Magnetically induced current density in triple-layered beryllium–boron clusters

Abstract

Magnetically induced current densities were used to examine the aromatic character of two charged Be–B clusters, Be₆B₁₀²⁻ (1) and Be₆B₁₁⁻ (2). The current densities were computed by means of the diamagnetic-zero variant of the continuous transformation of the origin of the current density (CTOCD-DZ) method. It has been shown in previous studies that 1 and 2 have a triple-layered structure in which a B₁₀/B₁₁ central ring is sandwiched between two Be₃ rings. The current density calculations for the examined Be–B clusters revealed their double aromatic nature, which arises from the presence of two orthogonal, cyclically delocalized electronic subsystems within these molecules. The pattern of the current density distribution in the triple-layered Be–B clusters was found to be analogous to the one in the monocyclic C₁₀ cluster, which is a prototypical double aromatic system. The present study demonstrated that the current-density-based analysis provides much more information about the aromatic nature of the studied molecules than that based on the nucleus independent chemical shifts (NICS) index.