Three-centre hydrogen bonds in triphenyl-phosphine oxide-hydro-quinone (1/1).

The title cocrystal, C(18)H(15)OP·C(6)H(6)O(2), belongs to a series of mol-ecular systems based on triphenyl-phosphine P-oxide. The O atom of the oxide group acts as an acceptor for hydrogen bonds from OH groups of two hydro-quinone mol-ecules which lie on inversion centres [O⋯O = 2.7451†(17) and 2.681†(2)†à ]. The crystal structure is stabilized by weak C-H⋯O hydrogen bonds, forming a C(2) (1)(8) chain which runs parallel to the [100] direction.