Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von (Ph3PNPPh3)[OsF5Cl]·CH2Cl2 und cis-(Ph3PNPPh3)[OsF4Cl2]·CH2Cl2 / Crystal Structures, Vibrational Spectra and Normal Coordinate Analysis of (Ph3PNPPh3) [OsF5Cl]·CH2Cl2 and cis-(Ph3PNPPh3 )[OsF4Cl2]·CH2Cl2

Abstract

By careful oxidation of the pure fluorochloroosmates(IV) with BrF3 in dichloromethane the mixed pentavalent complex anions [OsF5Cl]- and cis -[OsF4Cl2]- are formed. X-ray structure determinations on single crystals have been performed of (Ph3PNPPh3)[OsF5Cl]·CH2Cl2 (1) (triclinic, space group P1̄, a = 12.153(5), b = 12.387(5), c = 14.229(5) Å , α = 70.07(1), β = 65.46(1), γ = 72.87(1)°, Z = 2) and cis-(Ph3PNPPh3)[OsF4Cl2]·CH2Cl2 (2) (triclinic, space group P1̄, a = 11.987(2) b = 13.083(2), c = 14.456(2) Å, α = 66.30(1), β = 65.47(1), γ = 71.22(1)°, Z = 2). Based on the molecular parameters of the X-ray determinations the IR and Raman spectra for the anions of 1 and 2 have been assigned by normal coordinate analysis. Due to the mutual trans influences the valence force constants of asymmetrically coordinated octahedral axes F•-Os-Cl′ differ from those of the symmetric F-Os-F axes. The data are for 1: fd(OsF•) = 3.95, fd(OsF) = 4.07, fd(OsCl′) = 2.51 and for 2: fd(OsF•) = 3.45, fd(OsF) = 3.97, fd(OsCl′) = 2.42 mdyn/Å