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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 66| Part 8| August 2010| Page o1946
https://doi.org/10.1107/S160053681002581X

Guanidinium 3-nitro­benzoate

Graham Smitha* and Urs D. Wermuthb

aFaculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia, and bSchool of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland 4111, Australia
*Correspondence e-mail: g.smith@qut.edu.au

(Received 25 May 2010; accepted 1 July 2010; online 7 July 2010)

The title compound, CH6N3+·C7H4NO4−, an anhydrous guanidinium salt, shows a N—H⋯O hydrogen-bond network in which the guanidinium cation is involved in three cyclic R21(6) hydrogen-bonding associations with separate carboxyl­ate O-atom acceptors. Further peripheral associations include a cyclic R12(4) cation–anion inter­action, forming inter­linked undulating sheets in the three-dimensional structure.

Related literature

For the structures of other guanidinium benzoate salts, see: Kleb et al. (1998[Kleb, D.-C., Schürmann, M., Preut, H. & Bleckmann, P. (1998). Z. Kristallogr. New Cryst. Struct. 213, 581-582.]); Pereira Silva et al. (2007[Pereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2007). Acta Cryst. E63, o2783.], 2010[Pereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2010). Acta Cryst. E66, o524.]). For graph-set analysis, see: Etter et al. (1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]).

[Scheme 1]

Experimental

Crystal data

  • CH6N3+·C7H4NO4−

  • Mr = 226.20

  • Orthorhombic, P 21 21 21

  • a = 7.3978 (12) Å

  • b = 10.1302 (12) Å

  • c = 13.7118 (17) Å

  • V = 1027.6 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 297 K

  • 0.30 × 0.30 × 0.20 mm
Data collection

  • Oxford Diffraction Gemini-S CCD-detector diffractometer

  • Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]) Tmin = 0.94, Tmax = 0.98

  • 7455 measured reflections

  • 1252 independent reflections

  • 1092 reflections with I > 2σ(I)

  • Rint = 0.030
Refinement

  • R[F2 > 2σ(F2)] = 0.035

  • wR(F2) = 0.096

  • S = 1.03

  • 1252 reflections

  • 169 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.15 e Å−3

  • Δρmin = −0.16 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1G—H11G⋯O12 0.82 (3) 2.48 (3) 3.161 (3) 142 (3)
N1G—H12G⋯O12i 0.83 (3) 2.09 (3) 2.887 (3) 162 (3)
N2G—H21G⋯O11i 0.91 (3) 2.42 (3) 3.292 (3) 160 (2)
N2G—H21G⋯O12i 0.91 (3) 2.43 (3) 3.159 (3) 137 (2)
N2G—H22G⋯O11ii 0.86 (3) 2.29 (3) 3.020 (3) 143 (3)
N3G—H31G⋯O11ii 0.86 (3) 1.97 (3) 2.783 (3) 157 (3)
N3G—H32G⋯O12 0.91 (3) 1.90 (3) 2.794 (3) 166 (3)
Symmetry codes: (i) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, -z]; (ii) [-x+{\script{3\over 2}}, -y+1, z+{\script{1\over 2}}].

Data collection: CrysAlis PRO (Oxford Diffraction, 2009[Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) within WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]); molecular graphics: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: PLATON.

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S160053681002581X/bv2146sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681002581X/bv2146Isup2.hkl

checkCIF report


Comment top

The structures of the guanidinium salts of the simple benzoic acids are not numerous in the crystallographic literature, being limited to the benzoate (Pereira Silva et al., 2007), 4-aminobenzoate (Pereira Silva et al., 2010) and 4-nitrobenzoate (Kleb et al., 1998). In these anhydrous structures and those of the anhydrous guanidinium salts of aromatic carboxylates generally, the cations give variously cyclic hydrogen-bonding interactions which may be classified by the graph sets R22(8), R12(4) or R21(6) (Etter et al., 1990). Our 1:1 stoichiometric reaction of 3-nitrobenzoic acid with guanidinium carbonate in methanol gave large relatively hard, chemically stable crystals of guanidinium 3-nitrobenzoate, CH6N3+ C7H4NO4- (I), and the structure is reported here.

