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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 68| Part 3| March 2012| Page o853
doi:10.1107/S1600536812006897

2-(3-Amino­pyridinium-1-yl)-3-carb­­oxy­propano­ate monohydrate

Guadalupe Millán Corrales,a David Morales-Morales,b Simón Hernández-Ortega,b José J. Campos-Gaxiolaa and Adriana Cruz Enríqueza*

aFacultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Fuente de Poseidón y Prol. Angel Flores, CP 81223, Los Mochis, Sinaloa, Mexico, and bInstituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacan, CP 04510, México, DF, Mexico
*Correspondence e-mail: cenriqueza@yahoo.com.mx

(Received 31 January 2012; accepted 15 February 2012; online 24 February 2012)

The title compound, C9H10N2O4·H2O, was obtained as a zwitterion derived from the nucleophilic attack of 3-amino­pyridine on the fumaric α,β-system. Within the molecule, the amino­pyridine moiety and the carboxyl­ate and carb­oxy­lic acid fragments form dihedral angles of 68.6 (2) and 62.8 (2)°, respectively. The geometry adopted by the mol­ecule does not allow the formation of centrosymmetric dimeric hydrogen-bonded units; instead chains along the a axis are linked by COO—H⋯OOC motifs. These chains are inter­connected by N—H⋯O and O—H⋯O hydrogen bonds involving the carb­oxy­lic acid and carboxyl­ate units and the solvent water mol­ecules.

Related literature

For background to the synthesis, see: Kavuru et al. (2010[Kavuru, P., Aboarayes, D., Arora, K. K., Clarke, H. D., Kennedy, A., Marshall, L., Ong, T. T., Perman, J., Pujari, T., Wojtas, L. & Zaworotko, M. J. (2010). Cryst. Growth Des. 10, 3568-3584.]). For structures and applications of zwitterion derivatives, see: Bis & Zaworotko (2005[Bis, J. A. & Zaworotko, M. J. (2005). Cryst. Growth Des. 5, 1169-1179.]); Hill et al. (2001[Hill, L. W., Rondan, N. & Schmidt, D. (2001). Macromolecules, 34, 372-375.]); Sarma et al. (2009[Sarma, B. N., Balakrishna, K. N., Bhogala, N. & Nangia, A. (2009). Cryst. Growth Des. 9, 1546-1557.]). For fundamental hydrogen-bond inter­actions, see: Desiraju (1995[Desiraju, G. (1995). Angew. Chem. Int. Ed. Engl. 34, 2311-2327.]); Etter (1990[Etter, M. C. (1990). Acc. Chem. Res. 23, 120-126.], 1991[Etter, M. C. (1991). J. Phys. Chem. 9, 4601-4610.]).

[Scheme 1]

Experimental

Crystal data

  • C9H10N2O4·H2O

  • Mr = 228.21

  • Orthorhombic, P n a 21

  • a = 7.4939 (8) Å

  • b = 19.446 (2) Å

  • c = 7.0227 (7) Å

  • V = 1023.39 (19) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 298 K

  • 0.30 × 0.12 × 0.10 mm
Data collection

  • Bruker SMART APEX CCD area-detector diffractometer

  • 10663 measured reflections

  • 1868 independent reflections

  • 1642 reflections with I > 2σ(I)

  • Rint = 0.037
Refinement

  • R[F2 > 2σ(F2)] = 0.028

  • wR(F2) = 0.058

  • S = 0.96

  • 1868 reflections

  • 160 parameters

  • 6 restraints

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

  • Δρmax = 0.11 e Å−3

  • Δρmin = −0.12 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O3—H3⋯O2i 0.87 (1) 1.60 (1) 2.4681 (15) 177 (2)
O5—H5A⋯O4ii 0.85 (1) 2.04 (1) 2.8879 (18) 174 (2)
O5—H5B⋯O1iii 0.86 (1) 1.94 (1) 2.7968 (19) 173 (2)
N2—H2A⋯O5iv 0.91 (1) 2.02 (1) 2.920 (2) 168 (2)
N2—H2B⋯O4iv 0.91 (1) 2.08 (1) 2.987 (2) 173 (2)
Symmetry codes: (i) x-1, y, z; (ii) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z]; (iii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z+{\script{1\over 2}}]; (iv) x, y, z-1.

