Reactivity of di(azido)bis(phosphine) complexes of Ni(ii), Pd(ii) and Pt(ii) toward organic isothiocyanates: synthesis, structures, and properties of bis(tetrazole-thiolato) and bis(isothiocyanato) complexes

Abstract

Di(azido)bis(phosphine) complexes of Group 10 metals {M(N3)2(PR3)2} underwent substitution with trimethylsilyl isothiocyanate (Me3Si–NCS) to give the corresponding bis(isothiocyanato) complexes, M(NCS)2L2 (M = Pd, L = PMe3 (1), PEt3 (2), PMe2Ph (3); M = Ni, L = PMe3 (4); M = Pt, L = PEt3 (5)), in which the isothiocyanato ligand is N-bound to the metal. By contrast, the bis(azido) complexes of Pd(II) and Pt(II) underwent 1,3-cycloaddition with organic isothiocyanates (R–NCS) to give tetrazole-containing thiolato complexes, M{S[CN4(R)]}2L2 (M = Pd, L = PMe3, R = allyl (6), benzyl (7), ethyl (8), phenyl (9), 2,6-dimethylphenyl (10); L = PMe2Ph, R = phenyl (11); L = PEt3, R = 2,6-dimethylphenyl (12); M = Pt, L = PMe3, R = Ph (13), Et (14); L = PEt3, R = Ph (15)). The chelating phosphine analogues, M{S[CN4(R)]}2L2 (L–L = depe (1,2-bis(diethylphosphino)ethane): R = Ph, M = Pd (16), Pt (17); R = 2,6-dimethylphenyl, M = Pt (18)) could also be obtained. Molecular structures of 6, 9, 14 and 18 clearly show the S-coordination of the thiolato ligands in these complexes. Treatments of tetrazole-thiolate complexes with benzoyl halide derivatives afforded various organic sulfides