Magnetically induced current densities in singlet and triplet disk-like boron clusters

Abstract

The disk-like boron clusters are among the most alluring boron cluster forms. Molecular orbital distribution in these clusters can be rationalized by means of the simple particle-ona-disk model. In this model, the molecular orbitals come by pairs except for m = 0 (no angular nodes). The calculated magnetically induced current densities revealed that the disk-like boron clusters in their singlet ground state with closed-shell configuration are aromatic. It was found that the disk-like boron clusters that are aromatic in their ground states remain aromatic in their lowest-lying triplet states when the number of valence electrons is increased or reduced by two electrons. In addition, if the lowest-lying triplet state in disk-like boron clusters is aromatic, this triplet state is the ground state for these species. Aromaticity of the studied disk-like boron clusters in their lowest-lying singlet and triplet state, with the exception of triplet 3B19- can be predicted based on Hückel and Baird’s rules.