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.