DFT studies on the mechanism of reactions between N2O and CP2M(η2-alkyne) (M = Ti, Zr)

DFT calculations have been carried out to study the activation of N2O by the transition-metal alkyne complexes CP2M(eta(2)-alkyne) (M = Ti, Zr). The mechanism for the formation of the five-membered metallacyclic complexes CP2M(RC=CR'NN(O)), which were obtained directly from the reactions of N2O with the metal alkyne complexes, and the conversion of the five-membered metallacyclic complexes CP2M(RC=CR'NN(O)) via N-2 loss to the oxametallacyclobutene complexes CP2M(RC=CR'O) have been investigated in detail. An effort has been made to understand how the kinetically inert N2O can be activated. We concluded that N2O is best activated by metal fragments that possess high capability of :pi-back-bonding interactions with the pi* orbitals of N2O.