Chemistry of polynuclear compounds. Part V. The vibrational spectra of some phosphine derivatives of manganese carbonyl

Abstract

The C–O stretching fundamentals of a series of compounds of the type 9,10-(R₃P)₂Mn₂(CO)₈ have been assigned with the help of binary combination spectra. Complete sets of force constants of the Cotton–Kraihanzel type have been obtained and, in order to check the assignments, the frequencies of some naturally occurring ¹³CO-containing molecules have been calculated and found to agree with weak bands observed in the spectra. The values of the force constants are discussed in relation to the structures of the molecules. The data imply that there is no conjugated π-interaction between the two metal fragments.