4-Cyano­pyridinium dihydrogen phosphate–isonicotinonitrile–phospho­ric acid (1/1/1)

Ying-Chun Wang

doi:10.1107/S1600536812020430

. 2012 May 12;68(Pt 6):o1693–o1694. doi: 10.1107/S1600536812020430

4-Cyanopyridinium dihydrogen phosphate–isonicotinonitrile–phosphoric acid (1/1/1)

Ying-Chun Wang ^a,^*

PMCID: PMC3379289 PMID: 22719487

Abstract

The asymmetric unit of the title compound, C₆H₅N₂ ⁺·H₂PO₄ ⁻·C₆H₄N₂·H₃PO₄, contains one 4-cyanopyridinium cation, one H₂PO₄ ⁻ anion, one independent isonicotinonitrile molecule and one independent H₃PO₄ molecule. The dihedral angle between the mean planes of the separate protonated and unprotonated pyridine rings is 9.93 (8)°. In the crystal, N—H⋯O and O—H⋯N hydrogen bonds and weak C—H⋯O and C—H⋯N intermolecular interactions connect the organic molecules into a two-dimensional network parallel to the ac plane. O—H⋯O hydrogen-bonding interactions involving the H₂PO₄ ⁻ anions and H₃PO₄ molecules provide additional support from the inorganic groups Weak π–π stacking interactions between the pyridine rings of neighbouring organic molecules [centroid–centroid distances = 3.711 (4) and 3.784 (2) Å] further link the layers into a three-dimensional network.

Related literature

For the properties of related compounds, see: Chen et al. (2001 ▶); Huang et al. (1999 ▶); Zhang et al. (2001 ▶). For related structures, see: Wang et al. (2002 ▶); Xue et al. (2002 ▶); Ye et al. (2008 ▶). graphic file with name e-68-o1693-scheme1.jpg

Experimental

Crystal data

C₆H₅N₂ ⁺·H₂O₄P⁻·C₆H₄N₂·H₃O₄P
M _r = 404.21
Triclinic,
a = 8.1040 (5) Å
b = 8.8872 (9) Å
c = 12.1606 (8) Å
α = 81.491 (1)°
β = 82.009 (1)°
γ = 79.133 (1)°
V = 845.07 (11) Å³
Z = 2
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 173 K
0.10 × 0.05 × 0.05 mm

Data collection

Rigaku Mercury2 diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.910, T _max = 1.000
8963 measured reflections
3798 independent reflections
3306 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.096
S = 1.14
3798 reflections
235 parameters
6 restraints
H-atom parameters constrained
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812020430/jj2136sup1.cif

e-68-o1693-sup1.cif^{(24.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812020430/jj2136Isup2.hkl

e-68-o1693-Isup2.hkl^{(186.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812020430/jj2136Isup3.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
O2—H2⋯O5ⁱ	0.82	1.75	2.5576 (14)	169
O4—H4⋯O3ⁱⁱ	0.82	1.74	2.5611 (14)	176
O6—H6⋯N1ⁱⁱⁱ	0.82	1.86	2.6749 (17)	178
O7—H7⋯O1^iv	0.82	1.70	2.5150 (15)	173
O8—H8⋯O3ⁱⁱ	0.82	1.76	2.5795 (15)	177
N3—H3⋯O1	0.90	1.77	2.6466 (16)	162
C1—H1A⋯O2^v	0.95	2.44	3.2549 (19)	144
C8—H8A⋯N2^vi	0.95	2.51	3.273 (2)	138
C10—H10A⋯O7^vii	0.95	2.31	3.1631 (19)	149
C11—H11A⋯O1^v	0.95	2.52	3.3321 (19)	144

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

Acknowledgments

This work was supported by a start-up grant from Southeast University, China.

supplementary crystallographic information

Comment

Simple organic salts containing strong intrermolecular H-bonds have attracted attention as materials which display ferroelectric-paraelectric phase transitions (Chen et al., 2001; Huang, et al. 1999; Zhang, et al. 2001). In an effort to obtain phase transition crystals of organic salts, various organic molecules have been studied with a series of new crystal materials (Wang et al., 2002; Xue, et al. 2002; Ye et al., 2008). Herewith, we present the synthesis and crystal structure of the title compound, C₆H₅N₂⁺.H₂PO₄^-.C₆H₄N₂.H₃PO₄,(I).

The asymmetric unit of (I) is comprised of one 4-cyanopyridinium cation, one H₂PO₄^- anion, one independent isonicotinonitrile molecule and one independent H₃PO₄ molecule (Fig. 1). The two separate pyridine rings in the asymmetric unit are almost planar with the largest deviation from the least-squares plane being 0.001 (1) Å and 0.003 (1) Å, respectively. The dihedral angle between the mean planes of the two separate pyridine rings is 9.93 (8)°. Bond lengths and angles in each of these units are in normal ranges.

In the crystal N—H···O and O—H···N hydrogen bonds and weak C—H···O and C—H···N intermolecular interactions bring the organic molecules into a 2D network (Fig. 2). Also, O—H···O hydrogen bonding interactions involving the H₂PO₄^- anions and H₃PO₄ molecules provide additional support for the 2D network from the inorganic groups (Table 1, Fig. 3). In addition, weak π–π stacking interactions between the pyridine rings of neighbouring organic molecules further link the layers into a 3D network (Cg1···Cg2 = 3.711 (4) Å and Cg1···Cg2 = 3.784 (2) Å, where Cg1 and Cg2 are the centroids of the pyridine rings, N1/C1/C2/C3/C4/C5 and N3/C7/C8/C9/C10/C11, respectively).

Experimental

Isonicotinonitrile (10 mmol and stirred at 60°C for 2 h. The precipitate was then filtrated. Colourless crystals suitable for X-ray diffraction were obtained by slow evaporation of the solution.