Fluxional Behaviour of Group 9 Metal Carbonyl Clusters

Abstract

The site exchange processes of carbonyl ligands in homo- and hetero-metallic dodecacarbonyls of Ir and Rh and their derivatives take place by bridge opening and closing of CO's involving three or four metal atoms, and by rotation of terminal CO's about the apical metal centre. Substitution of Ir by Rh in the basal face of the metal framework slows down the first two processes and accelerates the third one, reflecting a significantly more electropositive character of Ir relative to Rh.