A theoretical study of interaction between dinitrogen and single transition-metal centers Mo, Fe and V

Abstract

Complexes of the transition metal-containing model compounds with dinitrogen (N-2)M(NH2)(3)(NH3) and (N-2)M(SH)(3)(NH3)(-OCH2COO-) [M=Mo,V, Fe] were studied by the density functional theory. The relative energetics of the reduction of N2 to ammonia by the proton-electron transfer to the dinitrogen derivative was predicted. The calculated results show that there is a strong interaction between the Mo center and dinitrogen and the V center dot center dot center dot NN interaction is relatively weak, whereas the Fe center cannot bind N-2. The homocitrate ring opening in the simplified Mo-containing fragment in the FeMoco was predicted to be manipulable by controlling the spin multiplicity and oxidation state of the transition metal complex. The present results from both models indicate that the Mo is the most efficient active site for the dinitrogen binding and reduction among the single transition-metal centers Mo, V and Fe.