Theoretical study of different haptophoric nature 3-penten-2-one complexes with iron and Group 6B metals

Complexes η2-(3-penten-2-one)M(CO)5 and η4-(3-penten-2-one)M(CO)4 were studied theoretically and experimentally to clarify the changes occurring in geometrical and electronic structure of oxo dienes within π-complexes of metals (M = Fe, Cr, Mo, W). It is shows that upsetting of conjugation in hetero-diene in the course of its interaction with metallocenter is the main reason for the change in reactivity of oxodienes within π-complexes. For both types of π-complexes the degree of system C=C-C=O planarity upsetting increases monotonously with increase in complexing agent atom radius