Photochemistry of ReR(CO)3(Pri-dab)(R = Me, Et, Bn; dab = 1,4-diazabuta-1,3-diene): homolysis of the Re–R bond, its dependence on R and evidence for the reactive σbπ* state from transient absorption spectra

Abstract

From quantum yield and nanosecond flash photolysis data and UV–PE spectra it is concluded that metal-to-ligand charge transfer (MLCT) excitation of the complexes ReR(CO)₃(Prⁱ-dab)(R = Me, Et, Bn) only leads to efficient homolysis of the metal–alkyl bond if R = Et or Bn, when the reactive σ_bπ* state is close in energy to the MLCT states.