The photolysis of MoCl4(MeCN)(2) in MeCN in the presence of small amounts o
f H2O proceeds according to the equation (MoCl4)-Cl-IV. H2O --> (MoOCl4)-O-
VI + H-2. It is suggested that a ligand field excited state of MoCl4(H2O)(n
), which is initially populated by light absorption, is deactivated to a re
active metal-to-ligand (Mo-IV --> H2O) charge transfer state.