A triclinic polymorph of 4-cyano­pyridinium hydrogen chloranilate

The asymmetric unit of the triclinic polymorph of the title compound (systematic name: 4-cyano­pyridinium 2,5-dichloro-4-hy­droxy-3,6-dioxocyclo­hexa-1,4-dien-1-olate), C(6)H(5)N(2) (+)·C(6)HCl(2)O(4) (−), consists of two crystallographically independent cation–anion units, in each of which the cation and the anion are linked by an N—H⋯O hydrogen bond. In the units, the dihedral angles between the cation and anion rings are 78.43 (11) and 80.71 (11)°. In the crystal, each unit independently forms a chain through N—H⋯O and O—H⋯N hydrogen bonds; one chain runs along the c axis while the other runs along [011]. Weak C—H⋯O, C—H⋯N and C—H⋯Cl inter­actions are observed between the chains.