Viable aromatic BenHn stars enclosing a planar hypercoordinate boron or late transition metal

摘要

Monocyclic B-n rings can act as n-electron sigma-donors to stabilize a non-classical planar hypercoordinate atom at ring center, forming wheel-like structures. Herein, we report that BenHn rings can also serve as n-electron sigma-donors to construct star-like structures including B (c) OBe6H6+ and TM (c) OBe7H7q (TM is a group 10=12 metal with q = -1, 0, and 1, respectively) by complying with octet or 18-electron rules. Electronic structure analyses show that these species are stabilized by the a-donation and pi-backdonation between the central atom and the peripheral BenHn ring, the favorable Coulomb attraction due to the negative-positive-negative charge population pattern on the central atom, the middle Be, layer, and the outer H-n layer, as well as the sigma-pi double aromaticity. Importantly, three of the ten species, including B (c) Be6H6+, Cu (c) Be7H7, and Au (c) Be7H7, were confirmed to be kinetically stable global minima, thereby providing promising targets for experimental preparations.