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

        Monocyclic Bn rings can act as n-electron s-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 s-donors to construct star-like structures including BrBe6H6+ and TMrBe7H7q (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 s-donation and p-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 Ben layer, and the outer Hn layer, as well as the s–p double aromaticity. Importantly, three of the ten species, including BrBe6H6+, CurBe7H7, and AurBe7H7, were confirmed to be kinetically stable global minima, thereby providing promising targets for experimental preparations.