Data collection: SMART (Bruker, 2007[Bruker (2007). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812006897/fj2513sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812006897/fj2513Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812006897/fj2513Isup3.cml

checkCIF report


Comment top

Crystal engineering is defined in terms of structural geometry and topology (Desiraju, 1995) and hydrogen's rules (Etter, 1990, 1991) are described for predicting hydrogen-bond patterns. Recently, zwitterion derivatives have been of particular interest as building blocks for the synthesis of salts, co-crystals (Kavuru et al. 2010) and polymeric compounds (Hill et al. 2001). For this purpose, hydrogen bonded supramolecular synthons are commonly used to build co-crystals or organic-based self-assembled structures because of their strength and directionality. In this context, aminopyridines and carboxylic acids have been employed for the generation of multicomponent crystals (Bis & Zaworotko, 2005; Sarma et al., 2009). Thus, in this opportunity we would like to describe the molecular and crystal structure of 2-(3-aminopyridinium) succinate acid monohydrate (I).

The asymmetric unit of I contains one 2-(3-aminopyridinium) succinic acid and one water molecule (Figure 1). The 3-aminopyridinium and the di-acid fragment are not coplanar, and are forming dihedral angles of 68.6 (2)° between the aminopyridinium and the carboxylate anion and of 62.8 (2)° between the 3-aminopyridinium fragment and the carboxylic acid group. The carboxylate anion and carboxylic acid fragments are rotated around C2 and C3 respectively, forming an almost perpendicular dihedral angle of 80.6 (1)°. This adopted geometry does not allow the classical dimers as patterns, and form chains along the a axis, via O3—H3—O2. These chains are linked by intermolecular interactions of N2—H2B—O4 thus generating a two-dimensional network along the c axis (Figure 2). The two-dimensional network is interconnected through O5—H5A—O4, O5—H5B—O1 and N2—HA—O5 hydrogen bonds to give an overall three-dimensional hydrogen bonded network (Table 1 and Fig. 2).

Related literature top

For background to the synthesis, see: Kavuru et al. (2010). For structures and applications of zwitterion derivatives, see: Bis & Zaworotko (2005); Hill et al. (2001); Sarma et al. (2009). For fundamental hydrogen-bond interactions, see: Desiraju (1995); Etter (1990, 1991).

Experimental top

A solution of fumaric acid (0.05 g, 430 mmol) in MeOH (5 ml) was mixed at room temperature for 10 min. After this time 3-aminopyridine (0.04 g, 430 mmol) was added and mixed for further 30 minutes. Crystals suitable for single-crystal X ray diffraction studies were grown by slow evaporation at room temperature from a saturated solution of compound (I) in methanol (yield: 60%) m.p. 417 K. IR (KBr): 3414, 3347, 3235, 2581, 2147, 1722, 1652, 1173 y 1090 cm-1.

Refinement top

H atoms on O and N atoms,were located in the Fourier map and refined isotropically (O—H 0.85 Å, N—H, 0.90 Å). All H atoms were included in calculated positions (C—H = 0.93Å for arom, 0.98Å for methine, 0.97Å for methylene), and refined using a riding model,with Uiso(H) = 1.2Ueq of the carrier atom. The absolute configuration was not determined by difraction experiment and the enantiomer refined was fixed arbitrary. 852 Friedel pairs were merged.

