Bis(guanidinium) 4,5-dichloro­phthalate monohydrate

Graham Smith; Urs D Wermuth

doi:10.1107/S1600536811021192

. 2011 Jun 11;67(Pt 7):o1645. doi: 10.1107/S1600536811021192

Bis(guanidinium) 4,5-dichlorophthalate monohydrate

Graham Smith ^a,^*, Urs D Wermuth ^a

PMCID: PMC3152114 PMID: 21837049

Abstract

In the structure of the title hydrated salt, 2CH₆N₃ ⁺·C₈H₂Cl₂O₄ ²⁻·H₂O, the planes of the carboxylate groups of the dianion are rotated out of the plane of the benzene ring [dihedral angles = 48.42 (10) and 55.64 (9)°]. A duplex-sheet structure is formed through guanidinium–carboxylate N—H⋯O, guanidinium–water N—H⋯O and water–carboxylate O—H⋯O hydrogen-bonding associations.

Related literature

For the structures of 1:1 salts of 4,5-dichlorophthalate, see: Mallinson et al. (2003 ▶); Bozkurt et al. (2006 ▶); Smith et al. (2008 ▶, 2009 ▶); Smith & Wermuth (2010a ▶,d ▶). For 1:2 salts, see: Büyükgüngör & Odabaşoğlu (2007 ▶); Smith & Wermuth (2010a ▶,c ▶). For guanidinium salts of aromatic dicarboxylic acids, see: Krumbe & Haussuhl (1986 ▶); Smith & Wermuth (2010b ▶).

Experimental

Crystal data

2CH₆N₃ ⁺·C₈H₂Cl₂O₄ ²⁻·H₂O
M _r = 371.19
Monoclinic,
a = 15.9797 (5) Å
b = 6.9432 (2) Å
c = 15.2266 (5) Å
β = 94.650 (3)°
V = 1683.84 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.42 mm⁻¹
T = 200 K
0.28 × 0.25 × 0.20 mm

Data collection

Oxford Diffraction Gemini-S CCD area-detector diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.933, T _max = 0.990
11236 measured reflections
3319 independent reflections
2627 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.105
S = 1.16
3319 reflections
264 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.83 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811021192/ng5176sup1.cif

e-67-o1645-sup1.cif^{(18.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811021192/ng5176Isup2.hkl

e-67-o1645-Isup2.hkl^{(159.5KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811021192/ng5176Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1A—H11A⋯O1Wⁱ	0.83 (2)	2.14 (2)	2.966 (2)	171 (2)
N1A—H12A⋯O12	0.89 (2)	2.07 (2)	2.914 (2)	156.8 (19)
N1B—H11B⋯O22ⁱⁱ	0.88 (2)	2.07 (2)	2.936 (2)	166.3 (19)
N1B—H12B⋯O12ⁱⁱⁱ	0.85 (2)	2.09 (2)	2.904 (2)	162 (2)
N2A—H21A⋯O11	0.89 (3)	2.59 (3)	3.447 (2)	160 (2)
N2A—H21A⋯O12	0.89 (3)	2.35 (3)	3.125 (2)	145 (2)
N2A—H22A⋯O1W^iv	0.81 (3)	2.20 (3)	3.010 (2)	175 (2)
N2B—H21B⋯O22ⁱⁱⁱ	0.86 (3)	2.07 (3)	2.894 (2)	161 (3)
N2B—H22B⋯O11	0.91 (3)	2.09 (3)	2.880 (2)	144 (2)
N3A—H31A⋯O11^v	0.85 (3)	2.06 (3)	2.874 (2)	159 (2)
N3A—H32A⋯O22ⁱ	0.84 (2)	2.19 (2)	2.923 (2)	147 (2)
N3B—H31B⋯O21	0.89 (2)	1.92 (2)	2.799 (2)	169 (2)
N3B—H32B⋯O11^vi	0.86 (2)	2.20 (2)	2.966 (2)	149.2 (19)
O1W—H11W⋯O21	0.83 (3)	1.97 (3)	2.789 (2)	169 (3)
O1W—H12W⋯O12^vi	0.88 (3)	1.90 (3)	2.7716 (19)	174 (3)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

Acknowledgments

The authors acknowledge financial support from the Australian Reseach Council, and from the Faculty of Science and Technology and the University Library, Queensland University of Technology.

supplementary crystallographic information

Comment

4,5-Dichlorophthalic acid (DCPA) forms 1:1 salts with a number of Lewis bases, having most commonly low-dimensional hydrogen-bonded structures featuring the `planar' hydrogen phthalate anion (Mallinson et al., 2003; Bozkurt et al., 2006; Smith et al., 2008, 2009; Smith & Wermuth, 2010a,d). The `nonplanar' dianionic DCPA species is much less common among the known structures, examples being the 1:2 salts with 4-ethylaniline (Büyükgüngör & Odabaşoğlu, 2007), ethylenediamine (Smith & Wermuth, 2010c), n-butylamine and piperidine (Smith & Wermuth, 2010a). With the strong base guanidine, the formation of 1:2 salts with dicarboxylic acids is more common, e.g. with phthalic acid (Krumbe & Haussuhl, 1986) and terephthalic acids (Smith & Wermuth, 2010b) and our 1:1 stoichiometric reaction of DCPA with guanidine carbonate not unexpectedly gave the bis(guanidinium) salt hydrate, the title compound, 2(CH₆N₃⁺) C₈H₂Cl₂O₄^2-. H₂O (I) (Fig. 1), and the structure is reported here.

In the structure of (I), the two guanidinium cations (A and B) and the water molecule of solvation provide hydrogen-bonding links between the `non-planar' DCPA dianions (Table 1). The planes of the carboxyl groups of the dianion are rotated out of the plane of the benzene ring [torsion angles C1—C2—C21–O22, -131.93 (17)°; C2—C1—C11–O11, -129.41 (16)°]. Duplex-sheet structures are formed, extending down the (011) planes in the unit cell (Fig. 2). Within these sheets there are guanidinium N—H···O_carboxyl, N—H···O_water and water O—H···O_carboxyl associations.

Experimental

Compound (I) was synthesized by heating together for 10 min under reflux, 1 mmol quantities of 4,5-dichlorophthalic acid and guanidine carbonate in 50 ml of 50% ethanol–water. Total evaporation of solvent gave a white non-crystalline powder which on subsequent slow room-temperature evaporation of an aqueous solution gave colourless crystalline plates of (I) from which a specimen was cleaved for the X-ray analysis.