Exploring aromatic character of three-dimensional hydrogen cluster with the B3LYP hybrid density functional theory method

Abstract

Density functional theory studies were performed on linear and three-dimensional (3D) highly symmetric hydrogen clusters with the target being to determine the existence of 3D aromaticity and the rules that are applied in conjunction with the number of σ-electrons to their stability. The relative energies of these 3D clusters were compared with the relative energies of linear clusters. It was demonstrated that the relative stability of 3D clusters alters with the changing number of σ-electrons, similar to planar cyclic polyenes. Therefore, it was concluded that the 3D aromaticity is present in these chemical systems. Aromatic rules that are applied for singlet planar molecular systems are applicable for triplet 3D systems and vice versa.