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and SHELXL97 (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound (I), with atom labels and displacement ellipsoids drawn at the 40% probability level.
[Figure 2] Fig. 2. Crystal packing of the title compound (I). Only H atoms involved in interactions were drawn.
2-(3-Aminopyridinium-1-yl)-3-carboxypropanoate monohydrate top
Crystal data top
C9H10N2O4·H2OF(000) = 480
Mr = 228.21Dx = 1.481 Mg m−3
Orthorhombic, Pna21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2nCell parameters from 5172 reflections
a = 7.4939 (8) Åθ = 2.9–25.3°
b = 19.446 (2) ŵ = 0.12 mm−1
c = 7.0227 (7) ÅT = 298 K
V = 1023.39 (19) Å3Prism, orange
Z = 40.30 × 0.12 × 0.10 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer		1642 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.037
Graphite monochromatorθmax = 25.3°, θmin = 2.1°
Detector resolution: 0.83 pixels mm-1h = −9→9
ω scansk = −23→23
10663 measured reflectionsl = −8→8
1868 independent reflections
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)] = 0.028Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.058H atoms treated by a mixture of independent and constrained refinement
S = 0.96 w = 1/[σ2(Fo2) + (0.028P)2]
where P = (Fo2 + 2Fc2)/3
1868 reflections(Δ/σ)max < 0.001
160 parametersΔρmax = 0.11 e Å−3
6 restraintsΔρmin = −0.12 e Å−3
Crystal data top
C9H10N2O4·H2OV = 1023.39 (19) Å3
Mr = 228.21Z = 4
Orthorhombic, Pna21Mo Kα radiation
a = 7.4939 (8) ŵ = 0.12 mm−1
b = 19.446 (2) ÅT = 298 K
c = 7.0227 (7) Å0.30 × 0.12 × 0.10 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer		1642 reflections with I > 2σ(I)
10663 measured reflectionsRint = 0.037
1868 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0286 restraints
wR(F2) = 0.058H atoms treated by a mixture of independent and constrained refinement
S = 0.96Δρmax = 0.11 e Å−3
1868 reflectionsΔρmin = −0.12 e Å−3
160 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
O11.04824 (15)0.51597 (6)0.4732 (2)0.0417 (3)
O21.13193 (13)0.41287 (5)0.36700 (19)0.0395 (3)
O30.44407 (15)0.45071 (7)0.4070 (2)0.0565 (4)
H30.3347 (15)0.4376 (9)0.389 (3)0.068*
O40.45279 (16)0.39455 (7)0.67937 (19)0.0528 (4)
O50.59669 (18)0.13525 (7)0.8132 (2)0.0557 (4)
H5A0.6976 (17)0.1248 (11)0.767 (3)0.067*
H5B0.559 (3)0.0989 (7)0.870 (3)0.067*
N10.79643 (15)0.36728 (7)0.3184 (2)0.0291 (3)
N20.6301 (2)0.28176 (8)−0.1026 (2)0.0554 (4)
H2A0.605 (2)0.2377 (6)−0.137 (3)0.066*
H2B0.581 (2)0.3184 (8)−0.163 (3)0.066*
C11.0183 (2)0.45789 (8)0.4126 (2)0.0307 (4)
C20.81973 (19)0.43883 (7)0.3871 (2)0.0299 (4)
H20.76990.46960.29020.036*
C30.7156 (2)0.45043 (9)0.5703 (3)0.0363 (4)
H3A0.77180.42460.67210.044*
H3B0.72170.49880.60360.044*
C40.5235 (2)0.42955 (8)0.5568 (3)0.0341 (4)
C50.7281 (2)0.35719 (8)0.1437 (2)0.0325 (4)
H50.69990.39500.06820.039*
C60.6988 (2)0.29126 (9)0.0739 (3)0.0359 (4)
C70.7427 (2)0.23635 (9)0.1932 (3)0.0411 (5)
H70.72420.19140.15220.049*
C80.8125 (2)0.24828 (8)0.3696 (3)0.0412 (4)
H80.84150.21140.44810.049*
C90.8403 (2)0.31445 (8)0.4320 (3)0.0376 (4)
