Benzonitrile hydrolysis catalyzed by a ruthenium(II) complex

FAGALDE, FLORENCIA; LIS DE KATZ, NOEMÍ D.; KATZ, NÉSTOR E.

JOURNAL OF COORDINATION CHEMISTRY

Taylor & Francis

Lugar: Abingdon; Año: 2002 vol. 55 p. 587 - 593

0095-8972

The rate constant for the basic hydrolysis of benzonitrile (PhCN) to benzamide (PhCONH2) in the [RuII(tpy)(bpy)] moiety (tpy = 2,2'-6':2"-terpyridine, bpy = 2,2?-bipyridine)  (kOH= 3.7x 102 M-1 s-1) is 5x103 times higher than that of the free ligand and two times higher than that corresponding to the analogous acetonitrile complex. This effect is unusual for a transition metal in the (II) oxidation state, and can be attributed to the p-electron acceptor properties of both the polypyridyl ligands and the phenyl group. Since amides, being poor p-acceptor ligands, are rapidly released from the coordination sphere of ruthenium(II), the final product of this process is the [Ru(tpy)(bpy)(OH)]+ complex. The activation parameters for this nitrile hydrolysis have been determined and compare reasonably well with other values for similar reactions.