference is best seen by viewing and comparing c-axis projections of the orthorhombic and monoclinic phases.

Supporting information


Computing details top

For all compounds, data collection: Bruker SMART; cell refinement: Bruker SAINT; data reduction: Bruker SAINT. Program(s) used to solve structure: using coordinates of another structure for 100, 190, 200, 210, 215, 216, 217, 218, 220, 230; Bruker SHELXTL for 150; SHELXS97 (Sheldrick, 1990) for 170; by using coordinates of another structure for 219; using coordinates of 150K structure for 270. Program(s) used to refine structure: Bruker SHELXTL for 100, 150, 190, 200, 210, 215, 216, 217, 218, 219, 220, 230, 270; SHELXL97 (Sheldrick, 1997) for 170. For all compounds, molecular graphics: Bruker SHELXTL; software used to prepare material for publication: Bruker SHELXTL and local programs.

Figures top
[Figure 1]
[Figure 2]
[Figure 3]
[Figure 4]
[Figure 5]
[Figure 6]
(100) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.591 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3196 reflections
a = 6.0970 (5) Åθ = 2.3–28.3°
b = 12.7152 (10) ŵ = 0.15 mm1
c = 8.8587 (7) ÅT = 100 K
β = 94.0510 (14)°Block, colourless
V = 685.05 (9) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2263 independent reflections
Radiation source: sealed tube2126 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.019
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; (Sheldrick, 2002)
h = 77
Tmin = 0.861, Tmax = 0.978k = 1616
9480 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.032Hydrogen site location: mixed
wR(F2) = 0.085H atoms treated by a mixture of independent and constrained refinement
S = 1.11 w = 1/[σ2(Fo2) + (0.0407P)2 + 0.142P]
where P = (Fo2 + 2Fc2)/3
2263 reflections(Δ/σ)max = 0.009
120 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C4H4N2O3·2H2OV = 685.05 (9) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.0970 (5) ŵ = 0.15 mm1
b = 12.7152 (10) ÅT = 100 K
c = 8.8587 (7) Å0.53 × 0.42 × 0.15 mm
β = 94.0510 (14)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2263 independent reflections
Absorption correction: multi-scan
TWINABS; (Sheldrick, 2002)
2126 reflections with I > 2σ(I)
Tmin = 0.861, Tmax = 0.978Rint = 0.019
9480 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0320 restraints
wR(F2) = 0.085H atoms treated by a mixture of independent and constrained refinement
S = 1.11Δρmax = 0.32 e Å3
2263 reflectionsΔρmin = 0.30 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.24519 (15)0.55163 (6)0.47580 (8)0.01876 (19)
O20.23088 (14)0.44143 (6)0.95897 (8)0.01791 (19)
O30.30272 (16)0.79018 (6)0.88813 (9)0.0201 (2)
O40.22481 (16)0.88638 (6)0.23924 (9)0.0205 (2)
H1O0.243 (3)0.9158 (13)0.3213 (18)0.025*
H2O0.236 (3)0.9297 (13)0.1714 (18)0.025*
O50.28797 (17)0.67316 (7)0.21840 (9)0.0219 (2)
H3O0.258 (3)0.7355 (15)0.2292 (17)0.026*
H4O0.269 (3)0.6452 (13)0.3010 (19)0.026*
N10.23187 (17)0.49826 (7)0.71716 (9)0.0134 (2)
H1N0.225 (2)0.4367 (12)0.6887 (15)0.016*
N20.25606 (16)0.61721 (7)0.92041 (10)0.01297 (19)
H2N0.259 (2)0.6290 (12)1.0177 (17)0.016*
C10.24285 (17)0.57458 (8)0.60971 (11)0.0126 (2)
C20.23845 (18)0.51492 (8)0.87146 (11)0.0122 (2)
C30.27180 (18)0.70381 (8)0.83037 (12)0.0132 (2)
C40.24598 (19)0.68713 (8)0.66181 (11)0.0131 (2)
H4A0.10730.72100.62250.016*
H4B0.36810.72370.61570.016*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0319 (5)0.0137 (4)0.0107 (4)0.0011 (3)0.0018 (3)0.0003 (3)
O20.0302 (5)0.0112 (4)0.0124 (4)0.0004 (3)0.0017 (3)0.0021 (3)
O30.0357 (5)0.0098 (4)0.0142 (4)0.0016 (3)0.0022 (3)0.0009 (3)
O40.0363 (5)0.0133 (4)0.0117 (4)0.0020 (4)0.0014 (3)0.0006 (3)
O50.0416 (5)0.0137 (4)0.0109 (4)0.0002 (4)0.0055 (4)0.0005 (3)
N10.0213 (5)0.0075 (4)0.0114 (4)0.0002 (3)0.0006 (3)0.0009 (3)
N20.0201 (5)0.0099 (4)0.0090 (4)0.0002 (3)0.0015 (3)0.0008 (3)
C10.0143 (5)0.0114 (5)0.0120 (5)0.0009 (4)0.0005 (4)0.0003 (3)
C20.0140 (5)0.0110 (5)0.0116 (4)0.0001 (4)0.0007 (4)0.0005 (3)
C30.0158 (5)0.0104 (4)0.0134 (5)0.0014 (4)0.0003 (4)0.0006 (3)
C40.0198 (5)0.0087 (4)0.0106 (5)0.0000 (4)0.0002 (4)0.0018 (3)
Geometric parameters (Å, º) top
O1—C11.2227 (13)N1—C21.3810 (13)
O2—C21.2172 (13)N2—H2N0.874 (15)
O3—C31.2205 (13)N2—C21.3728 (13)
O4—H1O0.819 (17)N2—C31.3670 (13)
O4—H2O0.822 (17)C1—C41.5034 (14)
O5—H3O0.821 (18)C3—C41.5054 (14)
O5—H4O0.828 (17)C4—H4A0.9900
N1—H1N0.823 (15)C4—H4B0.9900
N1—C11.3643 (13)
H1O—O4—H2O109.3 (16)O2—C2—N2122.13 (9)
H3O—O5—H4O105.4 (15)N1—C2—N2117.01 (9)
H1N—N1—C1117.9 (9)O3—C3—N2119.69 (10)
H1N—N1—C2116.5 (9)O3—C3—C4123.01 (9)
C1—N1—C2125.59 (9)N2—C3—C4117.29 (9)
H2N—N2—C2118.0 (10)C1—C4—C3115.90 (8)
H2N—N2—C3116.1 (10)C1—C4—H4A108.3
C2—N2—C3125.87 (9)C1—C4—H4B108.3
O1—C1—N1120.77 (9)C3—C4—H4A108.3
O1—C1—C4121.62 (9)C3—C4—H4B108.3
N1—C1—C4117.59 (9)H4A—C4—H4B107.4
O2—C2—N1120.85 (9)
C2—N1—C1—O1176.84 (11)C2—N2—C3—O3174.70 (11)
C2—N1—C1—C44.70 (16)C2—N2—C3—C46.22 (17)
C3—N2—C2—O2178.03 (11)O1—C1—C4—C3172.47 (10)
C3—N2—C2—N11.30 (17)N1—C1—C4—C39.09 (15)
C1—N1—C2—O2178.88 (10)O3—C3—C4—C1171.19 (11)
C1—N1—C2—N20.47 (17)N2—C3—C4—C19.76 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.819 (17)1.969 (17)2.7583 (11)161.9 (16)
O4—H2O···O1ii0.822 (17)2.034 (17)2.8508 (11)172.4 (15)
O5—H3O···O40.821 (18)1.931 (19)2.7463 (12)171.7 (17)
O5—H4O···O10.828 (17)1.967 (18)2.7819 (12)167.9 (16)
N1—H1N···O3iii0.823 (15)1.986 (16)2.8084 (12)177.2 (14)
N2—H2N···O5iv0.874 (15)1.861 (15)2.7277 (12)171.2 (14)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(150) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.586 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 4632 reflections
a = 6.1130 (8) Åθ = 2.3–28.2°
b = 12.7149 (16) ŵ = 0.15 mm1
c = 8.8564 (11) ÅT = 150 K
β = 93.437 (2)°Block, colourless
V = 687.14 (15) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2212 independent reflections
Radiation source: sealed tube2148 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 77
Tmin = 0.861, Tmax = 0.978k = 1616
8078 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.051Hydrogen site location: mixed
wR(F2) = 0.132H atoms treated by a mixture of independent and constrained refinement
S = 1.26 w = 1/[σ2(Fo2) + (0.0334P)2 + 0.5782P]
where P = (Fo2 + 2Fc2)/3
2212 reflections(Δ/σ)max = 0.009
120 parametersΔρmax = 0.38 e Å3
0 restraintsΔρmin = 0.34 e Å3
Crystal data top
C4H4N2O3·2H2OV = 687.14 (15) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1130 (8) ŵ = 0.15 mm1
b = 12.7149 (16) ÅT = 150 K
c = 8.8564 (11) Å0.53 × 0.42 × 0.15 mm
β = 93.437 (2)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2212 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2148 reflections with I > 2σ(I)
Tmin = 0.861, Tmax = 0.978Rint = 0.029
8078 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0510 restraints
wR(F2) = 0.132H atoms treated by a mixture of independent and constrained refinement
S = 1.26Δρmax = 0.38 e Å3
2212 reflectionsΔρmin = 0.34 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2458 (3)0.55201 (11)0.47617 (15)0.0247 (4)
O20.2348 (3)0.44163 (11)0.95867 (15)0.0236 (4)
O30.2937 (3)0.79015 (11)0.88781 (17)0.0285 (4)
O40.2305 (4)0.88662 (12)0.23946 (18)0.0278 (4)
H1O0.250 (5)0.916 (2)0.320 (3)0.033*
H2O0.238 (5)0.929 (2)0.170 (3)0.033*
O50.2812 (4)0.67297 (13)0.21710 (18)0.0310 (4)
H3O0.256 (6)0.733 (3)0.227 (3)0.037*
H4O0.266 (5)0.648 (2)0.300 (4)0.037*
N10.2353 (3)0.49880 (13)0.71740 (18)0.0167 (4)
H1N0.234 (5)0.437 (2)0.690 (3)0.020*
N20.2549 (3)0.61716 (12)0.92001 (18)0.0161 (4)
H2N0.260 (5)0.6291 (19)1.014 (3)0.019*
C10.2440 (4)0.57482 (15)0.6094 (2)0.0157 (4)
C20.2408 (4)0.51528 (14)0.8709 (2)0.0157 (4)
C30.2682 (4)0.70428 (15)0.8303 (2)0.0167 (4)
C40.2468 (4)0.68739 (14)0.6622 (2)0.0166 (4)
H4A0.37000.72380.61670.020*
H4B0.10970.72150.62230.020*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0445 (11)0.0176 (7)0.0121 (6)0.0012 (8)0.0034 (7)0.0008 (5)
O20.0422 (10)0.0136 (7)0.0151 (7)0.0007 (7)0.0020 (7)0.0032 (5)
O30.0556 (12)0.0113 (7)0.0181 (7)0.0019 (8)0.0027 (8)0.0009 (5)
O40.0529 (12)0.0151 (7)0.0153 (7)0.0038 (8)0.0023 (8)0.0017 (6)
O50.0626 (13)0.0177 (7)0.0133 (7)0.0002 (9)0.0072 (8)0.0008 (6)
N10.0279 (10)0.0066 (7)0.0156 (8)0.0008 (7)0.0001 (7)0.0007 (6)
N20.0265 (10)0.0122 (7)0.0097 (7)0.0006 (7)0.0018 (7)0.0015 (6)
C10.0199 (11)0.0123 (8)0.0151 (9)0.0022 (8)0.0019 (8)0.0006 (7)
C20.0202 (11)0.0121 (8)0.0147 (9)0.0012 (8)0.0005 (8)0.0010 (7)
C30.0208 (12)0.0113 (8)0.0179 (9)0.0006 (8)0.0001 (8)0.0009 (7)
C40.0272 (12)0.0091 (8)0.0133 (9)0.0003 (8)0.0004 (8)0.0021 (6)
Geometric parameters (Å, º) top
O1—C11.216 (2)N1—C21.374 (2)
O2—C21.219 (2)N2—H2N0.85 (3)
O3—C31.211 (2)N2—C21.367 (2)
O4—H1O0.81 (3)N2—C31.369 (2)
O4—H2O0.83 (3)C1—C41.505 (3)
O5—H3O0.79 (3)C3—C41.502 (3)
O5—H4O0.81 (3)C4—H4A0.9900
N1—H1N0.82 (3)C4—H4B0.9900
N1—C11.363 (2)
H1O—O4—H2O110 (3)O2—C2—N2121.94 (18)
H3O—O5—H4O105 (3)N1—C2—N2117.15 (17)
H1N—N1—C1117.9 (17)O3—C3—N2119.74 (18)
H1N—N1—C2116.1 (17)O3—C3—C4123.18 (17)
C1—N1—C2125.91 (16)N2—C3—C4117.07 (16)
H2N—N2—C2118.7 (17)C1—C4—C3116.25 (15)
H2N—N2—C3115.3 (17)C1—C4—H4A108.2
C2—N2—C3125.94 (17)C1—C4—H4B108.2
O1—C1—N1120.98 (17)C3—C4—H4A108.2
O1—C1—C4121.84 (17)C3—C4—H4B108.2
N1—C1—C4117.17 (16)H4A—C4—H4B107.4
O2—C2—N1120.91 (17)
C2—N1—C1—O1177.4 (2)C2—N2—C3—O3175.4 (2)
C2—N1—C1—C43.8 (3)C2—N2—C3—C45.4 (4)
C3—N2—C2—O2178.2 (2)O3—C3—C4—C1172.7 (2)
C3—N2—C2—N11.3 (4)N2—C3—C4—C18.2 (3)
C1—N1—C2—O2179.1 (2)O1—C1—C4—C3173.7 (2)
C1—N1—C2—N20.5 (4)N1—C1—C4—C37.4 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (3)1.98 (3)2.759 (2)161 (3)
O4—H2O···O1ii0.83 (3)2.03 (3)2.850 (2)171 (3)
O5—H3O···O40.79 (3)1.96 (3)2.743 (2)173 (4)
O5—H4O···O10.81 (3)1.99 (3)2.781 (2)165 (3)
N1—H1N···O3iii0.82 (3)2.00 (3)2.814 (2)175 (3)
N2—H2N···O5iv0.85 (3)1.88 (3)2.721 (2)173 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(170) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.580 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 5619 reflections
a = 6.1270 (5) Åθ = 2.3–28.3°
b = 12.7253 (11) ŵ = 0.15 mm1
c = 8.8633 (8) ÅT = 170 K
β = 93.0680 (16)°Block, colourless
