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

Arylselenium(II) derivatives of dithiophosphorus ligands of type 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 = OPri (6)] were prepared by redistribution reactions between Ar2Se2 and [R2P(S)S]2. The derivative [2-{O(CH2CH2)2NCH2}C6H4]SeSP(S)Ph2 (5) was obtained by the salt metathesis reaction between [2-{O(CH2CH2)2NCH2}C6H4]SeCl and NH4S2PPh2. The compounds were investigated by multinuclear (1H, 13C, 31P, 77Se) NMR and infrared spectroscopy. The crystal and molecular structures of 1, 3, 4 and 6 were determined by single-crystal X-ray diffraction. In compounds 3, 4 and 6 the N(1) atom is intramolecularly coordinated to the selenium center, resulting in a T-shaped geometry (hypervalent 10-Se-3 species). The dithiophosphorus ligands act as anisobidentate in 1 and monodentate in 3, 4 and 6. Supramolecular architectures based on intermolecular S⋯H and N⋯H contacts between molecular units are formed in the hypervalent derivatives 3 and 4, while in the compounds 1 and 6 the molecules are associated into polymeric chains through either Se⋯S or O⋯H contacts, with no further inter-chain interactions.