Bis[4-(salicylideneamino)phenyl]methane

The crystal structure of the title Schiff base {systematic name: 2,2'-[methylenedi-p-phenylenebis(nitrilomethylidyne)]diphenol}, C27H22N2O2, consists of intramolecularly hydrogen-bonded molecules interlinked by C-H center dot center dot center dot O hydrogen bonds [C center dot center dot center dot O = 3.426 (2) angstrom and C-H center dot center dot center dot O = 152.7 (17)degrees]. The molecule is in the enol form and is located on a twofold axis. The central methane C atom of the diphenylmethane motif is displaced from the aromatic ring planes. This effect is compared with previous results, which display an inverse correlation between the out-of-plane displacement and the C-C-C angle around the central methane C atom. In the title compound, the displacement is 0.124 (2) angstrom and the C-C-C angle is 110.18 (19)degrees.