V = 690.06 (10) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2124 independent reflections
Radiation source: fine-focus sealed tube2011 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
thin–slice ω scansθmax = 28.4°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 88
Tmin = 0.823, Tmax = 0.978k = 1616
9428 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.105H atoms treated by a mixture of independent and constrained refinement
S = 1.16 w = 1/[σ2(Fo2) + (0.0469P)2 + 0.1845P]
where P = (Fo2 + 2Fc2)/3
2124 reflections(Δ/σ)max = 0.001
120 parametersΔρmax = 0.30 e Å3
0 restraintsΔρmin = 0.33 e Å3
Crystal data top
C4H4N2O3·2H2OV = 690.06 (10) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1270 (5) ŵ = 0.15 mm1
b = 12.7253 (11) ÅT = 170 K
c = 8.8633 (8) Å0.53 × 0.42 × 0.15 mm
β = 93.0680 (16)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2124 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2011 reflections with I > 2σ(I)
Tmin = 0.823, Tmax = 0.978Rint = 0.024
9428 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.105H atoms treated by a mixture of independent and constrained refinement
S = 1.16Δρmax = 0.30 e Å3
2124 reflectionsΔρmin = 0.33 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2463 (2)0.55219 (7)0.47617 (10)0.0294 (3)
O20.2370 (2)0.44173 (7)0.95858 (10)0.0278 (3)
O30.2884 (2)0.79034 (7)0.88770 (11)0.0345 (3)
O40.2331 (2)0.88653 (8)0.23976 (12)0.0328 (3)
H1O0.245 (3)0.9170 (16)0.322 (2)0.039*
H2O0.241 (4)0.9287 (16)0.171 (2)0.039*
O50.2775 (3)0.67297 (9)0.21689 (11)0.0368 (3)
H3O0.257 (4)0.7371 (19)0.227 (2)0.044*
H4O0.259 (4)0.6454 (17)0.299 (2)0.044*
N10.2376 (2)0.49868 (8)0.71735 (11)0.0202 (2)
H1N0.232 (3)0.4357 (14)0.6897 (18)0.024*
N20.2547 (2)0.61732 (8)0.91989 (11)0.0192 (2)
H2N0.257 (3)0.6293 (13)1.015 (2)0.023*
C10.2447 (2)0.57488 (9)0.60978 (13)0.0190 (3)
C20.2423 (2)0.51518 (9)0.87116 (14)0.0188 (3)
C30.2661 (2)0.70408 (9)0.83007 (14)0.0203 (3)
C40.2473 (2)0.68715 (9)0.66209 (13)0.0195 (3)
H4A0.11140.72150.62170.023*
H4B0.37140.72330.61710.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0541 (7)0.0204 (5)0.0138 (4)0.0012 (5)0.0027 (5)0.0005 (3)
O20.0511 (7)0.0159 (4)0.0165 (4)0.0009 (5)0.0023 (5)0.0038 (3)
O30.0685 (8)0.0138 (5)0.0205 (5)0.0018 (5)0.0029 (5)0.0009 (3)
O40.0613 (8)0.0193 (5)0.0176 (5)0.0027 (5)0.0020 (5)0.0013 (4)
O50.0748 (9)0.0209 (5)0.0152 (5)0.0005 (6)0.0078 (6)0.0007 (4)
N10.0350 (6)0.0104 (5)0.0152 (5)0.0000 (5)0.0003 (5)0.0011 (4)
N20.0317 (6)0.0143 (5)0.0117 (5)0.0003 (5)0.0020 (4)0.0007 (4)
C10.0259 (7)0.0152 (5)0.0157 (6)0.0012 (5)0.0004 (5)0.0006 (4)
C20.0259 (7)0.0146 (5)0.0158 (5)0.0003 (5)0.0007 (5)0.0000 (4)
C30.0287 (7)0.0141 (5)0.0178 (6)0.0007 (5)0.0002 (5)0.0006 (4)
C40.0317 (7)0.0119 (5)0.0149 (6)0.0002 (5)0.0001 (5)0.0027 (4)
Geometric parameters (Å, º) top
O1—C11.2195 (15)N1—C21.3781 (16)
O2—C21.2156 (15)N2—H2N0.858 (18)
O3—C31.2153 (16)N2—C21.3704 (16)
O4—H1O0.83 (2)N2—C31.3651 (15)
O4—H2O0.82 (2)C1—C41.5018 (16)
O5—H3O0.83 (2)C3—C41.5026 (17)
O5—H4O0.82 (2)C4—H4A0.9900
N1—H1N0.838 (18)C4—H4B0.9900
N1—C11.3622 (15)
H1O—O4—H2O110 (2)O2—C2—N2122.09 (12)
H3O—O5—H4O107 (2)N1—C2—N2117.01 (11)
H1N—N1—C1118.5 (11)O3—C3—N2119.57 (12)
H1N—N1—C2115.7 (11)O3—C3—C4123.15 (11)
C1—N1—C2125.75 (10)N2—C3—C4117.27 (10)
H2N—N2—C2118.5 (11)C1—C4—C3116.19 (10)
H2N—N2—C3115.6 (11)C1—C4—H4A108.2
C2—N2—C3125.94 (11)C1—C4—H4B108.2
O1—C1—N1120.89 (11)C3—C4—H4A108.2
O1—C1—C4121.64 (11)C3—C4—H4B108.2
N1—C1—C4117.47 (10)H4A—C4—H4B107.4
O2—C2—N1120.90 (11)
C2—N1—C1—O1177.79 (14)C2—N2—C3—O3176.05 (15)
C2—N1—C1—C43.1 (2)C2—N2—C3—C44.7 (2)
C3—N2—C2—O2178.49 (15)O1—C1—C4—C3174.52 (14)
C3—N2—C2—N11.0 (2)N1—C1—C4—C36.3 (2)
C1—N1—C2—O2179.37 (14)O3—C3—C4—C1173.69 (15)
C1—N1—C2—N20.2 (2)N2—C3—C4—C17.0 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (2)1.97 (2)2.7611 (14)161 (2)
O4—H2O···O1ii0.82 (2)2.04 (2)2.8546 (14)171 (2)
O5—H3O···O40.83 (2)1.91 (2)2.7397 (16)174 (2)
O5—H4O···O10.82 (2)1.97 (2)2.7797 (15)167 (2)
N1—H1N···O3iii0.838 (18)1.975 (18)2.8117 (15)176.5 (16)
N2—H2N···O5iv0.858 (18)1.870 (18)2.7224 (14)172.3 (17)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(190) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.575 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 5464 reflections
a = 6.1377 (5) Åθ = 2.3–28.2°
b = 12.7306 (11) ŵ = 0.15 mm1
c = 8.8641 (8) ÅT = 190 K
β = 92.5280 (15)°Block, colourless
V = 691.94 (10) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2140 independent reflections
Radiation source: sealed tube1930 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 88
Tmin = 0.782, Tmax = 0.978k = 1616
9902 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037Hydrogen site location: mixed
wR(F2) = 0.105H atoms treated by a mixture of independent and constrained refinement
S = 1.06 w = 1/[σ2(Fo2) + (0.0601P)2 + 0.1202P]
where P = (Fo2 + 2Fc2)/3
2140 reflections(Δ/σ)max = 0.003
120 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C4H4N2O3·2H2OV = 691.94 (10) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1377 (5) ŵ = 0.15 mm1
b = 12.7306 (11) ÅT = 190 K
c = 8.8641 (8) Å0.53 × 0.42 × 0.15 mm
β = 92.5280 (15)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2140 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
1930 reflections with I > 2σ(I)
Tmin = 0.782, Tmax = 0.978Rint = 0.024
9902 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.105H atoms treated by a mixture of independent and constrained refinement
S = 1.06Δρmax = 0.26 e Å3
2140 reflectionsΔρmin = 0.28 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2470 (2)0.55228 (6)0.47638 (9)0.0343 (3)
O20.23972 (19)0.44178 (6)0.95852 (9)0.0319 (2)
O30.2813 (2)0.79045 (6)0.88757 (10)0.0405 (3)
O40.2365 (2)0.88652 (7)0.24005 (10)0.0376 (3)
H1O0.249 (3)0.9176 (14)0.325 (2)0.045*
H2O0.242 (3)0.9292 (15)0.170 (2)0.045*
O50.2721 (2)0.67279 (8)0.21639 (10)0.0432 (3)
H3O0.257 (3)0.7361 (18)0.227 (2)0.052*
H4O0.257 (3)0.6450 (16)0.301 (2)0.052*
N10.23998 (19)0.49869 (7)0.71727 (10)0.0237 (2)
H1N0.235 (3)0.4360 (13)0.6896 (16)0.028*
N20.25388 (19)0.61724 (7)0.91976 (10)0.0225 (2)
H2N0.256 (3)0.6303 (12)1.0161 (18)0.027*
C10.2458 (2)0.57501 (8)0.60989 (12)0.0221 (2)
C20.2438 (2)0.51508 (8)0.87111 (12)0.0217 (2)
C30.2633 (2)0.70402 (8)0.83004 (13)0.0237 (3)
C40.2478 (2)0.68704 (8)0.66203 (11)0.0231 (3)
H4A0.11290.72140.62130.028*
H4B0.37250.72300.61740.028*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0644 (7)0.0225 (4)0.0160 (4)0.0010 (5)0.0024 (4)0.0005 (3)
O20.0595 (7)0.0169 (4)0.0192 (4)0.0010 (4)0.0026 (4)0.0043 (3)
O30.0834 (9)0.0152 (4)0.0226 (4)0.0019 (5)0.0021 (5)0.0008 (3)
O40.0712 (8)0.0223 (4)0.0193 (4)0.0017 (5)0.0024 (5)0.0008 (3)
O50.0897 (10)0.0232 (4)0.0172 (4)0.0008 (6)0.0075 (5)0.0002 (3)
N10.0412 (6)0.0125 (4)0.0173 (5)0.0008 (4)0.0015 (4)0.0011 (3)
N20.0379 (6)0.0157 (4)0.0139 (4)0.0002 (4)0.0019 (4)0.0003 (3)
C10.0312 (6)0.0177 (5)0.0174 (5)0.0003 (5)0.0007 (5)0.0008 (4)
C20.0312 (6)0.0165 (5)0.0173 (5)0.0001 (5)0.0014 (4)0.0008 (4)
C30.0359 (7)0.0150 (5)0.0200 (5)0.0006 (5)0.0001 (5)0.0010 (4)
C40.0379 (7)0.0144 (5)0.0170 (5)0.0004 (5)0.0005 (5)0.0028 (4)
Geometric parameters (Å, º) top
O1—C11.2186 (14)N1—C21.3787 (14)
O2—C21.2139 (13)N2—H2N0.870 (16)
O3—C31.2157 (14)N2—C21.3707 (14)
O4—H1O0.852 (18)N2—C31.3640 (13)
O4—H2O0.827 (19)C1—C41.4992 (14)
O5—H3O0.82 (2)C3—C41.5037 (15)
O5—H4O0.84 (2)C4—H4A0.9900
N1—H1N0.835 (16)C4—H4B0.9900
N1—C11.3617 (14)
H1O—O4—H2O110.8 (18)O2—C2—N2122.04 (10)
H3O—O5—H4O107.2 (18)N1—C2—N2116.96 (9)
H1N—N1—C1118.6 (10)O3—C3—N2119.60 (10)
H1N—N1—C2115.7 (10)O3—C3—C4123.10 (10)
C1—N1—C2125.70 (9)N2—C3—C4117.29 (9)
H2N—N2—C2119.3 (10)C1—C4—C3116.20 (9)
H2N—N2—C3114.7 (10)C1—C4—H4A108.2
C2—N2—C3125.99 (9)C1—C4—H4B108.2
O1—C1—N1120.72 (10)C3—C4—H4A108.2
O1—C1—C4121.67 (9)C3—C4—H4B108.2
N1—C1—C4117.60 (9)H4A—C4—H4B107.4
O2—C2—N1121.00 (10)
C2—N1—C1—O1178.21 (13)C2—N2—C3—O3176.78 (13)
C2—N1—C1—C42.6 (2)C2—N2—C3—C43.9 (2)
C3—N2—C2—O2178.68 (14)O1—C1—C4—C3175.51 (13)
C3—N2—C2—N10.9 (2)N1—C1—C4—C35.29 (18)
C1—N1—C2—O2179.41 (13)O3—C3—C4—C1174.83 (13)
C1—N1—C2—N20.2 (2)N2—C3—C4—C15.89 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.852 (18)1.941 (19)2.7606 (13)161.1 (17)
O4—H2O···O1ii0.827 (19)2.037 (19)2.8567 (12)170.7 (17)
O5—H3O···O40.82 (2)1.92 (2)2.7384 (14)175 (2)
O5—H4O···O10.84 (2)1.96 (2)2.7785 (13)167.3 (18)
N1—H1N···O3iii0.835 (16)1.976 (16)2.8103 (13)176.8 (14)
N2—H2N···O5iv0.870 (16)1.854 (16)2.7204 (13)173.7 (15)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(200) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.583 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 4075 reflections
a = 6.1313 (12) Åθ = 2.3–28.2°
b = 12.703 (2) ŵ = 0.15 mm1
c = 8.8456 (17) ÅT = 200 K
β = 92.187 (4)°Block, colourless
V = 688.5 (2) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2456 independent reflections
Radiation source: fine-focus sealed tube2397 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 77
Tmin = 0.553, Tmax = 0.978k = 1616
7874 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.087Hydrogen site location: mixed
wR(F2) = 0.197H atoms treated by a mixture of independent and constrained refinement
S = 1.31 w = 1/[σ2(Fo2) + (0.0377P)2 + 1.4289P]
where P = (Fo2 + 2Fc2)/3
2456 reflections(Δ/σ)max = 0.004
120 parametersΔρmax = 0.50 e Å3
0 restraintsΔρmin = 0.58 e Å3
Crystal data top
C4H4N2O3·2H2OV = 688.5 (2) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1313 (12) ŵ = 0.15 mm1
b = 12.703 (2) ÅT = 200 K
c = 8.8456 (17) Å0.53 × 0.42 × 0.15 mm
β = 92.187 (4)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2456 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2397 reflections with I > 2σ(I)
Tmin = 0.553, Tmax = 0.978Rint = 0.029
7874 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0870 restraints
wR(F2) = 0.197H atoms treated by a mixture of independent and constrained refinement
S = 1.31Δρmax = 0.50 e Å3
2456 reflectionsΔρmin = 0.58 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2471 (6)0.55228 (17)0.4762 (2)0.0314 (6)
