Photoelectron studies of metal carbonyls. Part 5.—Substituted group VIIA carbonyls

Abstract

The He I and He II spectra of the compounds M(CO)5X and M2CO10(M = Mn, Re; X = Cl, Br, I), valence region X-ray photoelectron spectra of M2(CO)10, and the He I spectra of some related compounds are reported and discussed. From observations of intensity changes it is deduced that in M(CO)5I and Re(CO)5 Br the orbital ionisation sequence for the low ionisation potential region is e(X) < b2(M) < e(M) < a1(M—X σ bonding), but that in M(CO)5Cl and Mn(CO)5Br the sequence of e orbital ionization potentials is reversed. These assignments remove several inconsistencies which existed between earlier assignments and observations upon other compounds. Probable orbital sequences for other M(CO)5L compounds are discussed.