Electronic structure and assignment of the ultraviolet photoelectron spectra of 6-methyl-2-oxo-pyridine complexes of dichromium(II) and dimolybdenum(II)

Abstract

The assignment of the photoelectron (p.e.) spectrum of 6-methyl-2-hydroxypyridine H{MHP} has been improved by carrying out an ab initio molecular orbital calculation for the enol form of 2-hydroxypyridine. This, together with p.e. spectral data for Mo₂(MHP)₂(O₂CMe)₂ and He(I) and He(II) spectral data for Cr₂(MHP)₄ and Mo₂(MHP)₄, has proved valuable in the assignment of the p.e. spectra of these latter complexes. Clear evidence is obtained for a stronger metal–metal interaction in M₂(MHP)₄(M = Cr or Mo) complexes, as compared with the corresponding M₂(O₂CMe)₄ complexes.