Redetermination of pyridine-4-carbonitrile–chloranilic acid (1/1) at 180 K

Kazuma Gotoh,Hirokazu Nagoshi,Hiroyuki Ishida

doi:10.1107/s1600536808017182

Kazuma Gotoh, Hirokazu Nagoshi + Show 1 more

Open Access

https://doi.org/10.1107/s1600536808017182

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Abstract

In the crystal structure of the title compound, C6H4N2·C6H2Cl2O4, two chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) molecules are connected by O—H⋯O hydrogen bonds to form a dimeric unit. The pyridine-4-carbonitrile molecules are linked on both sides of the dimer via N⋯H⋯O hydrogen bonds to give a centrosymmetric 2:2 complex of pyridine-4-carbonitrile and chloranilic acid. The H atom in the N⋯H⋯O hydrogen bond is disordered over two positions with approximately equal occupancies. The pyridine ring makes a dihedral angle of 61.54 (14)° with the chloranilic acid plane. The 2:2 units are further linked by intermolecular C—H⋯O and C—H⋯Cl hydrogen bonds. This determination presents a siginficantly higher precision crystal structure than the previously published structure [Tomura & Yamasshita (2008 ▶). X-ray Struct. Anal. Online, 24, x31–x32].

Highlights

In the crystal structure of the title compound, C6H4N2ÁC6H2Cl2O4, two chloranilic acid molecules are connected by O—HÁ Á ÁO hydrogen bonds to form a dimeric unit
The pyridine-4-carbonitrile molecules are linked on both sides of the dimer via NÁ Á ÁHÁ Á ÁO hydrogen bonds to give a centrosymmetric 2:2 complex of pyridine-4-carbonitrile and chloranilic acid
The H atom in the NÁ Á ÁHÁ Á ÁO hydrogen bond is disordered over two positions with approximately equal occupancies

Summary

Structure Reports Online

Key indicators: single-crystal X-ray study; T = 180 K; mean (C–C) = 0.004 A; R factor = 0.058; wR factor = 0.177; data-to-parameter ratio = 18.6. In the crystal structure of the title compound, C6H4N2ÁC6H2Cl2O4, two chloranilic acid (systematic name: 2,5dichloro-3,6-dihydroxy-1,4-benzoquinone) molecules are connected by O—HÁ Á ÁO hydrogen bonds to form a dimeric unit. The pyridine-4-carbonitrile molecules are linked on both sides of the dimer via NÁ Á ÁHÁ Á ÁO hydrogen bonds to give a centrosymmetric 2:2 complex of pyridine-4-carbonitrile and chloranilic acid. The 2:2 units are further linked by intermolecular C—HÁ Á ÁO and C—HÁ Á ÁCl hydrogen bonds. This determination presents a siginficantly higher precision crystal structure than the previously published structure [Tomura & Yamasshita (2008).

Data collection

DÁ Á ÁA

Crystal data

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