H90.88910.32250.55170.045*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0332 (7)0.0403 (7)0.0515 (8)−0.0082 (5)−0.0007 (6)−0.0106 (6)
O20.0239 (6)0.0369 (6)0.0577 (8)0.0034 (5)0.0002 (6)−0.0013 (6)
O30.0244 (7)0.0849 (10)0.0600 (9)−0.0104 (6)−0.0076 (8)0.0293 (8)
O40.0381 (8)0.0673 (9)0.0530 (9)−0.0094 (6)−0.0001 (7)0.0195 (8)
O50.0528 (8)0.0420 (7)0.0724 (11)0.0014 (7)0.0116 (8)−0.0036 (8)
N10.0218 (6)0.0325 (7)0.0330 (8)−0.0018 (6)0.0001 (6)−0.0012 (6)
N20.0796 (12)0.0400 (9)0.0466 (11)−0.0056 (9)−0.0157 (10)−0.0030 (9)
C10.0278 (9)0.0351 (9)0.0293 (9)−0.0034 (7)−0.0018 (8)0.0034 (8)
C20.0243 (8)0.0306 (8)0.0349 (10)−0.0011 (6)−0.0011 (8)−0.0015 (8)
C30.0266 (9)0.0443 (10)0.0380 (10)−0.0004 (8)−0.0001 (8)−0.0074 (8)
C40.0261 (9)0.0367 (9)0.0394 (11)0.0021 (8)0.0020 (9)−0.0027 (9)
C50.0304 (9)0.0339 (9)0.0330 (11)−0.0031 (7)0.0021 (8)0.0031 (8)
C60.0346 (9)0.0382 (10)0.0351 (11)−0.0071 (8)−0.0010 (9)−0.0009 (9)
C70.0414 (11)0.0306 (9)0.0512 (13)−0.0046 (8)0.0031 (10)−0.0005 (9)
C80.0428 (10)0.0336 (9)0.0472 (12)−0.0006 (8)−0.0036 (10)0.0065 (9)
C90.0327 (9)0.0421 (10)0.0380 (11)−0.0026 (8)−0.0042 (9)0.0030 (8)
Geometric parameters (Å, º) top
O1—C11.2276 (18)C2—C31.522 (2)
O2—C11.2623 (19)C2—H20.9800
O3—C41.277 (2)C3—C41.499 (2)
O3—H30.868 (9)C3—H3A0.9700
O4—C41.2183 (19)C3—H3B0.9700
O5—H5A0.848 (9)C5—C61.390 (2)
O5—H5B0.861 (9)C5—H50.9300
N1—C91.341 (2)C6—C71.396 (2)
N1—C51.344 (2)C7—C81.365 (3)
N1—C21.4830 (18)C7—H70.9300
N2—C61.355 (2)C8—C91.375 (2)
N2—H2A0.909 (9)C8—H80.9300
N2—H2B0.907 (9)C9—H90.9300
C1—C21.544 (2)
C4—O3—H3117.7 (16)C2—C3—H3B108.9
H5A—O5—H5B106 (2)H3A—C3—H3B107.7
C9—N1—C5121.62 (14)O4—C4—O3124.03 (15)
C9—N1—C2119.75 (14)O4—C4—C3121.62 (16)
C5—N1—C2118.62 (13)O3—C4—C3114.34 (16)
C6—N2—H2A116.6 (14)N1—C5—C6121.11 (15)
C6—N2—H2B118.2 (14)N1—C5—H5119.4
H2A—N2—H2B122.2 (18)C6—C5—H5119.4
O1—C1—O2127.07 (14)N2—C6—C5120.55 (16)
O1—C1—C2115.91 (14)N2—C6—C7122.28 (17)
O2—C1—C2117.02 (14)C5—C6—C7117.17 (17)
N1—C2—C3110.72 (13)C8—C7—C6120.32 (16)
N1—C2—C1112.11 (12)C8—C7—H7119.8
C3—C2—C1111.15 (13)C6—C7—H7119.8
N1—C2—H2107.5C7—C8—C9120.42 (17)
C3—C2—H2107.5C7—C8—H8119.8
C1—C2—H2107.5C9—C8—H8119.8
C4—C3—C2113.52 (14)N1—C9—C8119.35 (16)
C4—C3—H3A108.9N1—C9—H9120.3
C2—C3—H3A108.9C8—C9—H9120.3
C4—C3—H3B108.9
C9—N1—C2—C3−57.28 (17)C2—C3—C4—O3−46.5 (2)
C5—N1—C2—C3121.47 (14)C9—N1—C5—C60.5 (2)
C9—N1—C2—C167.48 (17)C2—N1—C5—C6−178.25 (13)
C5—N1—C2—C1−113.77 (15)N1—C5—C6—N2−179.88 (16)
O1—C1—C2—N1−178.48 (14)N1—C5—C6—C70.3 (2)
O2—C1—C2—N12.4 (2)N2—C6—C7—C8179.63 (17)
O1—C1—C2—C3−53.95 (19)C5—C6—C7—C8−0.5 (3)
O2—C1—C2—C3126.92 (16)C6—C7—C8—C90.1 (3)
N1—C2—C3—C4−51.92 (18)C5—N1—C9—C8−0.9 (2)
C1—C2—C3—C4−177.22 (13)C2—N1—C9—C8177.77 (14)
C2—C3—C4—O4132.57 (18)C7—C8—C9—N10.7 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H3···O2i0.87 (1)1.60 (1)2.4681 (15)177 (2)
O5—H5A···O4ii0.85 (1)2.04 (1)2.8879 (18)174 (2)
O5—H5B···O1iii0.86 (1)1.94 (1)2.7968 (19)173 (2)
N2—H2A···O5iv0.91 (1)2.02 (1)2.920 (2)168 (2)
N2—H2B···O4iv0.91 (1)2.08 (1)2.987 (2)173 (2)
Symmetry codes: (i) x−1, y, z; (ii) x+1/2, −y+1/2, z; (iii) −x+3/2, y−1/2, z+1/2; (iv) x, y, z−1.