In the structure of (I) each guanidinium cation is involved in three cyclic R21(6) hydrogen-bonding associations (Table 1) with separate carboxylate O-acceptors (Figs. 1, 2). Further peripheral associations include a cyclic R12(4) cation–anion interaction, form inter-linked undulating sheets which give a three-dimensional framework structure (Fig. 3).

The carboxylate group of the anion is rotated slightly out of the plane of the benzene ring [torsion angle C2–C1–C11–O11, 160.0 (2)°]. However, the unassociated nitro group is essentially coplanar with the ring [torsion angle C2–C3–N31–O32, 174.4 (2)°].

Related literature top

For the structures of other guanidinium benzoate salts, see: Kleb et al. (1998); Pereira Silva et al. (2007, 2010). For graph-set analysis, see: Etter et al. (1990).

For related literature, see: Sheldrick (1996).

Experimental top

The title compound was synthesized by heating together under reflux for 10 minutes 1 mmol of 3-nitrobenzoic acid and 0.5 mmol of guanidine carbonate in 50 ml of methanol. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave large colourless plates (m.p. 514 K) from which a suitable analytical specimen was cleaved.

Refinement top

Guanidinium hydrogen atoms were located by difference methods and their positional and isotropic displacement parameters were refined. The H atoms of the aromatic ring of the anion were included in the refinement in calculated positions (C–H = 0.93 Å) and allowed to ride, with Uiso(H) = 1.2Ueq(C). Friedel pairs were merged in the data set used for final structure refinement.

Structure description top

The structures of the guanidinium salts of the simple benzoic acids are not numerous in the crystallographic literature, being limited to the benzoate (Pereira Silva et al., 2007), 4-aminobenzoate (Pereira Silva et al., 2010) and 4-nitrobenzoate (Kleb et al., 1998). In these anhydrous structures and those of the anhydrous guanidinium salts of aromatic carboxylates generally, the cations give variously cyclic hydrogen-bonding interactions which may be classified by the graph sets R22(8), R12(4) or R21(6) (Etter et al., 1990). Our 1:1 stoichiometric reaction of 3-nitrobenzoic acid with guanidinium carbonate in methanol gave large relatively hard, chemically stable crystals of guanidinium 3-nitrobenzoate, CH6N3+ C7H4NO4- (I), and the structure is reported here.

In the structure of (I) each guanidinium cation is involved in three cyclic R21(6) hydrogen-bonding associations (Table 1) with separate carboxylate O-acceptors (Figs. 1, 2). Further peripheral associations include a cyclic R12(4) cation–anion interaction, form inter-linked undulating sheets which give a three-dimensional framework structure (Fig. 3).

The carboxylate group of the anion is rotated slightly out of the plane of the benzene ring [torsion angle C2–C1–C11–O11, 160.0 (2)°]. However, the unassociated nitro group is essentially coplanar with the ring [torsion angle C2–C3–N31–O32, 174.4 (2)°].

For the structures of other guanidinium benzoate salts, see: Kleb et al. (1998); Pereira Silva et al. (2007, 2010). For graph-set analysis, see: Etter et al. (1990).

