New perspectives in the tailoring of hetero (bi- and tri-) metallic alkoxide derivatives

Metal alkoxides containing more than one sort of metallic element are predominantly known in the field of heterobimetallic derivatives. In order to pass to heterotrimetallic homoleptic alkoxides bimetallic alkoxides have to be prepared which are at the same time heterobimetallic and heteroleptic. They serve as starting materials in salt elimination reactions leading to heterotrimetallic homoleptic alkoxides. The structural entity serving as a building block in these reactions must be kinetically stable in order to survive in the synthetic procedures. Besides heterotermetallic alkoxides, heterobimetallic alkoxides with halides and cyclopentadienyl as ancillary ligands and transition metal complexes of new mixed-metal alkoxy derivatives are presented. Besides the syntheses and the structural characterization reactivity, spectral aspects in view of dynamic or static structures and applications of hetero(bi- and tri-)metallic alkoxides are discussed. (C) 1997 Elsevier Science Ltd, All rights reserved.