O20.2414 (5)0.44196 (16)0.9585 (2)0.0296 (6)
O30.2771 (6)0.79017 (17)0.8872 (3)0.0385 (7)
O40.2382 (6)0.88663 (18)0.2402 (3)0.0346 (7)
H1O0.256 (9)0.921 (3)0.322 (5)0.042*
H2O0.249 (9)0.930 (3)0.175 (5)0.042*
O50.2702 (7)0.6728 (2)0.2160 (3)0.0415 (8)
H3O0.246 (9)0.733 (4)0.225 (5)0.050*
H4O0.245 (9)0.645 (4)0.293 (5)0.050*
N10.2413 (6)0.49912 (18)0.7177 (3)0.0206 (6)
H1N0.243 (7)0.439 (3)0.689 (4)0.025*
N20.2537 (5)0.61703 (18)0.9196 (3)0.0193 (5)
H2N0.255 (7)0.630 (3)1.013 (4)0.023*
C10.2456 (6)0.5748 (2)0.6096 (3)0.0177 (6)
C20.2444 (6)0.5154 (2)0.8710 (3)0.0179 (6)
C30.2612 (6)0.7044 (2)0.8301 (3)0.0202 (6)
C40.2485 (6)0.6873 (2)0.6626 (3)0.0190 (6)
H4A0.37480.72300.61850.023*
H4B0.11480.72230.62120.023*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0622 (18)0.0206 (11)0.0116 (10)0.0009 (13)0.0049 (13)0.0011 (8)
O20.0586 (17)0.0145 (10)0.0156 (10)0.0024 (12)0.0010 (13)0.0043 (8)
O30.082 (2)0.0126 (10)0.0204 (11)0.0023 (14)0.0025 (15)0.0021 (9)
O40.069 (2)0.0170 (11)0.0177 (11)0.0053 (14)0.0011 (15)0.0022 (9)
O50.091 (3)0.0211 (12)0.0130 (11)0.0004 (17)0.0104 (16)0.0018 (9)
N10.0391 (17)0.0070 (10)0.0156 (11)0.0002 (12)0.0006 (13)0.0019 (8)
N20.0328 (16)0.0137 (11)0.0113 (11)0.0024 (12)0.0003 (12)0.0027 (9)
C10.0237 (17)0.0126 (12)0.0170 (13)0.0049 (13)0.0017 (14)0.0000 (10)
C20.0250 (17)0.0143 (12)0.0142 (12)0.0008 (13)0.0011 (14)0.0025 (10)
C30.0281 (18)0.0132 (12)0.0193 (13)0.0003 (14)0.0017 (14)0.0005 (10)
C40.0337 (19)0.0085 (11)0.0144 (13)0.0024 (14)0.0060 (15)0.0024 (9)
Geometric parameters (Å, º) top
O1—C11.215 (3)N1—H1N0.80 (4)
O2—C21.212 (3)N2—C21.362 (3)
O3—C31.203 (4)N2—C31.365 (4)
O4—H1O0.85 (5)N2—H2N0.85 (4)
O4—H2O0.80 (5)C1—C41.504 (4)
O5—H3O0.78 (5)C3—C41.497 (4)
O5—H4O0.79 (5)C4—H4A0.9900
N1—C11.357 (4)C4—H4B0.9900
N1—C21.371 (4)
H1O—O4—H2O104 (4)O2—C2—N1121.0 (2)
H3O—O5—H4O108 (5)N2—C2—N1117.0 (2)
C1—N1—C2126.2 (2)O3—C3—N2119.8 (3)
C1—N1—H1N117 (3)O3—C3—C4123.1 (3)
C2—N1—H1N117 (3)N2—C3—C4117.1 (2)
C2—N2—C3126.1 (2)C3—C4—C1116.4 (2)
C2—N2—H2N120 (2)C3—C4—H4A108.2
C3—N2—H2N114 (2)C1—C4—H4A108.2
O1—C1—N1121.2 (2)C3—C4—H4B108.2
O1—C1—C4121.7 (2)C1—C4—H4B108.2
N1—C1—C4117.1 (2)H4A—C4—H4B107.3
O2—C2—N2122.0 (3)
C2—N1—C1—O1178.4 (4)C2—N2—C3—O3177.3 (4)
C2—N1—C1—C41.6 (6)C2—N2—C3—C42.8 (6)
C3—N2—C2—O2178.9 (4)O3—C3—C4—C1175.7 (4)
C3—N2—C2—N10.3 (6)N2—C3—C4—C14.4 (5)
C1—N1—C2—O2179.6 (4)O1—C1—C4—C3176.1 (4)
C1—N1—C2—N20.3 (6)N1—C1—C4—C33.9 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.85 (5)1.96 (5)2.755 (3)155 (4)
O4—H2O···O1ii0.80 (5)2.05 (5)2.848 (3)173 (5)
O5—H3O···O40.78 (5)1.96 (5)2.733 (3)170 (6)
O5—H4O···O10.79 (5)2.00 (5)2.772 (3)165 (5)
N1—H1N···O3iii0.80 (4)2.01 (4)2.813 (3)175 (4)
N2—H2N···O5iv0.85 (4)1.87 (4)2.714 (3)174 (4)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(210) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.566 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2331 reflections
a = 6.1538 (15) Åθ = 2.3–28.3°
b = 12.747 (3) ŵ = 0.15 mm1
c = 8.877 (2) ÅT = 210 K
β = 91.627 (4)°Block, colourless
V = 696.0 (3) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2165 independent reflections
Radiation source: sealed tube2018 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.027
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 88
Tmin = 0.574, Tmax = 0.979k = 1616
7495 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.066Hydrogen site location: mixed
wR(F2) = 0.152H atoms treated by a mixture of independent and constrained refinement
S = 1.28 w = 1/[σ2(Fo2) + (0.0301P)2 + 0.8768P]
where P = (Fo2 + 2Fc2)/3
2165 reflections(Δ/σ)max = 0.007
120 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = 0.42 e Å3
Crystal data top
C4H4N2O3·2H2OV = 696.0 (3) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1538 (15) ŵ = 0.15 mm1
b = 12.747 (3) ÅT = 210 K
c = 8.877 (2) Å0.53 × 0.42 × 0.15 mm
β = 91.627 (4)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2165 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2018 reflections with I > 2σ(I)
Tmin = 0.574, Tmax = 0.979Rint = 0.027
7495 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0660 restraints
wR(F2) = 0.152H atoms treated by a mixture of independent and constrained refinement
S = 1.28Δρmax = 0.42 e Å3
2165 reflectionsΔρmin = 0.42 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2478 (5)0.55246 (14)0.47661 (18)0.0357 (5)
O20.2437 (5)0.44171 (13)0.95843 (18)0.0330 (5)
O30.2708 (5)0.79040 (14)0.8872 (2)0.0435 (6)
O40.2409 (6)0.88652 (15)0.2400 (2)0.0396 (5)
H1O0.253 (7)0.919 (3)0.319 (4)0.048*
H2O0.258 (7)0.931 (3)0.172 (4)0.048*
O50.2655 (6)0.67270 (17)0.2158 (2)0.0468 (7)
H3O0.249 (8)0.735 (3)0.223 (4)0.056*
H4O0.247 (8)0.647 (3)0.295 (4)0.056*
N10.2436 (5)0.49889 (14)0.7172 (2)0.0233 (5)
H1N0.243 (6)0.436 (2)0.689 (3)0.028*
N20.2527 (5)0.61701 (14)0.9194 (2)0.0224 (5)
H2N0.256 (6)0.628 (2)1.012 (4)0.027*
C10.2468 (5)0.57500 (16)0.6095 (2)0.0214 (5)
C20.2458 (5)0.51537 (16)0.8710 (2)0.0202 (5)
C30.2578 (5)0.70429 (17)0.8300 (3)0.0239 (5)
C40.2484 (6)0.68711 (16)0.6624 (2)0.0225 (5)
H4A0.37380.72230.61930.027*
H4B0.11730.72160.62130.027*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0721 (15)0.0221 (9)0.0132 (8)0.0030 (13)0.0049 (13)0.0006 (7)
O20.0666 (14)0.0159 (8)0.0166 (8)0.0016 (12)0.0037 (12)0.0041 (7)
O30.0956 (18)0.0135 (8)0.0209 (9)0.0002 (14)0.0035 (15)0.0014 (7)
O40.0791 (16)0.0201 (9)0.0198 (9)0.0052 (13)0.0026 (15)0.0029 (7)
O50.102 (2)0.0243 (10)0.0144 (9)0.0023 (18)0.0087 (16)0.0015 (7)
N10.0440 (13)0.0087 (8)0.0172 (9)0.0004 (12)0.0012 (12)0.0008 (7)
N20.0418 (13)0.0146 (9)0.0108 (9)0.0040 (11)0.0027 (11)0.0014 (7)
C10.0317 (14)0.0149 (10)0.0178 (11)0.0029 (12)0.0032 (13)0.0009 (8)
C20.0316 (14)0.0143 (10)0.0146 (10)0.0004 (12)0.0023 (12)0.0006 (8)
C30.0383 (15)0.0137 (10)0.0196 (11)0.0022 (13)0.0018 (13)0.0005 (8)
C40.0400 (15)0.0120 (9)0.0153 (10)0.0033 (13)0.0006 (13)0.0025 (8)
Geometric parameters (Å, º) top
O1—C11.214 (3)N1—C21.381 (3)
O2—C21.218 (3)N2—H2N0.83 (3)
O3—C31.211 (3)N2—C21.365 (3)
O4—H1O0.81 (4)N2—C31.367 (3)
O4—H2O0.83 (4)C1—C41.504 (3)
O5—H3O0.80 (4)C3—C41.503 (3)
O5—H4O0.79 (4)C4—H4A0.9800
N1—H1N0.84 (3)C4—H4B0.9800
N1—C11.362 (3)
H1O—O4—H2O106 (3)O2—C2—N2122.1 (2)
H3O—O5—H4O109 (4)N1—C2—N2117.05 (19)
H1N—N1—C1118.2 (19)O3—C3—N2119.8 (2)
H1N—N1—C2116.0 (19)O3—C3—C4123.2 (2)
C1—N1—C2125.83 (19)N2—C3—C4117.06 (19)
H2N—N2—C2118 (2)C1—C4—C3116.56 (18)
H2N—N2—C3115 (2)C1—C4—H4A108.2
C2—N2—C3126.19 (19)C1—C4—H4B108.2
O1—C1—N1120.9 (2)C3—C4—H4A108.2
O1—C1—C4121.9 (2)C3—C4—H4B108.2
N1—C1—C4117.22 (19)H4A—C4—H4B107.3
O2—C2—N1120.8 (2)
C2—N1—C1—O1178.9 (3)C2—N2—C3—O3177.6 (3)
C2—N1—C1—C41.2 (5)C2—N2—C3—C41.9 (5)
C3—N2—C2—O2179.3 (3)O3—C3—C4—C1176.2 (3)
C3—N2—C2—N10.0 (5)N2—C3—C4—C13.3 (5)
C1—N1—C2—O2179.6 (3)O1—C1—C4—C3177.1 (3)
C1—N1—C2—N20.3 (5)N1—C1—C4—C33.0 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (4)2.00 (4)2.767 (3)157 (3)
O4—H2O···O1ii0.83 (4)2.04 (4)2.861 (3)169 (4)
O5—H3O···O40.80 (4)1.94 (4)2.739 (3)174 (5)
O5—H4O···O10.79 (4)2.01 (4)2.782 (3)166 (4)
N1—H1N···O3iii0.84 (3)1.98 (3)2.815 (3)176 (3)
N2—H2N···O5iv0.83 (3)1.90 (3)2.724 (3)173 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(215) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.564 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3413 reflections
a = 6.1580 (9) Åθ = 2.3–28.3°
b = 12.7515 (18) ŵ = 0.15 mm1
c = 8.8763 (13) ÅT = 215 K
β = 91.263 (3)°Block, colourless
V = 696.83 (17) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2442 independent reflections
Radiation source: sealed tube2299 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 88
Tmin = 0.331, Tmax = 0.979k = 1616
8726 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.069Hydrogen site location: mixed
wR(F2) = 0.194H atoms treated by a mixture of independent and constrained refinement
S = 1.19 w = 1/[σ2(Fo2) + (0.0892P)2 + 0.5663P]
where P = (Fo2 + 2Fc2)/3
2442 reflections(Δ/σ)max = 0.006
120 parametersΔρmax = 0.41 e Å3
0 restraintsΔρmin = 0.44 e Å3
Crystal data top
C4H4N2O3·2H2OV = 696.83 (17) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1580 (9) ŵ = 0.15 mm1
b = 12.7515 (18) ÅT = 215 K
c = 8.8763 (13) Å0.53 × 0.42 × 0.15 mm
β = 91.263 (3)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2442 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2299 reflections with I > 2σ(I)
Tmin = 0.331, Tmax = 0.979Rint = 0.026
8726 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0690 restraints
wR(F2) = 0.194H atoms treated by a mixture of independent and constrained refinement
S = 1.19Δρmax = 0.41 e Å3
2442 reflectionsΔρmin = 0.44 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2484 (4)0.55256 (12)0.47633 (17)0.0379 (5)
O20.2450 (4)0.44181 (11)0.95858 (16)0.0351 (4)
O30.2659 (5)0.79038 (12)0.8873 (2)0.0468 (6)
O40.2431 (4)0.88661 (13)0.2403 (2)0.0413 (5)
H1O0.247 (6)0.920 (3)0.324 (4)0.050*
H2O0.252 (6)0.930 (3)0.168 (4)0.050*
O50.2611 (5)0.67261 (15)0.21545 (19)0.0497 (6)
H3O0.255 (7)0.738 (3)0.223 (4)0.060*
H4O0.249 (7)0.647 (3)0.299 (4)0.060*
N10.2454 (4)0.49886 (13)0.71734 (18)0.0252 (4)
H1N0.242 (5)0.437 (2)0.690 (3)0.030*
N20.2523 (4)0.61692 (12)0.91937 (18)0.0241 (4)
H2N0.249 (5)0.630 (2)1.011 (3)0.029*
C10.2481 (4)0.57491 (14)0.6098 (2)0.0234 (4)
C20.2470 (4)0.51546 (14)0.8712 (2)0.0224 (4)
C30.2568 (5)0.70427 (14)0.8298 (2)0.0255 (5)
C40.2490 (5)0.68708 (14)0.6624 (2)0.0247 (5)
H4A0.37470.72230.61920.030*
H4B0.11840.72150.62120.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0783 (13)0.0225 (8)0.0129 (7)0.0007 (10)0.0032 (10)0.0007 (6)
O20.0739 (13)0.0154 (7)0.0161 (7)0.0005 (9)0.0013 (10)0.0041 (5)
O30.1051 (17)0.0130 (7)0.0221 (8)0.0005 (11)0.0020 (12)0.0022 (6)
O40.0844 (14)0.0199 (8)0.0198 (8)0.0022 (10)0.0033 (12)0.0030 (6)
O50.1124 (19)0.0234 (9)0.0136 (8)0.0007 (13)0.0070 (13)0.0014 (6)
N10.0505 (12)0.0086 (7)0.0164 (8)0.0002 (9)0.0014 (10)0.0008 (6)
N20.0462 (11)0.0147 (8)0.0114 (7)0.0014 (9)0.0026 (9)0.0008 (6)
C10.0392 (12)0.0146 (8)0.0164 (9)0.0015 (10)0.0015 (10)0.0014 (7)
C20.0373 (12)0.0138 (8)0.0163 (9)0.0013 (9)0.0010 (10)0.0002 (6)
