Bis(4-pyrid-yl) disulfide-2,2'-[(p-phenyl-enebis(-oxy)]diacetic acid (1/1)

The asymmetric unit of the title 1:1 co-crystal, C(10)H(8)N(2)S(2)·C(10)H(10)O(6), comprises two half-mol-ecules, the bis-(4-pyrid-yl) disulfide having twofold rotational symmetry and the 2,2'-[(p-phenyl-enebis(-oxy)]diacetic acid having crystallographic inversion symmetry. In the disulfide mol-ecule, the dihedral angle between the two pyridine rings is 86.8 (1)°, while the carboxyl groups of the substituted quinone lie essentially in the plane of the benzene ring [dihedral angle = 5.3 (1)°]. In the crystal, the components are linked via inter-molecular O-H⋯N hydrogen bonds into zigzag chains which extend along c and are inter-linked through C-H⋯π associations.