ABSTRACT
Boron, the only nonmetal among the elements of Group 13 of the periodic table, exhibits a very unique combination of properties. A very high melting point of 2076°C, low density, a Knoop hardness of 2160-2900, and high Young’s modulus make it very useful in a diverse range of industrial applications.1 The electron-de™cient nature of elemental boron and the presence of vacant p-orbitals lead to the unusual structural complexity of boron-based materials. These characteristics of boron have prompted its existence in clusters containing delocalized multicenter bonding as seen in the B12 icosahedrons. Moreover, it may cause an increase of ligancy even to its adjacent atoms in the boroncontaining compounds. The interesting features of pure boron and boron-based materials have made boron chemistry structurally varied and exciting.
