DINUCLEAR AND TRINUCLEAR METAL-COMPLEXES OF DIBORAHETEROCYCLES

This chapter summarizes results on di- and trinuclear complexes. These results demonstrate that mixed-ligand complexes are stable, and most likely these di- and trinuclear “hybrid” complexes may be used for the formation of novel oligo- and polydecker complexes. The oligodecker complex chemistry of six-membered diboraheterocycles has only one example; the slipped tetradecker 18 with 2 as bridging ligand could be obtained. The organic π-ligands have played the leading role in the development of organometallic π-complex chemistry. However, examples of di- and trinuclear complexes of the carbacyclic n-systems have only been synthesized in the last decade. First, a short survey on di- and trinuclear metal complexes of hydrocarbon π -ligands is given. In addition an introduction to five-membered heterocyclic ligands, a summary of bifacially coordinated cyclopentadienyl ligands is also given in the chapter. © 1993, Academic Press Inc.