Boron Research Paper

1.1 Boron History & Overview:

Boron is an element of the periodic table belonging to the group 13. It is the only non metal present in its group. Boron has three valence electrons. It is capable of forming covalent bonds between atoms of similar nature to form polyhedral clusters. Boron has 2 stable isotopes in nature. i.e.11B (80.1%) and 10B (19.9%). Boron exists in bound state.

Figure1. Elemental form of boron

The history of boron is derived from almost 6000 years ago, when boron compounds were discovered. Borax was the first mineral to be discovered in the Ancient world. Boron compounds were used in gold soldering, as mummification materials, and more specifically in the fabrication of borosilicate glass. The first documented chemical

These clusters usually are associated with high negative charges. For example the general formula for an n vertex closed structure (closo) is [BnHn]2-, the more open borane structures have increasingly higher negative charges. They are formed by triangular faced polyhedral containing a BH unit for each vertex. When one of these vertices is substituted by a heteroatom, such as carbon, it gives rise to a family of heteroboranes like Carboranes.

In 1960´s the first carboranes were synthesized. Carboranes (“carbaboranes” in the formal nomenclature) are polyhedral boron-carbon molecular clusters that are stabilized by electron-delocalized covalent bonding in the skeletal framework. W.N. Lipscomb and H.C Brown´s research discovered that polyhedral boron clusters could be described as species having occupied orbitals and multicentric bonds in different resonant forms. It was also discovered that B-H units show great reducing effect over unsaturated organic compounds and hence could have an effect on organic

It is a sandwich of two [C2B9H11]2- (dicarbollide)clusters with a metal ion in the center. A broad range of interactions can be formed between metallacarboranes and their neighboring molecules. Metallacarboranes can be of two types, namely endo- and exo-metallacarboranes. A metal fragment is linked to the periphery of the carborane skeleton in exo-metallacarboranes, through B–H…M interactions. Metallacarboranes are artificial structures with distinct physicochemical properties, such as delocalization of cluster charge, high rigidity of the skeleton, lipophilicity and the ability to form so-called dihydrogen bonds. Di hydrogen bonds connect partially negatively charged hydrogen atoms bonded to electropositive boron atoms with the partially positively charged hydrogen atoms in organic