C30.0444 (13)0.0125 (8)0.0196 (9)0.0002 (10)0.0011 (11)0.0012 (7)
C40.0468 (13)0.0114 (8)0.0157 (9)0.0005 (10)0.0014 (11)0.0028 (6)
Geometric parameters (Å, º) top
O1—C11.219 (2)N1—C21.382 (2)
O2—C21.218 (2)N2—H2N0.83 (3)
O3—C31.211 (2)N2—C21.363 (2)
O4—H1O0.86 (4)N2—C31.369 (2)
O4—H2O0.85 (4)C1—C41.504 (2)
O5—H3O0.83 (4)C3—C41.502 (3)
O5—H4O0.82 (4)C4—H4A0.9800
N1—H1N0.83 (3)C4—H4B0.9800
N1—C11.361 (2)
H1O—O4—H2O109 (3)O2—C2—N2122.17 (18)
H3O—O5—H4O109 (4)N1—C2—N2117.08 (17)
H1N—N1—C1118.5 (19)O3—C3—N2119.63 (19)
H1N—N1—C2115.8 (19)O3—C3—C4123.30 (18)
C1—N1—C2125.73 (16)N2—C3—C4117.07 (16)
H2N—N2—C2120 (2)C1—C4—C3116.45 (15)
H2N—N2—C3114 (2)C1—C4—H4A108.2
C2—N2—C3126.22 (17)C1—C4—H4B108.2
O1—C1—N1121.03 (18)C3—C4—H4A108.2
O1—C1—C4121.59 (17)C3—C4—H4B108.2
N1—C1—C4117.38 (16)H4A—C4—H4B107.3
O2—C2—N1120.74 (17)
C2—N1—C1—O1179.3 (3)C2—N2—C3—O3178.5 (3)
C2—N1—C1—C41.1 (4)C2—N2—C3—C41.8 (4)
C3—N2—C2—O2179.4 (3)O3—C3—C4—C1177.4 (3)
C3—N2—C2—N10.2 (4)N2—C3—C4—C12.9 (4)
C1—N1—C2—O2179.8 (3)O1—C1—C4—C3177.8 (3)
C1—N1—C2—N20.2 (4)N1—C1—C4—C32.6 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.86 (4)1.95 (4)2.763 (2)159 (3)
O4—H2O···O1ii0.85 (4)2.02 (4)2.860 (2)169 (3)
O5—H3O···O40.83 (4)1.91 (4)2.740 (3)179 (4)
O5—H4O···O10.82 (4)1.98 (4)2.778 (2)166 (4)
N1—H1N···O3iii0.83 (3)1.99 (3)2.816 (2)177 (3)
N2—H2N···O5iv0.83 (3)1.89 (3)2.722 (2)173 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(216) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.569 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2043 reflections
a = 6.1567 (16) Åθ = 2.3–28.5°
b = 12.733 (3) ŵ = 0.15 mm1
c = 8.865 (2) ÅT = 216 K
β = 91.180 (5)°Block, colourless
V = 694.8 (3) Å30.53 × 0.42 × 0.15 mm
Z = 4
Data collection top
Bruker SMART 1K CCD
diffractometer
2209 independent reflections
Radiation source: sealed tube2058 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
thin–slice ω scansθmax = 28.7°, θmin = 2.8°
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
h = 88
Tmin = 0.492, Tmax = 0.979k = 1616
7321 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.068Hydrogen site location: mixed
wR(F2) = 0.181H atoms treated by a mixture of independent and constrained refinement
S = 1.30 w = 1/[σ2(Fo2) + (0.062P)2 + 0.4139P]
where P = (Fo2 + 2Fc2)/3
2209 reflections(Δ/σ)max = 0.002
120 parametersΔρmax = 0.33 e Å3
0 restraintsΔρmin = 0.47 e Å3
Crystal data top
C4H4N2O3·2H2OV = 694.8 (3) Å3
Mr = 164.12Z = 4
Monoclinic, P21/nMo Kα radiation
a = 6.1567 (16) ŵ = 0.15 mm1
b = 12.733 (3) ÅT = 216 K
c = 8.865 (2) Å0.53 × 0.42 × 0.15 mm
β = 91.180 (5)°
Data collection top
Bruker SMART 1K CCD
diffractometer
2209 independent reflections
Absorption correction: multi-scan
TWINABS; Sheldrick (2002)
2058 reflections with I > 2σ(I)
Tmin = 0.492, Tmax = 0.979Rint = 0.024
7321 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0680 restraints
wR(F2) = 0.181H atoms treated by a mixture of independent and constrained refinement
S = 1.30Δρmax = 0.33 e Å3
2209 reflectionsΔρmin = 0.47 e Å3
120 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2511 (5)0.55242 (13)0.47649 (18)0.0372 (5)
O20.2545 (5)0.44172 (12)0.95856 (18)0.0340 (5)
O30.2341 (5)0.79039 (13)0.8873 (2)0.0458 (6)
O40.2570 (5)0.88662 (14)0.2402 (2)0.0401 (5)
H1O0.247 (7)0.918 (3)0.324 (4)0.048*
H2O0.230 (7)0.929 (3)0.171 (4)0.048*
O50.2372 (6)0.67273 (16)0.2155 (2)0.0483 (6)
H3O0.266 (8)0.732 (4)0.225 (5)0.058*
H4O0.265 (8)0.647 (3)0.299 (5)0.058*
N10.2539 (5)0.49891 (14)0.7176 (2)0.0244 (4)
H1N0.251 (6)0.438 (3)0.689 (3)0.029*
N20.2481 (5)0.61712 (13)0.9195 (2)0.0233 (4)
H2N0.243 (6)0.627 (2)1.016 (4)0.028*
C10.2529 (5)0.57487 (15)0.6098 (2)0.0215 (4)
C20.2531 (5)0.51522 (15)0.8710 (2)0.0214 (4)
C30.2434 (5)0.70403 (16)0.8296 (3)0.0250 (5)
C40.2504 (6)0.68705 (15)0.6623 (2)0.0235 (5)
H4A0.38020.72200.62450.028*
H4B0.12380.72180.61570.028*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0750 (13)0.0221 (8)0.0145 (8)0.0034 (13)0.0035 (14)0.0006 (6)
O20.0684 (12)0.0152 (8)0.0182 (8)0.0018 (11)0.0040 (14)0.0039 (6)
O30.1024 (17)0.0116 (8)0.0235 (9)0.0022 (14)0.0027 (17)0.0015 (7)
O40.0789 (14)0.0198 (8)0.0213 (8)0.0064 (13)0.0040 (17)0.0016 (7)
O50.1052 (19)0.0227 (9)0.0166 (9)0.0006 (17)0.0104 (18)0.0011 (7)
N10.0474 (12)0.0087 (8)0.0172 (9)0.0004 (12)0.0012 (13)0.0003 (6)
N20.0437 (11)0.0130 (8)0.0132 (8)0.0026 (11)0.0020 (12)0.0011 (6)
C10.0333 (12)0.0140 (9)0.0169 (10)0.0039 (12)0.0017 (13)0.0006 (7)
C20.0346 (12)0.0124 (9)0.0172 (9)0.0005 (11)0.0015 (14)0.0006 (7)
C30.0421 (13)0.0124 (9)0.0203 (10)0.0028 (13)0.0038 (15)0.0005 (8)
C40.0417 (13)0.0114 (9)0.0176 (10)0.0035 (13)0.0034 (14)0.0031 (7)
Geometric parameters (Å, º) top
O1—C11.215 (3)N1—C21.376 (3)
O2—C21.216 (3)N2—H2N0.87 (3)
O3—C31.215 (3)N2—C21.367 (3)
O4—H1O0.85 (4)N2—C31.364 (3)
O4—H2O0.83 (4)C1—C41.503 (3)
O5—H3O0.78 (4)C3—C41.500 (3)
O5—H4O0.82 (4)C4—H4A0.9800
N1—H1N0.81 (3)C4—H4B0.9800
N1—C11.360 (3)
H1O—O4—H2O109 (3)O2—C2—N2122.0 (2)
H3O—O5—H4O105 (4)N1—C2—N2117.03 (18)
H1N—N1—C1117 (2)O3—C3—N2119.3 (2)
H1N—N1—C2117 (2)O3—C3—C4123.3 (2)
C1—N1—C2125.97 (18)N2—C3—C4117.41 (18)
H2N—N2—C2117 (2)C1—C4—C3116.35 (17)
H2N—N2—C3117 (2)C1—C4—H4A108.2
C2—N2—C3125.90 (18)C1—C4—H4B108.2
O1—C1—N1121.06 (19)C3—C4—H4A108.2
O1—C1—C4121.65 (19)C3—C4—H4B108.2
N1—C1—C4117.29 (18)H4A—C4—H4B107.4
O2—C2—N1120.97 (19)
C2—N1—C1—O1179.1 (3)C2—N2—C3—O3178.3 (3)
C2—N1—C1—C40.1 (5)C2—N2—C3—C41.7 (5)
C3—N2—C2—O2179.1 (3)O3—C3—C4—C1177.7 (3)
C3—N2—C2—N10.1 (5)N2—C3—C4—C12.4 (5)
C1—N1—C2—O2179.9 (3)O1—C1—C4—C3177.5 (3)
C1—N1—C2—N20.9 (5)N1—C1—C4—C31.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.85 (4)1.95 (4)2.763 (3)161 (3)
O4—H2O···O1ii0.83 (4)2.05 (4)2.854 (3)163 (4)
O5—H3O···O40.78 (4)1.98 (4)2.735 (3)165 (5)
O5—H4O···O10.82 (4)1.98 (4)2.775 (3)160 (4)
N1—H1N···O3iii0.81 (3)2.01 (3)2.815 (3)176 (4)
N2—H2N···O5iv0.87 (3)1.86 (3)2.719 (3)170 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(217) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.551 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 4044 reflections
a = 6.1770 (18) Åθ = 2.3–28.4°
b = 12.785 (4) ŵ = 0.14 mm1
c = 8.898 (3) ÅT = 217 K
V = 702.7 (3) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
889 independent reflections
Radiation source: sealed tube800 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.050
thin–slice ω scansθmax = 28.4°, θmin = 2.8°
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
h = 87
Tmin = 0.321, Tmax = 0.979k = 1616
5924 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.061Hydrogen site location: difference Fourier map
wR(F2) = 0.154Only H-atom coordinates refined
S = 1.25 w = 1/[σ2(Fo2) + (0.0547P)2 + 0.6287P]
where P = (Fo2 + 2Fc2)/3
889 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.35 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C4H4N2O3·2H2OV = 702.7 (3) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.1770 (18) ŵ = 0.14 mm1
b = 12.785 (4) ÅT = 217 K
c = 8.898 (3) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
889 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
800 reflections with I > 2σ(I)
Tmin = 0.321, Tmax = 0.979Rint = 0.050
5924 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0610 restraints
wR(F2) = 0.154Only H-atom coordinates refined
S = 1.25Δρmax = 0.35 e Å3
889 reflectionsΔρmin = 0.28 e Å3
82 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55228 (16)0.4767 (2)0.0399 (7)
O20.25000.44191 (15)0.9584 (2)0.0366 (7)
O30.25000.79033 (16)0.8872 (2)0.0516 (9)
O40.25000.88660 (17)0.2405 (3)0.0435 (8)
H1O0.25000.914 (3)0.326 (5)0.052*
H2O0.25000.928 (4)0.169 (5)0.052*
O50.25000.6727 (2)0.2154 (3)0.0517 (9)
H3O0.25000.737 (4)0.221 (5)0.062*
H4O0.25000.651 (4)0.296 (6)0.062*
N10.25000.49888 (17)0.7173 (2)0.0262 (6)
H1N0.25000.438 (3)0.690 (4)0.031*
N20.25000.61720 (17)0.9196 (2)0.0252 (6)
H2N0.25000.629 (3)1.021 (4)0.030*
C10.25000.5749 (2)0.6102 (3)0.0237 (6)
C20.25000.51549 (19)0.8712 (3)0.0240 (6)
C30.25000.70413 (19)0.8298 (3)0.0277 (7)
C40.25000.6873 (2)0.6626 (3)0.0250 (7)
H10.124 (4)0.7146 (17)0.623 (3)0.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.085 (2)0.0214 (10)0.0134 (9)0.0000.0000.0003 (7)
O20.077 (2)0.0145 (9)0.0184 (10)0.0000.0000.0042 (7)
O30.120 (3)0.0122 (10)0.0228 (11)0.0000.0000.0013 (8)
O40.091 (2)0.0200 (10)0.0195 (10)0.0000.0000.0012 (8)
O50.117 (3)0.0227 (11)0.0158 (11)0.0000.0000.0008 (8)
N10.0527 (18)0.0085 (10)0.0173 (11)0.0000.0000.0013 (8)
N20.0500 (18)0.0129 (10)0.0128 (10)0.0000.0000.0002 (8)
C10.0410 (19)0.0140 (11)0.0161 (12)0.0000.0000.0019 (9)
C20.0425 (18)0.0130 (11)0.0164 (12)0.0000.0000.0001 (9)
C30.053 (2)0.0110 (11)0.0194 (13)0.0000.0000.0017 (9)
C40.045 (2)0.0117 (11)0.0178 (13)0.0000.0000.0023 (9)
Geometric parameters (Å, º) top
O1—C11.222 (3)N1—C11.361 (3)
O2—C21.219 (3)N1—C21.386 (3)
O3—C31.215 (3)N2—H2N0.92 (4)
O4—H1O0.84 (5)N2—C21.370 (3)
O4—H2O0.83 (5)N2—C31.369 (3)
O5—H3O0.82 (5)C1—C41.511 (3)
O5—H4O0.77 (5)C3—C41.504 (4)
N1—H1N0.81 (4)C4—H10.92 (3)
H1O—O4—H2O115 (4)N1—C1—C4117.6 (2)
H3O—O5—H4O108 (5)O2—C2—N1120.7 (2)
H1N—N1—C1118 (3)O2—C2—N2122.2 (2)
H1N—N1—C2116 (3)N1—C2—N2117.1 (2)
C1—N1—C2125.6 (2)O3—C3—N2119.4 (3)
H2N—N2—C2118 (2)O3—C3—C4123.1 (2)
H2N—N2—C3116 (2)N2—C3—C4117.5 (2)
C2—N2—C3126.0 (2)C1—C4—C3116.2 (2)
O1—C1—N1120.7 (2)C1—C4—H1104.1 (15)
O1—C1—C4121.7 (2)C3—C4—H1108.7 (15)
C2—N1—C1—O1180.0C2—N2—C3—O3180.000 (1)
C2—N1—C1—C40.000 (1)C2—N2—C3—C40.000 (2)
C3—N2—C2—O2180.000 (1)O3—C3—C4—C1180.000 (1)
C3—N2—C2—N10.000 (1)N2—C3—C4—C10.000 (1)
C1—N1—C2—O2180.0O1—C1—C4—C3180.000 (1)
C1—N1—C2—N20.000 (1)N1—C1—C4—C30.000 (1)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.84 (5)1.95 (5)2.771 (3)166 (4)
O4—H2O···O1ii0.83 (5)2.05 (5)2.867 (3)169 (4)
O5—H3O···O40.82 (5)1.92 (6)2.744 (3)178 (5)
O5—H4O···O10.77 (5)2.04 (5)2.788 (3)163 (5)
N1—H1N···O3iii0.81 (4)2.01 (4)2.824 (3)178 (3)
N2—H2N···O5iv0.92 (4)1.81 (4)2.726 (3)172 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(218) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.562 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 3921 reflections