Experimental details

Crystal data
Chemical formulaC9H10N2O4·H2O
Mr228.21
Crystal system, space groupOrthorhombic, Pna21
Temperature (K)298
a, b, c (Å)7.4939 (8), 19.446 (2), 7.0227 (7)
V (Å3)1023.39 (19)
Z4
Radiation typeMo Kα
µ (mm−1)0.12
Crystal size (mm)0.30 × 0.12 × 0.10
Data collection
DiffractometerBruker SMART APEX CCD area-detector
diffractometer
Absorption correction–
No. of measured, independent and
observed [I > 2σ(I)] reflections		10663, 1868, 1642
Rint0.037
(sin θ/λ)max (Å−1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.028, 0.058, 0.96
No. of reflections1868
No. of parameters160
No. of restraints6
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.11, −0.12

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and SHELXL97 (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H3···O2i0.868 (9)1.601 (10)2.4681 (15)177 (2)
O5—H5A···O4ii0.848 (9)2.043 (10)2.8879 (18)174 (2)
O5—H5B···O1iii0.861 (9)1.941 (10)2.7968 (19)173 (2)
N2—H2A···O5iv0.909 (9)2.024 (10)2.920 (2)168.3 (18)
N2—H2B···O4iv0.907 (9)2.084 (10)2.987 (2)173 (2)
Symmetry codes: (i) x−1, y, z; (ii) x+1/2, −y+1/2, z; (iii) −x+3/2, y−1/2, z+1/2; (iv) x, y, z−1.
 

Acknowledgements

This work was supported by the Secretaria de Educación Pública (PROMEP, PTC-035) and Universidad Autónoma de Sinaloa (DGIP, PROFAPI-048). Support of this research by CONACyT (grant No. 154732) is gratefully acknowledged.

References

First citationBis, J. A. & Zaworotko, M. J. (2005). Cryst. Growth Des. 5, 1169–1179.  Web of Science CSD CrossRef CAS Google Scholar
 First citationBruker (2007). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationDesiraju, G. (1995). Angew. Chem. Int. Ed. Engl. 34, 2311–2327.  CrossRef CAS Web of Science Google Scholar
 First citationEtter, M. C. (1990). Acc. Chem. Res. 23, 120–126.  CrossRef CAS Web of Science Google Scholar
 First citationEtter, M. C. (1991). J. Phys. Chem. 9, 4601–4610.  CrossRef Web of Science Google Scholar
 First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
 First citationHill, L. W., Rondan, N. & Schmidt, D. (2001). Macromolecules, 34, 372–375.  Web of Science CrossRef CAS Google Scholar
 First citationKavuru, P., Aboarayes, D., Arora, K. K., Clarke, H. D., Kennedy, A., Marshall, L., Ong, T. T., Perman, J., Pujari, T., Wojtas, L. & Zaworotko, M. J. (2010). Cryst. Growth Des. 10, 3568–3584.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSarma, B. N., Balakrishna, K. N., Bhogala, N. & Nangia, A. (2009). Cryst. Growth Des. 9, 1546–1557.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 68| Part 3| March 2012| Page o853
doi:10.1107/S1600536812006897
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