Boron Hydrides and Nanostructured Boron Materials

Boranes are hydrides of boron in which B–H groups occupy the apices of electron-deficient clusters. The term “electron deficient” arises from the fact that boron has more valence orbitals than it has valence electrons. The consequence of this imbalance is that the clusters are stabilized by extensive multi-centered bondings. The relationships between cage structures and the number of cage electrons are discussed for boranes and their extension to heteroboranes, where one or more BH units are replaced by isolobal main group or transition metal moieties. General synthetic methods and reactivities of the heteroboranes are also discussed. On the other hand, boron nanomaterials are a new class of materials emerged over the past two decades due to immense development in the field of nanotechnology. These materials are very useful in diverse applications including electronics, energy, space, and biomedicine. A description of different boron and boron-based nanomaterials along with their applications are included in this article. Keywords: boranes; carboranes; polyhedron; cages; nomenclature; multicentered-bonding; boron nanomaterials; nanotechnology; borospherene