Non-local electronic perturbations of metal-carbonyl bonds

Abstract

Metal-carbonyl bonds, as found for carbon monoxide either liganded to metalloporphyrins or chemisorbed onto metal surfaces, are discussed. These two classes of systems are compared with emphasis on short range vs. long range perturbations of the vibrational bands, v _MeC and v _CO. It is concluded that metalloporphyrins serve as models for terminal bonding on metal surfaces and that data obtained for carbonyl-hemes enable the isolation of non-local electronic effects, which are much discussed in connection with alkali promotors coadsorbed with CO on metal catalysts.