For related literature, see: Sheldrick (1996).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular configuration and atom-numbering scheme for the cation and anion species in (I). Non-H atoms are shown as 40% probability ellipsoids. Inter-ion hydrogen bonds are shown as dashed lines.
[Figure 2] Fig. 2. Peripheral hydrogen-bonding extension of the R21(6)- associated guanidinium-tris(3-nitrobenzoate) structures of (I), viewed down the a cell direction. For symmetry codes, see Table 1. Hydrogen bonds are shown as dashed lines.
[Figure 3] Fig. 3. The three-dimensional structure of (I) viewed down the approximate b cell direction. Non-associative H atoms are omitted.
Guanidinium 3-nitrobenzoate top
Crystal data top
CH6N3+·C7H4NO4−Dx = 1.462 Mg m−3
Mr = 226.20Melting point: 514 K
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 2964 reflections
a = 7.3978 (12) Åθ = 3.0–28.9°
b = 10.1302 (12) ŵ = 0.12 mm−1
c = 13.7118 (17) ÅT = 297 K
V = 1027.6 (2) Å3Block, colourless
Z = 40.30 × 0.30 × 0.20 mm
F(000) = 472
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer		1252 independent reflections
Radiation source: Enhance (Mo) X-ray source1092 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.030
ω scansθmax = 26.5°, θmin = 3.0°
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2009)		h = −9→9
Tmin = 0.94, Tmax = 0.98k = −12→11
7455 measured reflectionsl = −17→17
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)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.096H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0716P)2]
where P = (Fo2 + 2Fc2)/3
1252 reflections(Δ/σ)max < 0.001
169 parametersΔρmax = 0.15 e Å−3
0 restraintsΔρmin = −0.16 e Å−3
Crystal data top
CH6N3+·C7H4NO4−V = 1027.6 (2) Å3
Mr = 226.20Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 7.3978 (12) ŵ = 0.12 mm−1
b = 10.1302 (12) ÅT = 297 K
c = 13.7118 (17) Å0.30 × 0.30 × 0.20 mm
Data collection top
Oxford Diffraction Gemini-S CCD-detector
diffractometer		1252 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Oxford Diffraction, 2009)		1092 reflections with I > 2σ(I)
Tmin = 0.94, Tmax = 0.98Rint = 0.030
7455 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.096H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.15 e Å−3
1252 reflectionsΔρmin = −0.16 e Å−3
169 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O110.8853 (3)0.39642 (19)−0.15616 (11)0.0763 (7)
O120.8391 (3)0.51830 (14)−0.02410 (12)0.0587 (5)
O310.9478 (4)0.2929 (2)0.29189 (13)0.0891 (8)
O320.8919 (4)0.0871 (2)0.30563 (13)0.0879 (8)
N310.9085 (3)0.1871 (2)0.25680 (14)0.0582 (6)
C10.8552 (3)0.28643 (18)−0.00456 (13)0.0395 (5)
C20.8834 (3)0.29418 (19)0.09621 (14)0.0395 (5)
C30.8802 (3)0.1785 (2)0.15053 (15)0.0438 (6)
C40.8496 (3)0.0567 (2)0.10846 (18)0.0546 (7)
C50.8224 (3)0.0507 (2)0.00897 (18)0.0579 (8)
C60.8262 (3)0.1633 (2)−0.04688 (16)0.0487 (6)
C110.8592 (3)0.4098 (2)−0.06632 (14)0.0472 (6)
N1G0.5698 (4)0.7518 (2)0.02372 (14)0.0596 (7)
N2G0.5023 (3)0.7924 (2)0.18458 (16)0.0624 (7)
N3G0.6559 (3)0.6050 (2)0.14213 (17)0.0599 (7)
C1G0.5763 (3)0.7166 (2)0.11723 (14)0.0468 (6)
H20.903900.375200.126200.0470*
H40.84730−0.019500.146300.0660*
H50.80130−0.03050−0.020600.0690*
H60.809200.15720−0.113900.0580*
H11G0.617 (4)0.701 (3)−0.015 (2)0.070 (9)*
H12G0.514 (4)0.821 (3)0.012 (2)0.072 (8)*
H21G0.444 (4)0.869 (3)0.170 (2)0.077 (9)*
H22G0.506 (4)0.767 (3)0.244 (2)0.065 (8)*
H31G0.666 (4)0.588 (3)0.203 (2)0.065 (8)*
H32G0.715 (4)0.563 (3)0.093 (2)0.073 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O110.1174 (16)0.0759 (12)0.0357 (8)0.0071 (13)0.0050 (10)0.0078 (8)
O120.0866 (12)0.0375 (7)0.0520 (8)−0.0007 (8)0.0034 (9)0.0074 (6)
