The charge distribution in complexes Mo–Mo or Cr–Cr ‘quadruple’ bonds, studied by gas-phase X-ray photoelectron spectroscopy

Abstract

The gas-phse core-electron ionization emergies of M₂L₄(M = Cr, L = O₂CMe or mhp; M = Mo, L = O₂CH, O₂CMe, or mhp)(Hmhp = 2-hydroxy-6-methyl-pyridine) are reported and lead to the important conclusion that the charge distribution is the same within [Cr₂(O₂CMe)₄]and[Mo₂(O₂CMe)₄] and within [Cr₂(mhp)₄]and[Mo₂(mhp)₄] despite the large variations in the metal-metal bond lengths for these pairs of molecules.