THE METALLIC FACE OF BORON

This chapter discusses the metallic face of boron. The properties of the element are reviewed and an idea of the relationship of boron to the other elements in terms of metallic character is presented. The chapter presents structural evidence delineating the similarities and differences of borane and transition metal species. Pertinent examples from metallaborane chemistry demonstrate real bridges between the two distinct areas. Both discrete and solid state systems are discussed in the chapter and the transition metal borides constitute bridges in the latter case. Despite real differences, because of the differing electronic structures of the atoms, there are a considerable number of similarities between the structural elements of the discrete complexes and the repeating units in the solid state. This theme receives further emphasis in a discussion of discrete transition metal borides that constitute links between molecular species and solid state structures with extended bonding networks. The chapter presents a brief discussion on how such discrete metallaboranes provide a logical preparative approach to solid state materials containing transition metals and boron. © 1990 Academic Press Inc.