(Z)-(1,2-Dichlorovinyl)diphenylphosphine oxide

The title compound, C(14)H(11)Cl(2)OP, was synthesized by the reaction of diphenyl-phosphine oxide with 1,2-dichloro-ethyne under CuI catalysis. The reaction provided the Z isomer regioselectively. Two O-P-C bond angles [114.3 (1) and 112.5 (1)°] are significantly larger than the C-P-C [107.7 (1), 105.6 (1) and 106.6 (1)°] and another O-P-C angle [109.5 (1)°], indicating significant distortion of the tetra-hedral configuration of the P atom. In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O hydrogen bonds into centrosymmetric dimers, which are connected by further C-H⋯O inter-actions into chains along [101].