Dinitrogen Cleavage by a Three-Coordinate Molybdenum(III) Complex

Science  12 May 1995:
Vol. 268, Issue 5212, pp. 861-863
DOI: 10.1126/science.268.5212.861


Cleavage of the relatively inert dinitrogen (N2) molecule, with its extremely strong N≡N triple bond, has represented a major challenge to the development of N2 chemistry. This report describes the reductive cleavage of N2 to two nitrido (N3–) ligands in its reaction with Mo(NRAr)3, where R is C(CD3)2CH3 and Ar is 3,5-C6H3(CH3)2', a synthetic three-coordinate molybdenum(III) complex of known structure. The formation of an intermediate complex was observed spectroscopically, and its conversion (with N≡N bond cleavage) to the nitrido molybdenum(VI) product N≡Mo(NRAr)3 followed first-order kinetics at 30°C. It is proposed that the cleavage reaction proceeds by way of an intermediate complex in which N2 bridges two molybdenum centers.