Quinoline-2-carbonitrile–fumaric acid (1/0.5)

The asymmetric unit of the title compound, C(10)H(6)N(2)·0.5C(4)H(4)O(4), consists of one quinoline-2-carbonitrile mol­ecule and a half-mol­ecule of fumaric acid, which lies on an inversion center. The quinoline-2-carbonitrile mol­ecule is almost planar, with an r.m.s. deviation of 0.008 (1) Å. The acid and base are linked together via pairs of inter­molecular C—H⋯O and O—H⋯N hydrogen bonds, forming R (2) (2)(8) ring motifs. In the crystal, the carbonitrile mol­ecules are further linked by inter­molecular C—H⋯N hydrogen bonds, generating R (2) (2)(10) ring motifs, resulting in zigzag chains running along the c axis.