Osmium nitrosyl complexes with osmium-tin bonds crystal structure of Os[Sn( p-tolyl)3](NO)(CO)2(PPh3)

Article abstract of DOI:10.1016/S0022-328X(97)00101-0

Oxidative addition of the tin-hydride bond of (p-tolyl)₃SnH to the formal osmium(0) nitrosyl complexes, OsCl(NO)(PPh₃)₃ and OsH(NO)(PPh₃)₂ , affords the osmium(II) stannyl complexes, Os[Sn(p-tolyl)₃]HCl(NO)(PPh₃)₂ (1), and Os[Sn(p-tolyl)₃]H₂(NO)PPh₃)₂ (2) respectively. OsH(NO)(PPh₃)₂ was generated in situ by thermal elimination of H₂ from OsH₃(NO)(PPh₃)₂ (5). It was established from ¹H and ³¹P NMR evidence that 1 has two cis phosphine ligands, one of which is trans to the hydride ligand and the other trans to the stannyl ligand. The high trans influence of the hydride ligands confers lability on one phosphine ligand, which can be readily replaced by reaction with sodium dimethyldithiocarbamate forming OsH[Sn(p-tolyl)₃](S₂CNMe₂)(NO)(PPh₃) (3), and reaction with carbon monoxide gives eventually, after displacement of one triphenylphosphine and loss of HCl, Os[Sn(p-tolyl)₃](NO)(CO)₂(PPh₃) (4), a formal osmium(0) stannyl complex. The crystal structure of this five-coordinate osmium-tin complex, 4, has been determined.