a = 6.1626 (19) Åθ = 2.3–28.3°
b = 12.757 (4) ŵ = 0.15 mm1
c = 8.876 (3) ÅT = 218 K
V = 697.8 (4) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
904 independent reflections
Radiation source: sealed tube829 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.047
thin–slice ω scansθmax = 28.2°, θmin = 2.8°
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
h = 78
Tmin = 0.351, Tmax = 0.979k = 1616
5224 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.054Hydrogen site location: difference Fourier map
wR(F2) = 0.137Only H-atom coordinates refined
S = 1.17 w = 1/[σ2(Fo2) + (0.0601P)2 + 0.4239P]
where P = (Fo2 + 2Fc2)/3
904 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C4H4N2O3·2H2OV = 697.8 (4) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.1626 (19) ŵ = 0.15 mm1
b = 12.757 (4) ÅT = 218 K
c = 8.876 (3) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
904 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
829 reflections with I > 2σ(I)
Tmin = 0.351, Tmax = 0.979Rint = 0.047
5224 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0540 restraints
wR(F2) = 0.137Only H-atom coordinates refined
S = 1.17Δρmax = 0.29 e Å3
904 reflectionsΔρmin = 0.28 e Å3
82 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55228 (13)0.47671 (19)0.0397 (6)
O20.25000.44188 (12)0.95843 (18)0.0365 (5)
O30.25000.79037 (13)0.8871 (2)0.0510 (7)
O40.25000.88652 (15)0.2405 (2)0.0441 (6)
H1O0.25000.916 (3)0.324 (4)0.053*
H2O0.25000.928 (3)0.166 (4)0.053*
O50.25000.67261 (16)0.2155 (2)0.0524 (7)
H3O0.25000.735 (4)0.221 (5)0.063*
H4O0.25000.648 (3)0.298 (5)0.063*
N10.25000.49887 (14)0.7173 (2)0.0270 (5)
H1N0.25000.438 (3)0.689 (3)0.032*
N20.25000.61718 (14)0.9196 (2)0.0254 (5)
H2N0.25000.629 (2)1.022 (4)0.031*
C10.25000.57481 (16)0.6100 (2)0.0246 (5)
C20.25000.51532 (16)0.8711 (2)0.0238 (5)
C30.25000.70409 (16)0.8298 (3)0.0277 (6)
C40.25000.68728 (16)0.6624 (2)0.0258 (5)
H10.125 (4)0.7158 (14)0.622 (2)0.031*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0832 (16)0.0220 (9)0.0138 (8)0.0000.0000.0003 (6)
O20.0762 (15)0.0151 (8)0.0181 (8)0.0000.0000.0045 (6)
O30.117 (2)0.0130 (8)0.0227 (9)0.0000.0000.0016 (6)
O40.0914 (18)0.0213 (9)0.0197 (8)0.0000.0000.0016 (7)
O50.118 (2)0.0230 (9)0.0160 (9)0.0000.0000.0004 (7)
N10.0548 (14)0.0097 (8)0.0166 (9)0.0000.0000.0014 (7)
N20.0495 (13)0.0129 (8)0.0139 (8)0.0000.0000.0003 (7)
C10.0436 (14)0.0148 (9)0.0154 (10)0.0000.0000.0013 (8)
C20.0407 (14)0.0138 (9)0.0168 (10)0.0000.0000.0002 (8)
C30.0516 (16)0.0120 (9)0.0195 (10)0.0000.0000.0016 (8)
C40.0479 (16)0.0123 (9)0.0172 (10)0.0000.0000.0028 (8)
Geometric parameters (Å, º) top
O1—C11.217 (3)N1—C11.359 (3)
O2—C21.216 (3)N1—C21.381 (3)
O3—C31.213 (3)N2—H2N0.92 (3)
O4—H1O0.83 (4)N2—C21.369 (3)
O4—H2O0.85 (4)N2—C31.366 (3)
O5—H3O0.80 (5)C1—C41.508 (3)
O5—H4O0.79 (4)C3—C41.500 (3)
N1—H1N0.82 (3)C4—H10.92 (2)
H1O—O4—H2O114 (4)N1—C1—C4117.51 (19)
H3O—O5—H4O110 (4)O2—C2—N1120.87 (19)
H1N—N1—C1118 (2)O2—C2—N2122.0 (2)
H1N—N1—C2117 (2)N1—C2—N2117.09 (19)
C1—N1—C2125.78 (18)O3—C3—N2119.4 (2)
H2N—N2—C2117.7 (19)O3—C3—C4123.0 (2)
H2N—N2—C3116.3 (19)N2—C3—C4117.52 (18)
C2—N2—C3125.92 (19)C1—C4—C3116.19 (18)
O1—C1—N1120.9 (2)C1—C4—H1104.8 (12)
O1—C1—C4121.63 (19)C3—C4—H1109.2 (13)
C2—N1—C1—O1180.0C2—N2—C3—O3180.000 (1)
C2—N1—C1—C40.000 (1)C2—N2—C3—C40.000 (1)
C3—N2—C2—O2180.0O3—C3—C4—C1180.000 (1)
C3—N2—C2—N10.000 (1)N2—C3—C4—C10.000 (1)
C1—N1—C2—O2180.0O1—C1—C4—C3180.000 (1)
C1—N1—C2—N20.000 (1)N1—C1—C4—C30.000 (1)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (4)1.96 (4)2.764 (3)162 (4)
O4—H2O···O1ii0.85 (4)2.03 (4)2.861 (3)168 (4)
O5—H3O···O40.80 (5)1.94 (5)2.738 (3)179 (4)
O5—H4O···O10.79 (4)2.01 (5)2.780 (3)166 (4)
N1—H1N···O3iii0.82 (3)2.00 (3)2.817 (3)178 (3)
N2—H2N···O5iv0.92 (3)1.81 (3)2.720 (3)171 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(219) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.562 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 4241 reflections
a = 6.1624 (15) Åθ = 2.3–28.3°
b = 12.757 (3) ŵ = 0.15 mm1
c = 8.878 (2) ÅT = 219 K
V = 697.9 (3) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
914 independent reflections
Radiation source: sealed tube865 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
SADBAS; Sheldrick (2003)
h = 87
Tmin = 0.353, Tmax = 0.979k = 1616
5236 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.066Hydrogen site location: difference Fourier map
wR(F2) = 0.158Only H-atom coordinates refined
S = 1.32 w = 1/[σ2(Fo2) + (0.0488P)2 + 0.7204P]
where P = (Fo2 + 2Fc2)/3
914 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = 0.33 e Å3
Crystal data top
C4H4N2O3·2H2OV = 697.9 (3) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.1624 (15) ŵ = 0.15 mm1
b = 12.757 (3) ÅT = 219 K
c = 8.878 (2) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
914 independent reflections
Absorption correction: multi-scan
SADBAS; Sheldrick (2003)
865 reflections with I > 2σ(I)
Tmin = 0.353, Tmax = 0.979Rint = 0.046
5236 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0660 restraints
wR(F2) = 0.158Only H-atom coordinates refined
S = 1.32Δρmax = 0.32 e Å3
914 reflectionsΔρmin = 0.33 e Å3
82 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55238 (17)0.4767 (2)0.0399 (7)
O20.25000.44185 (16)0.9583 (2)0.0368 (7)
O30.25000.79041 (16)0.8872 (3)0.0507 (9)
O40.25000.88667 (19)0.2402 (3)0.0436 (8)
H1O0.25000.916 (4)0.323 (6)0.052*
H2O0.25000.932 (4)0.165 (5)0.052*
O50.25000.6725 (2)0.2153 (3)0.0531 (10)
H3O0.25000.732 (5)0.222 (6)0.064*
H4O0.25000.650 (4)0.298 (6)0.064*
N10.25000.49897 (18)0.7173 (3)0.0268 (6)
H1N0.25000.438 (3)0.689 (4)0.032*
N20.25000.61709 (18)0.9195 (3)0.0257 (6)
H2N0.25000.628 (3)1.018 (5)0.031*
C10.25000.5748 (2)0.6099 (3)0.0239 (7)
C20.25000.5154 (2)0.8712 (3)0.0238 (7)
C30.25000.7041 (2)0.8296 (3)0.0275 (7)
C40.25000.6872 (2)0.6627 (3)0.0251 (7)
H10.128 (4)0.7142 (18)0.622 (3)0.030*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.084 (2)0.0219 (11)0.0135 (10)0.0000.0000.0001 (8)
O20.0775 (19)0.0152 (10)0.0177 (10)0.0000.0000.0043 (8)
O30.118 (3)0.0121 (10)0.0225 (11)0.0000.0000.0019 (8)
O40.091 (2)0.0205 (11)0.0197 (11)0.0000.0000.0021 (9)
O50.121 (3)0.0229 (11)0.0155 (11)0.0000.0000.0010 (9)
N10.0550 (18)0.0086 (10)0.0167 (12)0.0000.0000.0011 (8)
N20.0510 (17)0.0133 (11)0.0127 (11)0.0000.0000.0003 (9)
C10.0419 (18)0.0135 (12)0.0164 (13)0.0000.0000.0012 (10)
C20.0416 (18)0.0131 (12)0.0166 (13)0.0000.0000.0003 (10)
C30.051 (2)0.0122 (12)0.0192 (13)0.0000.0000.0012 (10)
C40.046 (2)0.0122 (12)0.0167 (13)0.0000.0000.0023 (10)
Geometric parameters (Å, º) top
O1—C11.217 (4)N1—C11.359 (3)
O2—C21.217 (3)N1—C21.382 (4)
O3—C31.214 (3)N2—H2N0.88 (4)
O4—H1O0.83 (5)N2—C21.366 (3)
O4—H2O0.89 (5)N2—C31.367 (3)
O5—H3O0.76 (6)C1—C41.509 (4)
O5—H4O0.79 (6)C3—C41.498 (4)
N1—H1N0.82 (4)C4—H10.90 (3)
H1O—O4—H2O112 (4)N1—C1—C4117.3 (2)
H3O—O5—H4O108 (5)O2—C2—N1120.8 (2)
H1N—N1—C1118 (3)O2—C2—N2122.2 (3)
H1N—N1—C2117 (3)N1—C2—N2117.1 (2)
C1—N1—C2125.8 (2)O3—C3—N2119.4 (3)
H2N—N2—C2118 (3)O3—C3—C4123.1 (3)
H2N—N2—C3116 (3)N2—C3—C4117.5 (2)
C2—N2—C3126.0 (2)C1—C4—C3116.4 (2)
O1—C1—N1121.0 (3)C1—C4—H1103.9 (16)
O1—C1—C4121.7 (2)C3—C4—H1109.8 (16)
C2—N1—C1—O1180.000 (1)C2—N2—C3—O3180.000 (1)
C2—N1—C1—C40.000 (1)C2—N2—C3—C40.000 (2)
C3—N2—C2—O2180.000 (1)O3—C3—C4—C1180.000 (2)
C3—N2—C2—N10.000 (1)N2—C3—C4—C10.000 (1)
C1—N1—C2—O2180.000 (1)O1—C1—C4—C3180.000 (1)
C1—N1—C2—N20.000 (1)N1—C1—C4—C30.000 (1)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (5)1.97 (5)2.767 (3)162 (5)
O4—H2O···O1ii0.89 (5)1.98 (5)2.860 (3)170 (4)
O5—H3O···O40.76 (6)1.98 (6)2.741 (4)179 (6)
O5—H4O···O10.79 (6)2.02 (6)2.781 (3)164 (5)
N1—H1N···O3iii0.82 (4)2.00 (4)2.818 (3)178 (4)
N2—H2N···O5iv0.88 (4)1.84 (4)2.720 (3)172 (4)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(220) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.560 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 4044 reflections
a = 6.1665 (12) Åθ = 2.3–28.3°
b = 12.763 (2) ŵ = 0.15 mm1
c = 8.8814 (17) ÅT = 220 K
V = 699.0 (2) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
923 independent reflections
Radiation source: sealed tube824 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.043
thin–slice ω scansθmax = 28.4°, θmin = 2.8°
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
h = 88
Tmin = 0.452, Tmax = 0.979k = 1615
5578 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.045Hydrogen site location: difference Fourier map
wR(F2) = 0.124Only H-atom coordinates refined
S = 1.09 w = 1/[σ2(Fo2) + (0.0685P)2 + 0.2425P]
where P = (Fo2 + 2Fc2)/3
923 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.26 e Å3
0 restraintsΔρmin = 0.28 e Å3
Crystal data top
C4H4N2O3·2H2OV = 699.0 (2) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.1665 (12) ŵ = 0.15 mm1
b = 12.763 (2) ÅT = 220 K
c = 8.8814 (17) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
923 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
824 reflections with I > 2σ(I)
Tmin = 0.452, Tmax = 0.979Rint = 0.043
5578 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0450 restraints
wR(F2) = 0.124Only H-atom coordinates refined
S = 1.09Δρmax = 0.26 e Å3
923 reflectionsΔρmin = 0.28 e Å3
82 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55228 (10)0.47671 (15)0.0410 (5)
O20.25000.44186 (10)0.95839 (15)0.0383 (4)
O30.25000.79037 (10)0.88713 (17)0.0519 (6)
O40.25000.88645 (12)0.24042 (18)0.0454 (5)
H1O0.25000.917 (2)0.321 (4)0.055*
H2O0.25000.929 (3)0.168 (4)0.055*
O50.25000.67261 (13)0.21539 (17)0.0534 (6)
H3O0.25000.736 (3)0.220 (4)0.064*
H4O0.25000.648 (3)0.298 (4)0.064*
N10.25000.49880 (12)0.71729 (16)0.0282 (4)
H1N0.25000.438 (2)0.688 (3)0.034*
N20.25000.61723 (11)0.91948 (17)0.0270 (4)
H2N0.25000.631 (2)1.021 (3)0.032*
C10.25000.57491 (13)0.60995 (19)0.0259 (4)
C20.25000.51520 (13)0.8713 (2)0.0255 (4)
C30.25000.70406 (13)0.8297 (2)0.0290 (4)
C40.25000.68711 (13)0.6623 (2)0.0269 (4)
H10.127 (3)0.7160 (12)0.6216 (19)0.032*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0840 (12)0.0237 (7)0.0154 (7)0.0000.0000.0007 (5)
