Carbon-13 NMR studies of oxo-centered trinuclear chromium(III) complexes of the general formula [Cr3O(O2CR)6(L)3]+ (R = Me, Ph; L = H2O, py)

Abstract

¹³C NMR resonances of a series of oxo-centered trinuclear chromium complexes have been observed and assigned. A π-delocalization mechanism dominates where ligands contain aromatic substituents or bridging carboxylate functionalities, consistent with the presence of a metal center where to first approximation unpaired electrons reside solely in t_2g. orbitals. A contrast is made between the delocalization mechanism in these complexes and those of their isostructural Mn and Fe analogues.