Pure Appl. Chem., 2003, Vol. 75, No. 4, pp. 435-443
doi:10.1351/pac200375040435
Carbenes. Pincers, chelates, and abnormal binding modes*
R. H. Crabtree
225 Prospect St, New Haven, CT 06520-8107, USA
Abstract:
Routes to pincer and chelate carbene complexes of Pd, Rh, and Ir include double geminal CH activation, metallation, and CH activation. Abnormal binding via imidazole C5 can occur, and ion pairing can strongly influence C2 vs. C5 binding. Prior ligand binding via pyridine N before metallation is not essential. Computational methods are used extensively, for example, to compare N vs. C binding in imidazole. The possibility of C binding by histidine in metalloenzymes is discussed.
*Plenary lecture presented at the XXth International Conference on Organometallic Chemistry (ICOMC), Corfu, Greece, 7-12 July 2002. Other presentations are published in this issue, pp. 421-494.