2,2'-Dihydroxybiphenyl-3,3'-di-carb-aldehyde dioxime.

The mol-ecule of the title compound, C(14)H(12)N(2)O(4), lies across a crystallographic inversion centre situated at the mid-point of the C-C intra-annular bond. The mol-ecule is not planar, the dihedral angle between the aromatic rings being 50.1 (1)°. The oxime group is in an E position with respect to the -OH group and forms an intra-molecular O-H⋯N hydrogen bond. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link mol-ecules into chains propagating along [001]. The crystal structure is further stabilized by inter-molecular stacking inter-actions between the rings [centroid-to-centroid distance = 3.93 (1) Å], resulting in layers parallel to the bc plane.