Spherical Aromaticity of All-Metal [Bi@In8Bi12]3−/5− Clusters

Nikolay V. Tkachenko, Utah State University
Xiang-Wen Zhang, Nankai University, China
Lei Qiao, Nankai University, China
Cong-Cong Shu, Nankai University, China
Dmitriy Steglenko, Southern Federal University
Alvaro Muñoz-Castro, Universidad Autonoma de Chile
Zhong-Ming Sun, Nankai University, China
Alexander I. Boldyrev, Utah State University


The chemical bonding of Zintl clusters is still an evolving and hot topic in modern chemistry. In this paper we synthesized a novel [K([2.2.2]crypt)]4[In8Bi13] complex in a condensed phase. The quantum chemical calculations and X-ray data revealed that the compound consists of the 1:1 mixture of [Bi@In8Bi12]3− and [Bi@In8Bi12]5− clusters. To the date, those clusters are the largest binary clusters composed of In and Bi elements. Herein, we introduce a spherical aromatic description of chemical bonding for such clusters. We show through AdNDP, ELF, and induced magnetic field and quantitative NICS analyzes that both clusters are spherically aromatic which explains their high symmetry, stability, and peculiar magnetic properties. We believe that this work will help researchers in the further development and understanding of chemical bonding in Zintl clusters.