Infrarot-Spektren und Struktur einiger Trifluormethyl-Element-Derivate des Mangancarbonyls

Abstract

Infra-red data in the CO stretching region are recorded for a series of complexes having the formulae Mn2(CO)8E(CF3)2X [E = P, X = Cl, Br, I, SCF3, SeCF3, P(CF3)2, SCH3, P(CH3)2; E = As, X = I, SCF3, SeCF3] and Mn2(CO)8(ECF3)2 (E = S, Se). The spectra support the structural formula deduced from chemical and n.m.r. investigations. Considerations of frequency changes and intensities of the bands enable the four series observed to be assigned in pairs to the vibrations of CO groups that are coplanar with the bridge bonds, and those which are oriented perpendicular to this plane. Informations about the ligand properties of the bridging groups are obtained from the spectra.