O20.0794 (12)0.0158 (6)0.0197 (7)0.0000.0000.0050 (5)
O30.1180 (17)0.0139 (7)0.0238 (8)0.0000.0000.0009 (5)
O40.0928 (14)0.0224 (7)0.0210 (7)0.0000.0000.0014 (6)
O50.1193 (18)0.0238 (7)0.0171 (7)0.0000.0000.0004 (5)
N10.0562 (11)0.0117 (7)0.0168 (8)0.0000.0000.0011 (5)
N20.0521 (10)0.0140 (7)0.0148 (7)0.0000.0000.0006 (5)
C10.0441 (11)0.0162 (8)0.0172 (8)0.0000.0000.0009 (6)
C20.0447 (11)0.0143 (8)0.0176 (8)0.0000.0000.0003 (6)
C30.0536 (12)0.0133 (7)0.0203 (9)0.0000.0000.0015 (6)
C40.0488 (12)0.0142 (7)0.0178 (8)0.0000.0000.0032 (6)
Geometric parameters (Å, º) top
O1—C11.218 (2)N1—C21.383 (2)
O2—C21.214 (2)N1—H1N0.82 (3)
O3—C31.214 (2)N2—C31.365 (2)
O4—H1O0.81 (3)N2—C21.371 (2)
O4—H2O0.85 (3)N2—H2N0.92 (3)
O5—H3O0.81 (4)C1—C41.506 (2)
O5—H4O0.80 (4)C3—C41.502 (2)
N1—C11.361 (2)C4—H10.917 (17)
H1O—O4—H2O111 (3)N1—C1—C4117.54 (15)
H3O—O5—H4O110 (3)O2—C2—N2122.21 (17)
C1—N1—C2125.76 (15)O2—C2—N1120.88 (16)
C1—N1—H1N117.2 (18)N2—C2—N1116.91 (15)
C2—N1—H1N117.0 (18)O3—C3—N2119.42 (17)
C3—N2—C2126.06 (15)O3—C3—C4123.13 (16)
C3—N2—H2N115.0 (16)N2—C3—C4117.45 (15)
C2—N2—H2N119.0 (16)C3—C4—C1116.28 (14)
O1—C1—N1120.74 (16)C3—C4—H1109.4 (10)
O1—C1—C4121.71 (16)C1—C4—H1105.1 (10)
C2—N1—C1—O1180.0C2—N2—C3—O3180.0
C2—N1—C1—C40.0C2—N2—C3—C40.000 (1)
C3—N2—C2—O2180.0O3—C3—C4—C1180.0
C3—N2—C2—N10.0N2—C3—C4—C10.0
C1—N1—C2—O2180.0O1—C1—C4—C3180.0
C1—N1—C2—N20.0N1—C1—C4—C30.0
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (3)1.99 (3)2.767 (2)161 (3)
O4—H2O···O1ii0.85 (3)2.03 (3)2.863 (2)170 (3)
O5—H3O···O40.81 (4)1.93 (4)2.738 (2)178 (3)
O5—H4O···O10.80 (4)2.00 (4)2.783 (2)166 (3)
N1—H1N···O3iii0.82 (3)2.00 (3)2.817 (2)179 (2)
N2—H2N···O5iv0.92 (3)1.80 (3)2.721 (2)173 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(230) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.558 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 4267 reflections
a = 6.1739 (4) Åθ = 2.3–28.3°
b = 12.7594 (9) ŵ = 0.14 mm1
c = 8.8831 (6) ÅT = 230 K
V = 699.77 (8) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
923 independent reflections
Radiation source: sealed tube859 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
h = 88
Tmin = 0.778, Tmax = 0.979k = 1616
5804 measured reflectionsl = 1111
Refinement top
Refinement on F2Primary atom site location: using coordinates of another structure
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.043Hydrogen site location: difference Fourier map
wR(F2) = 0.112Only H-atom coordinates refined
S = 1.14 w = 1/[σ2(Fo2) + (0.0527P)2 + 0.2709P]
where P = (Fo2 + 2Fc2)/3
923 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.35 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C4H4N2O3·2H2OV = 699.77 (8) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.1739 (4) ŵ = 0.14 mm1
b = 12.7594 (9) ÅT = 230 K
c = 8.8831 (6) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
923 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
859 reflections with I > 2σ(I)
Tmin = 0.778, Tmax = 0.979Rint = 0.023
5804 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0430 restraints
wR(F2) = 0.112Only H-atom coordinates refined
S = 1.14Δρmax = 0.35 e Å3
923 reflectionsΔρmin = 0.20 e Å3
82 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55230 (10)0.47675 (15)0.0434 (4)
O20.25000.44187 (10)0.95832 (15)0.0410 (4)
O30.25000.79043 (10)0.88707 (17)0.0536 (5)
O40.25000.88647 (12)0.24022 (18)0.0483 (5)
H1O0.25000.915 (2)0.320 (4)0.058*
H2O0.25000.930 (2)0.171 (3)0.058*
O50.25000.67255 (13)0.21533 (17)0.0564 (6)
H3O0.25000.737 (3)0.225 (4)0.068*
H4O0.25000.647 (3)0.299 (4)0.068*
N10.25000.49881 (11)0.71743 (16)0.0299 (4)
H1N0.25000.436 (2)0.689 (3)0.036*
N20.25000.61718 (11)0.91939 (16)0.0290 (4)
H2N0.25000.6304 (19)1.018 (3)0.035*
C10.25000.57501 (13)0.61023 (19)0.0273 (4)
C20.25000.51527 (13)0.87125 (19)0.0274 (4)
C30.25000.70409 (13)0.8297 (2)0.0305 (4)
C40.25000.68701 (13)0.6624 (2)0.0291 (4)
H10.128 (3)0.7175 (11)0.6207 (18)0.035*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0858 (12)0.0263 (7)0.0180 (6)0.0000.0000.0005 (5)
O20.0812 (11)0.0192 (6)0.0225 (7)0.0000.0000.0046 (5)
O30.1174 (16)0.0168 (6)0.0265 (7)0.0000.0000.0009 (5)
O40.0949 (14)0.0263 (7)0.0238 (7)0.0000.0000.0016 (6)
O50.1217 (18)0.0283 (7)0.0193 (7)0.0000.0000.0003 (6)
N10.0558 (10)0.0138 (6)0.0201 (7)0.0000.0000.0014 (5)
N20.0529 (10)0.0173 (7)0.0168 (7)0.0000.0000.0003 (5)
C10.0432 (10)0.0194 (7)0.0194 (8)0.0000.0000.0011 (6)
C20.0441 (10)0.0178 (8)0.0204 (8)0.0000.0000.0006 (6)
C30.0522 (11)0.0167 (7)0.0225 (8)0.0000.0000.0015 (6)
C40.0497 (11)0.0168 (7)0.0208 (8)0.0000.0000.0030 (6)
Geometric parameters (Å, º) top
O1—C11.221 (2)N1—C11.361 (2)
O2—C21.215 (2)N1—C21.382 (2)
O3—C31.214 (2)N2—H2N0.89 (3)
O4—H1O0.79 (3)N2—C21.369 (2)
O4—H2O0.83 (3)N2—C31.366 (2)
O5—H3O0.82 (4)C1—C41.502 (2)
O5—H4O0.82 (4)C3—C41.502 (2)
N1—H1N0.84 (3)C4—H10.926 (16)
H1O—O4—H2O111 (3)N1—C1—C4117.61 (15)
H3O—O5—H4O108 (3)O2—C2—N1120.82 (16)
H1N—N1—C1118.2 (16)O2—C2—N2122.24 (16)
H1N—N1—C2116.1 (16)N1—C2—N2116.94 (15)
C1—N1—C2125.67 (15)O3—C3—N2119.48 (17)
H2N—N2—C2119.1 (16)O3—C3—C4123.18 (16)
H2N—N2—C3114.8 (16)N2—C3—C4117.35 (14)
C2—N2—C3126.10 (15)C1—C4—C3116.33 (14)
O1—C1—N1120.68 (16)C1—C4—H1106.0 (9)
O1—C1—C4121.71 (15)C3—C4—H1109.6 (10)
C2—N1—C1—O1180.0C2—N2—C3—O3180.0
C2—N1—C1—C40.0C2—N2—C3—C40.000 (1)
C3—N2—C2—O2180.0O3—C3—C4—C1180.0
C3—N2—C2—N10.0N2—C3—C4—C10.0
C1—N1—C2—O2180.0O1—C1—C4—C3180.0
C1—N1—C2—N20.0N1—C1—C4—C30.0
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.79 (3)2.00 (3)2.770 (2)163 (3)
O4—H2O···O1ii0.83 (3)2.04 (3)2.862 (2)171 (3)
O5—H3O···O40.82 (4)1.92 (4)2.738 (2)178 (3)
O5—H4O···O10.82 (4)1.99 (4)2.783 (2)166 (3)
N1—H1N···O3iii0.84 (3)1.98 (3)2.816 (2)177 (2)
N2—H2N···O5iv0.89 (3)1.84 (3)2.722 (2)174 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
(270) top
Crystal data top
C4H4N2O3·2H2OF(000) = 344
Mr = 164.12Dx = 1.549 Mg m3
Orthorhombic, PmnbMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2bc 2aCell parameters from 3968 reflections
a = 6.2144 (7) Åθ = 2.2–28.2°
b = 12.7512 (14) ŵ = 0.14 mm1
c = 8.8841 (10) ÅT = 270 K
V = 703.99 (14) Å3Block, colourless
Z = 40.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
940 independent reflections
Radiation source: sealed tube820 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.023
thin–slice ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
h = 88
Tmin = 0.797, Tmax = 0.979k = 1616
5918 measured reflectionsl = 1111
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Only H-atom coordinates refined
wR(F2) = 0.116 w = 1/[σ2(Fo2) + (0.0639P)2 + 0.1693P]
where P = (Fo2 + 2Fc2)/3
S = 1.11(Δ/σ)max < 0.001
940 reflectionsΔρmax = 0.24 e Å3
83 parametersΔρmin = 0.29 e Å3
0 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: using coordinates of another structureExtinction coefficient: 0.040 (7)
Crystal data top
C4H4N2O3·2H2OV = 703.99 (14) Å3
Mr = 164.12Z = 4
Orthorhombic, PmnbMo Kα radiation
a = 6.2144 (7) ŵ = 0.14 mm1
b = 12.7512 (14) ÅT = 270 K
c = 8.8841 (10) Å0.53 × 0.42 × 0.15 mm
Data collection top
Bruker SMART 1K CCD
diffractometer
940 independent reflections
Absorption correction: multi-scan
SADABS; Sheldrick (2003)
820 reflections with I > 2σ(I)
Tmin = 0.797, Tmax = 0.979Rint = 0.023
5918 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0410 restraints
wR(F2) = 0.116Only H-atom coordinates refined
S = 1.11Δρmax = 0.24 e Å3
940 reflectionsΔρmin = 0.29 e Å3
83 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.25000.55220 (10)0.47730 (15)0.0518 (5)
O20.25000.44201 (9)0.95826 (15)0.0484 (4)
O30.25000.79018 (10)0.88679 (16)0.0632 (6)
O40.25000.88616 (12)0.24031 (18)0.0582 (5)
H1O0.25000.916 (2)0.320 (4)0.070*
H2O0.25000.926 (2)0.174 (3)0.070*
O50.25000.67234 (13)0.21568 (16)0.0664 (6)
H3O0.25000.736 (3)0.224 (4)0.080*
H4O0.25000.646 (3)0.301 (4)0.080*
N10.25000.49881 (11)0.71776 (15)0.0358 (4)
H1N0.25000.437 (2)0.689 (3)0.043*
N20.25000.61715 (11)0.91930 (15)0.0343 (4)
H2N0.25000.6303 (19)1.018 (3)0.041*
C10.25000.57485 (13)0.61060 (18)0.0331 (4)
C20.25000.51514 (12)0.87106 (18)0.0325 (4)
C30.25000.70391 (12)0.8297 (2)0.0363 (4)
C40.25000.68682 (12)0.66246 (19)0.0348 (4)
H10.129 (3)0.7188 (11)0.6226 (17)0.042*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.1011 (12)0.0322 (7)0.0221 (6)0.0000.0000.0012 (5)
O20.0948 (12)0.0239 (6)0.0266 (7)0.0000.0000.0061 (5)
O30.1365 (16)0.0208 (6)0.0323 (7)0.0000.0000.0010 (5)
O40.1134 (14)0.0326 (7)0.0287 (7)0.0000.0000.0014 (5)
O50.1405 (18)0.0348 (7)0.0239 (7)0.0000.0000.0004 (5)
N10.0653 (10)0.0178 (6)0.0242 (7)0.0000.0000.0011 (5)
N20.0616 (10)0.0211 (7)0.0201 (6)0.0000.0000.0004 (5)
C10.0520 (10)0.0243 (7)0.0230 (8)0.0000.0000.0014 (6)
C20.0516 (10)0.0216 (7)0.0242 (8)0.0000.0000.0014 (6)
C30.0621 (11)0.0195 (7)0.0274 (8)0.0000.0000.0015 (6)
C40.0588 (11)0.0203 (7)0.0252 (8)0.0000.0000.0039 (6)
Geometric parameters (Å, º) top
O1—C11.219 (2)N1—C11.359 (2)
O2—C21.212 (2)N1—C21.378 (2)
O3—C31.211 (2)N2—H2N0.90 (2)
O4—H1O0.80 (3)N2—C21.369 (2)
O4—H2O0.78 (3)N2—C31.363 (2)
O5—H3O0.82 (4)C1—C41.500 (2)
O5—H4O0.83 (4)C3—C41.502 (2)
N1—H1N0.83 (3)C4—H10.927 (15)
H1O—O4—H2O111 (3)N1—C1—C4117.64 (14)
H3O—O5—H4O109 (3)O2—C2—N1121.02 (15)
H1N—N1—C1117.6 (16)O2—C2—N2122.04 (16)
H1N—N1—C2116.6 (16)N1—C2—N2116.93 (14)
C1—N1—C2125.78 (14)O3—C3—N2119.52 (16)
H2N—N2—C2119.0 (15)O3—C3—C4123.09 (15)
H2N—N2—C3114.9 (15)N2—C3—C4117.39 (14)
C2—N2—C3126.03 (14)C1—C4—C3116.23 (13)
O1—C1—N1120.77 (16)C1—C4—H1107.5 (9)
O1—C1—C4121.59 (15)C3—C4—H1108.3 (9)
C2—N1—C1—O1180.0C2—N2—C3—O3180.0
C2—N1—C1—C40.0C2—N2—C3—C40.0
C3—N2—C2—O2180.0O1—C1—C4—C3180.0
C3—N2—C2—N10.0N1—C1—C4—C30.0
C1—N1—C2—O2180.0O3—C3—C4—C1180.0
C1—N1—C2—N20.0N2—C3—C4—C10.0
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.80 (3)2.00 (3)2.771 (2)162 (3)
O4—H2O···O1ii0.78 (3)2.09 (3)2.867 (2)171 (3)
O5—H3O···O40.82 (4)1.92 (4)2.735 (2)179 (3)
O5—H4O···O10.83 (4)1.97 (4)2.784 (2)167 (3)
N1—H1N···O3iii0.83 (3)1.99 (3)2.818 (2)178 (2)
N2—H2N···O5iv0.90 (2)1.83 (3)2.725 (2)174 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.

