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

Article abstract of DOI:10.1039/b305341p

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.