6-Nitro­benzimidazolium dihydrogen phosphate 6-nitro­benzimidazole solvate dihydrate

Zhi-Dong Shao; Xiao Jiang; Shao-Min Lan; Wen-Jing Di; Yun-Xiao Liang

doi:10.1107/S1600536810023603

. 2010 Jun 23;66(Pt 7):o1757–o1758. doi: 10.1107/S1600536810023603

6-Nitrobenzimidazolium dihydrogen phosphate 6-nitrobenzimidazole solvate dihydrate

Zhi-Dong Shao ^a, Xiao Jiang ^a, Shao-Min Lan ^a, Wen-Jing Di ^a, Yun-Xiao Liang ^a,^*

PMCID: PMC3006800 PMID: 21587973

Abstract

In the crystal structure of the title compound, C₇H₆N₃O₂ ⁺·H₂PO₄ ⁻·C₇H₅N₃O₂·2H₂O, the components are connected through O—H⋯O, N—H⋯O and O—H⋯N hydrogen-bonding interactions, forming a sheet-like structure parallel to (101). Adjacent sheets are further linked together by strong O—H⋯O hydrogen-bonds involving the dihydrogenphosphate groups. π–π stacking interactions between neighbouring aromatic constituents [centroid–centroid distance 3.653 (3) Å] help to consolidate the crystal packing.

Related literature

For the preparation of inorganic metal phosphates, see: Benard et al. (1996 ▶); Jensen et al. (2000 ▶). For template synthesis of phosphates, see: Sameski et al. (1993 ▶); Lii et al. (1998 ▶). For phosphates with organic cations, see: Dakhlaoui et al. (2007 ▶).

Experimental

Crystal data

C₇H₆N₃O₂ ⁺·H₂PO₄ ⁻·C₇H₅N₃O₂·2H₂O
M _r = 460.31
Triclinic,
a = 9.4683 (19) Å
b = 9.990 (2) Å
c = 11.407 (2) Å
α = 90.73 (3)°
β = 107.10 (3)°
γ = 111.66 (3)°
V = 949.4 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 293 K
0.37 × 0.32 × 0.12 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.924, T _max = 0.975
9332 measured reflections
4286 independent reflections
2827 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.141
S = 1.14
4286 reflections
280 parameters
H-atom parameters constrained
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPII (Johnson, 1976 ▶) and DIAMOND (Brandenburg, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810023603/wm2359sup1.cif

e-66-o1757-sup1.cif^{(19.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810023603/wm2359Isup2.hkl

e-66-o1757-Isup2.hkl^{(210KB, hkl)}

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

Table 1. Selected bond lengths (Å).

P1—O8	1.500 (2)
P1—O7	1.504 (2)
P1—O5	1.5591 (19)
P1—O6	1.562 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O7ⁱ	0.86	1.74	2.600 (2)	179
N2—H2A⋯O9	0.86	1.92	2.752 (2)	164
O6—H6A⋯N4ⁱⁱ	1.03	1.66	2.665 (2)	165
O5—H5A⋯O8ⁱⁱⁱ	0.91	1.62	2.531 (2)	174
N5—H5B⋯O7	0.86	1.91	2.773 (2)	176
O9—H9A⋯O4^iv	0.91	2.43	3.161 (2)	137
O9—H9B⋯O10^v	0.85	1.92	2.754 (2)	165
O10—H10A⋯O8	0.91	1.85	2.740 (2)	169
O10—H10B⋯O9ⁱⁱⁱ	0.84	2.16	2.917 (2)	149

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

Acknowledgments

This work was supported by the Ningbo Natural Science Foundation (grant Nos. 2007 A610022 and 2009 A610052) and the K. C. Wong Magna Fund in Ningbo University.

supplementary crystallographic information

Comment

Phosphates are of great interest because of their rich crystal chemistry and practical applications. Up to now, numerous inorganic metal phosphates have been reported (e.g. Benard et al., 1996; Jensen et al., 2000). Furthermore, various of these phosphates were synthesized by structure-orienting templates molecules, most ferquently amines (Sameski et al., 1993; Lii et al., 1998). Compared with these inorganic phosphates, the synthesis of non-metal phosphates was less well explored in the past decades (Dakhlaoui et al., 2007). Herein, we describe the synthesis and crystal structure of the title compound (I), a new non-metal phosphate with formula (C₇H₆N₃O₂)[H₂PO₄]^.(C₇H₅N₃O₂)^.2(H₂O)

As shown in Fig.1, the structure of (I) consists of one (C₇H₆N₃O₂)⁺ cation, one [H₂PO₄]^- anion, one (C₇H₅N₃O₂) solvent molecule and two H₂O molecules, viz. one imidazole molecule is protonated, one imidazole molecule acts as an unprotonated solvent and a dihydrogenphosphate group is present. The O—P—O angles are in the range 105.62 (11)—115.73 (13) °. The P—O bond lengths to the terminal O atoms are 1.500 (2) and 1.504 (2) Å while the P—OH bond lengths are considerably longer with 1.5591 (19) and 1.562 (2) Å.

As is well known, hydrogen bonding interactions play an important role in the formation and stability of low-dimensional structures. In the present structure, the [(C₇H₆N₃O₂)]⁺ cations, [H₂PO₄]^- anions, (C₇H₅N₃O₂) and H₂O molecules are linked together through hydrogen bonds: N1—H1A···O7, N5—H5B···O7; N2—H2A···O9, O6—H6A···N4, O9—H4A···O4, O9—H9B···O10, O10—H10B···O3 (Fig. 2), forming a two-dimensional sheetlike structure parallel to (101). Adjacent sheets are further linked together by strong H-bonding interactions [O5—H5A···O8, O10—H10A···O8, O10—H10B···O9]. π—π stacking interactions between neighboring 6-nitrobenzimidazole molecules with an interplanar distance of 3.653 (3) Å help to consolidate a three-dimensional supramolecular network structure (Fig. 3).

Experimental

The title compound was obtained by the reaction of phosphoric acid, 6-nitrobenzimidazole and methanol/distilled water under room temperature. Typically, a mixture of phosphoric acid (0.2 ml), analytically pure 6-nitrobenzimidazole (0.164 g) and methanol/distilled water (10 ml/10 ml) was stirred at room temperature before it was filtered. The final filtrate was allowed to evaporate slowly at room temperature for 7 days to obtain yellow crystals.