Osmium complexes containing either chelating or non-chelating 8-quinolyl ligands

Article abstract of DOI:10.1016/S0022-328X(97)00409-9

The reaction of Qn₂Hg (Qn = 8-quinolyl) with OsHCl(CO)(PPh₃)₃ gives Os(η²-Qn)Cl(CO)(PPh₃)₂ (1), in which the 8-quinolyl ligand binds through both N and C-8 forming a 4-membered chelate ring. Reaction of 1 with AgPF₆ to remove chloride, followed by addition of either NaI or NaS₂CNMe₂, gives the neutral compounds Os(η²-Qn)I(CO)(PPh₃)₂ (2) or Os(η¹-Qn)(η²-S₂CNMe₂)(CO)(PPh₃)₂ (3), respectively, while reaction with AgPF₆ followed by CO gives [Os(η²-Qn)(CO)₂(PPh₃)₂]⁺PF^-₆ (4). Single crystal X-ray structures of 2 and 3 have been determined. In 2, the 8-quinolyl ligand is chelated through C-8 and N, but in 3 it is coordinated only through C-8.