Crystal structure, vibrational spectra and normal coordinate analysis of trans-(Et4N)[OsF4Cl2]

By careful oxidation of trans-tetrafluorodichloroosmate(IV) with PbO2/trifl uoroacetic acid in dichloromethane the corresponding osmium(V) complex anio n trans-[OsF4Cl2](-) is formed. The X-ray structure determination on a sing le crystal has been performed of trans-(Et4N)[OsF4Cl2] (triclinic, space gr oup P (1) over bar, a = 7.190(5), b = 7.205(5), c = 7.732(5) Angstrom, alph a = 71.28(1), beta = 71.32(1), gamma = 70.76(1)degrees, Z = 1). Based on th e molecular parameters of the X-ray determination the IR and Raman spectra of the complex have been assigned by normal coordinate analysis. The valenc e force constants are: f(d)(OsCl) = 2.13 and f(d),(OsF) = 3.81 mdyn/Angstro m.