O310.148 (2)0.0728 (12)0.0464 (9)−0.0228 (14)−0.0197 (12)0.0015 (9)
O320.1360 (19)0.0687 (11)0.0591 (11)0.0044 (13)0.0017 (12)0.0305 (9)
N310.0728 (11)0.0565 (11)0.0452 (10)0.0004 (11)−0.0036 (9)0.0113 (8)
C10.0411 (9)0.0384 (10)0.0390 (9)−0.0016 (9)0.0000 (9)−0.0014 (8)
C20.0476 (10)0.0313 (8)0.0395 (9)−0.0005 (9)−0.0007 (8)0.0007 (7)
C30.0486 (10)0.0413 (10)0.0415 (10)0.0011 (9)−0.0006 (9)0.0044 (8)
C40.0643 (13)0.0340 (10)0.0656 (13)−0.0007 (10)0.0029 (12)0.0083 (10)
C50.0679 (15)0.0348 (10)0.0710 (15)−0.0073 (10)0.0012 (13)−0.0151 (10)
C60.0527 (11)0.0490 (11)0.0445 (10)−0.0037 (10)0.0000 (9)−0.0100 (9)
C110.0597 (12)0.0444 (10)0.0375 (10)0.0004 (10)0.0016 (10)0.0038 (9)
N1G0.0873 (16)0.0448 (10)0.0467 (12)0.0052 (11)0.0022 (11)0.0093 (9)
N2G0.0885 (15)0.0519 (11)0.0469 (11)0.0123 (12)0.0033 (11)−0.0015 (9)
N3G0.0854 (14)0.0511 (11)0.0433 (10)0.0130 (12)0.0016 (11)0.0069 (9)
C1G0.0588 (12)0.0398 (10)0.0418 (11)−0.0032 (10)−0.0027 (9)0.0025 (9)
Geometric parameters (Å, º) top
O11—C111.254 (2)N3G—H32G0.91 (3)
O12—C111.251 (3)C1—C61.392 (3)
O31—N311.210 (3)C1—C111.510 (3)
O32—N311.221 (3)C1—C21.400 (3)
N31—C31.475 (3)C2—C31.389 (3)
N1G—C1G1.332 (3)C3—C41.381 (3)
N2G—C1G1.320 (3)C4—C51.380 (3)
N3G—C1G1.320 (3)C5—C61.374 (3)
N1G—H12G0.83 (3)C2—H20.9300
N1G—H11G0.82 (3)C4—H40.9300
N2G—H22G0.86 (3)C5—H50.9300
N2G—H21G0.91 (3)C6—H60.9300
N3G—H31G0.86 (3)
O31—N31—O32122.8 (2)C2—C3—C4122.2 (2)
O31—N31—C3118.64 (19)C3—C4—C5118.4 (2)
O32—N31—C3118.60 (19)C4—C5—C6120.8 (2)
C1G—N1G—H12G115.5 (19)C1—C6—C5121.0 (2)
H11G—N1G—H12G128 (3)O11—C11—C1117.67 (18)
C1G—N1G—H11G116 (2)O12—C11—C1117.73 (17)
H21G—N2G—H22G119 (3)O11—C11—O12124.6 (2)
C1G—N2G—H21G122.6 (18)C3—C2—H2121.00
C1G—N2G—H22G119 (2)C1—C2—H2121.00
H31G—N3G—H32G126 (3)C3—C4—H4121.00
C1G—N3G—H32G115.1 (19)C5—C4—H4121.00
C1G—N3G—H31G118 (2)C4—C5—H5120.00
C6—C1—C11120.72 (17)C6—C5—H5120.00
C2—C1—C11120.29 (17)C5—C6—H6120.00
C2—C1—C6118.99 (17)C1—C6—H6119.00
C1—C2—C3118.66 (18)N2G—C1G—N3G120.2 (2)
N31—C3—C4119.27 (19)N1G—C1G—N2G120.2 (2)
N31—C3—C2118.53 (18)N1G—C1G—N3G119.6 (2)
O31—N31—C3—C2−5.8 (3)C2—C1—C11—O12−18.9 (3)
O31—N31—C3—C4174.9 (2)C6—C1—C11—O11−19.1 (3)
O32—N31—C3—C2174.4 (2)C6—C1—C11—O12162.0 (2)
O32—N31—C3—C4−4.9 (3)C1—C2—C3—N31−179.5 (2)
C6—C1—C2—C3−0.4 (3)C1—C2—C3—C4−0.2 (3)
C11—C1—C2—C3−179.5 (2)N31—C3—C4—C5179.6 (2)
C2—C1—C6—C51.0 (3)C2—C3—C4—C50.4 (3)
C11—C1—C6—C5−180.0 (2)C3—C4—C5—C60.2 (3)
C2—C1—C11—O11160.0 (2)C4—C5—C6—C1−0.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1G—H11G···O120.82 (3)2.48 (3)3.161 (3)142 (3)
N1G—H12G···O12i0.83 (3)2.09 (3)2.887 (3)162 (3)
N2G—H21G···O11i0.91 (3)2.42 (3)3.292 (3)160 (2)
N2G—H21G···O12i0.91 (3)2.43 (3)3.159 (3)137 (2)
N2G—H22G···O11ii0.86 (3)2.29 (3)3.020 (3)143 (3)
N3G—H31G···O11ii0.86 (3)1.97 (3)2.783 (3)157 (3)
N3G—H32G···O120.91 (3)1.90 (3)2.794 (3)166 (3)
C4—H4···O31iii0.932.573.355 (3)142
Symmetry codes: (i) x−1/2, −y+3/2, −z; (ii) −x+3/2, −y+1, z+1/2; (iii) −x+2, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formulaCH6N3+·C7H4NO4−
Mr226.20
Crystal system, space groupOrthorhombic, P212121
Temperature (K)297
a, b, c (Å)7.3978 (12), 10.1302 (12), 13.7118 (17)
V (Å3)1027.6 (2)
Z4
Radiation typeMo Kα
µ (mm−1)0.12
Crystal size (mm)0.30 × 0.30 × 0.20
Data collection
DiffractometerOxford Diffraction Gemini-S CCD-detector
diffractometer
Absorption correctionMulti-scan
(CrysAlis PRO; Oxford Diffraction, 2009)
Tmin, Tmax0.94, 0.98
No. of measured, independent and
observed [I > 2σ(I)] reflections		7455, 1252, 1092
Rint0.030
(sin θ/λ)max (Å−1)0.628
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.096, 1.03
No. of reflections1252
No. of parameters169
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.15, −0.16