Experimental details

(100)(150)(170)(190)
Crystal data
Chemical formulaC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2O
Mr164.12164.12164.12164.12
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21/nMonoclinic, P21/nMonoclinic, P21/n
Temperature (K)100150170190
a, b, c (Å)6.0970 (5), 12.7152 (10), 8.8587 (7)6.1130 (8), 12.7149 (16), 8.8564 (11)6.1270 (5), 12.7253 (11), 8.8633 (8)6.1377 (5), 12.7306 (11), 8.8641 (8)
α, β, γ (°)90, 94.0510 (14), 9090, 93.437 (2), 9090, 93.0680 (16), 9090, 92.5280 (15), 90
V3)685.05 (9)687.14 (15)690.06 (10)691.94 (10)
Z4444
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.150.150.150.15
Crystal size (mm)0.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.15
Data collection
DiffractometerBruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Absorption correctionMulti-scan
TWINABS; (Sheldrick, 2002)
Multi-scan
TWINABS; Sheldrick (2002)
Multi-scan
TWINABS; Sheldrick (2002)
Multi-scan
TWINABS; Sheldrick (2002)
Tmin, Tmax0.861, 0.9780.861, 0.9780.823, 0.9780.782, 0.978
No. of measured, independent and
observed [I > 2σ(I)] reflections
9480, 2263, 2126 8078, 2212, 2148 9428, 2124, 2011 9902, 2140, 1930
Rint0.0190.0290.0240.024
(sin θ/λ)max1)0.6660.6660.6680.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.032, 0.085, 1.11 0.051, 0.132, 1.26 0.040, 0.105, 1.16 0.037, 0.105, 1.06
No. of reflections2263221221242140
No. of parameters120120120120
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.32, 0.300.38, 0.340.30, 0.330.26, 0.28


