Chemical Bonding, Reactivity, and Viability of Large Boron Clusters

Abstract

Quantum chemical methods were employed to investigate the structure, bonding, properties, and viability of new inorganic fullerenes based on boron, with the archetypal boron buckyball B 80 . Two current approaches on large boron nanoclusters include the search for hollow and multiple shells cages. Large boron clusters have only been identified in silico. In this Chapter, we analyze the chemical bonding phenomenon of B 80 , the symmetry of both B 80 and B 80 + , the reactivity of B 80 toward nucleophilic or electrophilic reactants, and the aromaticity and the topological indices of viable boron fullerenes. The boron buckyball B 80 is isoelectronic with the Buckminsterfullerene C 60 and can react as an amphoteric species with both acids (e.g., BH 3 , AlH 3 ) and bases (e.g., NH 3 , PH 3 , N 2 H 4 ). Both I h -B 80 and B 80 + are unstable, and undergo a symmetry breaking via both pseudo-Jahn–Teller and Jahn–Teller effects. The ring current analysis shows that B 80 can conduct current better than C 60 and is slightly paramagnetic. A detailed analysis on chemical bonding in a large set of boron fullerenes with partially and totally capped pentagons points out the following key factors that are stabilizing boron buckyballs: omnicapping of pentagons, homogeneous distribution of caps, formation of B 10 motifs preferably fused to B 16 , isolation of empty hexagons and caps, and incorporation of patches of 2D boron sheets.