Computer programs: CrysAlis PRO (Oxford Diffraction, 2009), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 1999), PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1G—H11G···O120.82 (3)2.48 (3)3.161 (3)142 (3)
N1G—H12G···O12i0.83 (3)2.09 (3)2.887 (3)162 (3)
N2G—H21G···O11i0.91 (3)2.42 (3)3.292 (3)160 (2)
N2G—H21G···O12i0.91 (3)2.43 (3)3.159 (3)137 (2)
N2G—H22G···O11ii0.86 (3)2.29 (3)3.020 (3)143 (3)
N3G—H31G···O11ii0.86 (3)1.97 (3)2.783 (3)157 (3)
N3G—H32G···O120.91 (3)1.90 (3)2.794 (3)166 (3)
Symmetry codes: (i) x−1/2, −y+3/2, −z; (ii) −x+3/2, −y+1, z+1/2.
 

Acknowledgements

The authors acknowledge financial support from the Australian Research Council, the Faculty of Science and Technology, Queensland University of Technology and the School of Biomolecular and Physical Sciences, Griffith University.

References

First citationAltomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.  CrossRef Web of Science IUCr Journals Google Scholar
 First citationEtter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262.  CrossRef CAS Web of Science IUCr Journals Google Scholar
 First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
 First citationKleb, D.-C., Schürmann, M., Preut, H. & Bleckmann, P. (1998). Z. Kristallogr. New Cryst. Struct. 213, 581–582.  CAS Google Scholar
 First citationOxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, Oxfordshire, England.  Google Scholar
 First citationPereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2007). Acta Cryst. E63, o2783.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationPereira Silva, P. S., Ramos Silva, M., Paixão, J. A. & Matos Beja, A. (2010). Acta Cryst. E66, o524.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890
Volume 66| Part 8| August 2010| Page o1946
https://doi.org/10.1107/S160053681002581X
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