Infrared and kinetic studies of Group VI metal pentacarbonyl amine compounds Academic Article uri icon

abstract

  • Compounds of the type M(CO)5amine, where M = Cr, Mo, and W, undergo thermal decomposition reactions to form M(CO)6 reaction products. The rate of reaction follows the first-order rate law: rate = k1[M(CO)5amine]. The rate constant k1, for a particular metal, was found to decrease as the pKa of the amine increased. This is consistent with the proposed dissociative mechanism which involves a cleavage of the metal-nitrogen bond in the rate-determining step. Compounds containing unsaturated amine ligands, such as pyridines, were observed to be much more stable than their pKa values would indicate. This is interpreted as resulting from a small amount of metal-nitrogen “back-bonding.” No correlation was observed between the nature of the metal-nitrogen bond, as indicated by the rate constant (k1) or pKa for the amine group, and the calculated CO stretching force constants. © 1972, American Chemical Society. All rights reserved.

altmetric score

  • 3

author list (cited authors)

  • Dennenberg, R. J., & Darensbourg, D. J.

citation count

  • 66

publication date

  • January 1972