(200)(210)(215)(216)
Crystal data
Chemical formulaC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2O
Mr164.12164.12164.12164.12
Crystal system, space groupMonoclinic, P21/nMonoclinic, P21/nMonoclinic, P21/nMonoclinic, P21/n
Temperature (K)200210215216
a, b, c (Å)6.1313 (12), 12.703 (2), 8.8456 (17)6.1538 (15), 12.747 (3), 8.877 (2)6.1580 (9), 12.7515 (18), 8.8763 (13)6.1567 (16), 12.733 (3), 8.865 (2)
α, β, γ (°)90, 92.187 (4), 9090, 91.627 (4), 9090, 91.263 (3), 9090, 91.180 (5), 90
V3)688.5 (2)696.0 (3)696.83 (17)694.8 (3)
Z4444
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.150.150.150.15
Crystal size (mm)0.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.15
Data collection
DiffractometerBruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Absorption correctionMulti-scan
TWINABS; Sheldrick (2002)
Multi-scan
TWINABS; Sheldrick (2002)
Multi-scan
TWINABS; Sheldrick (2002)
Multi-scan
TWINABS; Sheldrick (2002)
Tmin, Tmax0.553, 0.9780.574, 0.9790.331, 0.9790.492, 0.979
No. of measured, independent and
observed [I > 2σ(I)] reflections
7874, 2456, 2397 7495, 2165, 2018 8726, 2442, 2299 7321, 2209, 2058
Rint0.0290.0270.0260.024
(sin θ/λ)max1)0.6660.6670.6670.677
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.087, 0.197, 1.31 0.066, 0.152, 1.28 0.069, 0.194, 1.19 0.068, 0.181, 1.30
No. of reflections2456216524422209
No. of parameters120120120120
H-atom treatmentH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinementH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.50, 0.580.42, 0.420.41, 0.440.33, 0.47


(217)(218)(219)(220)
Crystal data
Chemical formulaC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2OC4H4N2O3·2H2O
Mr164.12164.12164.12164.12
Crystal system, space groupOrthorhombic, PmnbOrthorhombic, PmnbOrthorhombic, PmnbOrthorhombic, Pmnb
Temperature (K)217218219220
a, b, c (Å)6.1770 (18), 12.785 (4), 8.898 (3)6.1626 (19), 12.757 (4), 8.876 (3)6.1624 (15), 12.757 (3), 8.878 (2)6.1665 (12), 12.763 (2), 8.8814 (17)
α, β, γ (°)90, 90, 9090, 90, 9090, 90, 9090, 90, 90
V3)702.7 (3)697.8 (4)697.9 (3)699.0 (2)
Z4444
Radiation typeMo KαMo KαMo KαMo Kα
µ (mm1)0.140.150.150.15
Crystal size (mm)0.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.150.53 × 0.42 × 0.15
Data collection
DiffractometerBruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Absorption correctionMulti-scan
SADABS; Sheldrick (2003)
Multi-scan
SADABS; Sheldrick (2003)
Multi-scan
SADBAS; Sheldrick (2003)
Multi-scan
SADABS; Sheldrick (2003)
Tmin, Tmax0.321, 0.9790.351, 0.9790.353, 0.9790.452, 0.979
No. of measured, independent and
observed [I > 2σ(I)] reflections
5924, 889, 800 5224, 904, 829 5236, 914, 865 5578, 923, 824
Rint0.0500.0470.0460.043
(sin θ/λ)max1)0.6690.6660.6670.669
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.061, 0.154, 1.25 0.054, 0.137, 1.17 0.066, 0.158, 1.32 0.045, 0.124, 1.09
No. of reflections889904914923
No. of parameters82828282
H-atom treatmentOnly H-atom coordinates refinedOnly H-atom coordinates refinedOnly H-atom coordinates refinedOnly H-atom coordinates refined
Δρmax, Δρmin (e Å3)0.35, 0.280.29, 0.280.32, 0.330.26, 0.28


(230)(270)
Crystal data
Chemical formulaC4H4N2O3·2H2OC4H4N2O3·2H2O
Mr164.12164.12
Crystal system, space groupOrthorhombic, PmnbOrthorhombic, Pmnb
Temperature (K)230270
a, b, c (Å)6.1739 (4), 12.7594 (9), 8.8831 (6)6.2144 (7), 12.7512 (14), 8.8841 (10)
α, β, γ (°)90, 90, 9090, 90, 90
V3)699.77 (8)703.99 (14)
Z44
Radiation typeMo KαMo Kα
µ (mm1)0.140.14
Crystal size (mm)0.53 × 0.42 × 0.150.53 × 0.42 × 0.15
Data collection
DiffractometerBruker SMART 1K CCD
diffractometer
Bruker SMART 1K CCD
diffractometer
Absorption correctionMulti-scan
SADABS; Sheldrick (2003)
Multi-scan
SADABS; Sheldrick (2003)
Tmin, Tmax0.778, 0.9790.797, 0.979
No. of measured, independent and
observed [I > 2σ(I)] reflections
5804, 923, 859 5918, 940, 820
Rint0.0230.023
(sin θ/λ)max1)0.6670.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.112, 1.14 0.041, 0.116, 1.11
No. of reflections923940
No. of parameters8283
H-atom treatmentOnly H-atom coordinates refinedOnly H-atom coordinates refined
Δρmax, Δρmin (e Å3)0.35, 0.200.24, 0.29

Computer programs: Bruker SMART, Bruker SAINT, SHELXS97 (Sheldrick, 1990), by using coordinates of another structure, using coordinates of 150K structure, SHELXL97 (Sheldrick, 1997), Bruker SHELXTL and local programs.

Hydrogen-bond geometry (Å, º) for (100) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.819 (17)1.969 (17)2.7583 (11)161.9 (16)
O4—H2O···O1ii0.822 (17)2.034 (17)2.8508 (11)172.4 (15)
O5—H3O···O40.821 (18)1.931 (19)2.7463 (12)171.7 (17)
O5—H4O···O10.828 (17)1.967 (18)2.7819 (12)167.9 (16)
N1—H1N···O3iii0.823 (15)1.986 (16)2.8084 (12)177.2 (14)
N2—H2N···O5iv0.874 (15)1.861 (15)2.7277 (12)171.2 (14)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (150) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (3)1.98 (3)2.759 (2)161 (3)
O4—H2O···O1ii0.83 (3)2.03 (3)2.850 (2)171 (3)
O5—H3O···O40.79 (3)1.96 (3)2.743 (2)173 (4)
O5—H4O···O10.81 (3)1.99 (3)2.781 (2)165 (3)
N1—H1N···O3iii0.82 (3)2.00 (3)2.814 (2)175 (3)
N2—H2N···O5iv0.85 (3)1.88 (3)2.721 (2)173 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (170) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (2)1.97 (2)2.7611 (14)161 (2)
O4—H2O···O1ii0.82 (2)2.04 (2)2.8546 (14)171 (2)
O5—H3O···O40.83 (2)1.91 (2)2.7397 (16)174 (2)
O5—H4O···O10.82 (2)1.97 (2)2.7797 (15)167 (2)
N1—H1N···O3iii0.838 (18)1.975 (18)2.8117 (15)176.5 (16)
N2—H2N···O5iv0.858 (18)1.870 (18)2.7224 (14)172.3 (17)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (190) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.852 (18)1.941 (19)2.7606 (13)161.1 (17)
O4—H2O···O1ii0.827 (19)2.037 (19)2.8567 (12)170.7 (17)
O5—H3O···O40.82 (2)1.92 (2)2.7384 (14)175 (2)
O5—H4O···O10.84 (2)1.96 (2)2.7785 (13)167.3 (18)
N1—H1N···O3iii0.835 (16)1.976 (16)2.8103 (13)176.8 (14)
N2—H2N···O5iv0.870 (16)1.854 (16)2.7204 (13)173.7 (15)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (200) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.85 (5)1.96 (5)2.755 (3)155 (4)
O4—H2O···O1ii0.80 (5)2.05 (5)2.848 (3)173 (5)
O5—H3O···O40.78 (5)1.96 (5)2.733 (3)170 (6)
O5—H4O···O10.79 (5)2.00 (5)2.772 (3)165 (5)
N1—H1N···O3iii0.80 (4)2.01 (4)2.813 (3)175 (4)
N2—H2N···O5iv0.85 (4)1.87 (4)2.714 (3)174 (4)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (210) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (4)2.00 (4)2.767 (3)157 (3)
O4—H2O···O1ii0.83 (4)2.04 (4)2.861 (3)169 (4)
O5—H3O···O40.80 (4)1.94 (4)2.739 (3)174 (5)
O5—H4O···O10.79 (4)2.01 (4)2.782 (3)166 (4)
N1—H1N···O3iii0.84 (3)1.98 (3)2.815 (3)176 (3)
N2—H2N···O5iv0.83 (3)1.90 (3)2.724 (3)173 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (215) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.86 (4)1.95 (4)2.763 (2)159 (3)
O4—H2O···O1ii0.85 (4)2.02 (4)2.860 (2)169 (3)
O5—H3O···O40.83 (4)1.91 (4)2.740 (3)179 (4)
O5—H4O···O10.82 (4)1.98 (4)2.778 (2)166 (4)
N1—H1N···O3iii0.83 (3)1.99 (3)2.816 (2)177 (3)
N2—H2N···O5iv0.83 (3)1.89 (3)2.722 (2)173 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (216) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.85 (4)1.95 (4)2.763 (3)161 (3)
O4—H2O···O1ii0.83 (4)2.05 (4)2.854 (3)163 (4)
O5—H3O···O40.78 (4)1.98 (4)2.735 (3)165 (5)
O5—H4O···O10.82 (4)1.98 (4)2.775 (3)160 (4)
N1—H1N···O3iii0.81 (3)2.01 (3)2.815 (3)176 (4)
N2—H2N···O5iv0.87 (3)1.86 (3)2.719 (3)170 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (217) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.84 (5)1.95 (5)2.771 (3)166 (4)
O4—H2O···O1ii0.83 (5)2.05 (5)2.867 (3)169 (4)
O5—H3O···O40.82 (5)1.92 (6)2.744 (3)178 (5)
O5—H4O···O10.77 (5)2.04 (5)2.788 (3)163 (5)
N1—H1N···O3iii0.81 (4)2.01 (4)2.824 (3)178 (3)
N2—H2N···O5iv0.92 (4)1.81 (4)2.726 (3)172 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (218) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (4)1.96 (4)2.764 (3)162 (4)
O4—H2O···O1ii0.85 (4)2.03 (4)2.861 (3)168 (4)
O5—H3O···O40.80 (5)1.94 (5)2.738 (3)179 (4)
O5—H4O···O10.79 (4)2.01 (5)2.780 (3)166 (4)
N1—H1N···O3iii0.82 (3)2.00 (3)2.817 (3)178 (3)
N2—H2N···O5iv0.92 (3)1.81 (3)2.720 (3)171 (3)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (219) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.83 (5)1.97 (5)2.767 (3)162 (5)
O4—H2O···O1ii0.89 (5)1.98 (5)2.860 (3)170 (4)
O5—H3O···O40.76 (6)1.98 (6)2.741 (4)179 (6)
O5—H4O···O10.79 (6)2.02 (6)2.781 (3)164 (5)
N1—H1N···O3iii0.82 (4)2.00 (4)2.818 (3)178 (4)
N2—H2N···O5iv0.88 (4)1.84 (4)2.720 (3)172 (4)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (220) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.81 (3)1.99 (3)2.767 (2)161 (3)
O4—H2O···O1ii0.85 (3)2.03 (3)2.863 (2)170 (3)
O5—H3O···O40.81 (4)1.93 (4)2.738 (2)178 (3)
O5—H4O···O10.80 (4)2.00 (4)2.783 (2)166 (3)
N1—H1N···O3iii0.82 (3)2.00 (3)2.817 (2)179 (2)
N2—H2N···O5iv0.92 (3)1.80 (3)2.721 (2)173 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (230) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.79 (3)2.00 (3)2.770 (2)163 (3)
O4—H2O···O1ii0.83 (3)2.04 (3)2.862 (2)171 (3)
O5—H3O···O40.82 (4)1.92 (4)2.738 (2)178 (3)
O5—H4O···O10.82 (4)1.99 (4)2.783 (2)166 (3)
N1—H1N···O3iii0.84 (3)1.98 (3)2.816 (2)177 (2)
N2—H2N···O5iv0.89 (3)1.84 (3)2.722 (2)174 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
Hydrogen-bond geometry (Å, º) for (270) top
D—H···AD—HH···AD···AD—H···A
O4—H1O···O2i0.80 (3)2.00 (3)2.771 (2)162 (3)
O4—H2O···O1ii0.78 (3)2.09 (3)2.867 (2)171 (3)
O5—H3O···O40.82 (4)1.92 (4)2.735 (2)179 (3)
O5—H4O···O10.83 (4)1.97 (4)2.784 (2)167 (3)
N1—H1N···O3iii0.83 (3)1.99 (3)2.818 (2)178 (2)
N2—H2N···O5iv0.90 (2)1.83 (3)2.725 (2)174 (2)
Symmetry codes: (i) x+1/2, y+1/2, z+3/2; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+3/2; (iv) x, y, z+1.
 

Footnotes

1Supplementary data for this paper are available from the IUCr electronic archives (Reference: WS5026 ). Services for accessing these data are described at the back of the journal.

Acknowledgements

We thank Dr Neil Brooks and Dr Ross Harrington, Newcastle University, for advice related to twinning and for experimental assistance, the EPSRC for financial support, and Professor Sally Price, University College London, for helpful discussions and pre-publication results relating to polymorph prediction for barbituric acid.

References

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