Organoselenium(II) complexes containing organophosphorus ligands. Crystal and molecular structure of PhSeSP(S)Ph2, [2-{MeN(CH2CH2)2NCH2}C6H4]SeSP(S)R′2 (R′ = Ph, OPri) and [2-{O(CH2CH2)2NCH2}C6H4]SeSP(S)(OPri)2

ArSeSP(S)R2 [Ar = Ph, R = Ph (1), OPri (2); 2-[MeN(CH2CH2)2NCH2]C6H4, R = Ph (3), OPri (4); 2-[O(CH2CH2)2NCH2]C6H4, R = Ph(5), OPri (6)] were investigated by solution NMR and the structures of 1, 3, 4 and 6 were established by single-crystal X-ray diffraction. In 3, 4 and 6 a C,N-ligand prevents any intra- or intermolecular Se⋯S interactions and a T-shaped (C,N)SeS core is achieved.