That OsCl(CO)(NO)(PPh3)2 (Ph=phenyl=C6H5) reacts with HCl to form OsCl2(CO)(HNO)(PPh3)2 is confirmed by a structural and spectroscopic study of the product. The octahedrally coordinated Os(II) ion possesses trans phosphine ligands, cis chloro ligands, a carbonyl group, and a HNO molecule coordinated through the N atom. Important metrical details for this coordination are Os-N=1.915 (6) Å, N-O=1.193 (7) Å, N-H=0.94 (11) Å, Os-N-O=136.9 (6)°, Os-N-H=123 (7)°, and O-N-H=99 (7)°. These results have been derived from a three-dimensional X-ray study of OsCl2(CO)(HNO)(PPh3)2·1/2CH2Cl2, based on 185 variables and 5563 significant observations. The material crystallizes with four molecules in space group C2h5-P21/n of the monoclinic system in a cell of dimensions a=10.849 (2) Å, b=33.272 (7) Å, c=10.036 (3) Å, and β=104.56 (1)°. The N-O stretching frequency has been identified at 1410 cm-1 from the spectra of the unlabeled and 15N-labeled species. Coordination of HNO in solution has been established from the 1H NMR spectra of OsCl2(CO)(H14NO)(PPh3)2 and the corresponding 15N derivative, which show the chemical shift of the unique proton at δ=21.2. Consistent with the solid-state study, the 1H-15N coupling constant of 75 Hz implies that the ligand is HNO rather than HON. Reaction of a noncoordinating acid, HBF4, with OsCl(CO)(NO)(PPh3)2 yields a variety of products, including [OsCl2(CO)(NO)(PPh3)2] [BF4] whose identity was established by crystallographic methods.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry