Observation of Aromatic B<sub>13</sub>(CO)<sub><i>n</i></sub><sup>+</sup> (<i>n</i> = 1–7) as Boron Carbonyl Analogs of Benzene
Rui‐Nan Yuan, Jiao-Jiao Chen, Qiang Chen, Qin-Wei Zhang, Hong Niu, Rui-Li Wei, Zhihong Wei, Xiao‐Na Li, Si‐Dian Li
Abstract
CO as a typical σ-donor is one of the most important ligands in chemistry, while planar B 13 + is experimentally known as the most prominent magic-number boron cluster analogous to benzene. Joint gas-phase mass spectroscopy, collision-induced dissociation, and first-principles theory investigations performed herein indicate that B 13 + reacts with CO successively under ambient conditions to form a series of boron carbonyl complexes B 13 (CO) n + up to n = 7, presenting the largest boron carbonyl complexes observed to date with a quasi-planar B 13 + core at the center coordinated by n CO ligands around it. Extensive theoretical analyses unveil both the chemisorption pathways and bonding patterns of these aromatic B 13 (CO) n + monocations which, with three delocalized π bonds well-retained over the slightly wrinkled B 13 + moiety, all prove to be boron carbonyl analogs of benzene tentatively named as boron carbonyl aromatics (BCAs). Their π-isovalent B 12 (CO) n ( n = 1–6) complexes with a quasi-planar B 12 coordination center are predicted to be stable neutral BCAs.