title: Boronyl as a terminal ligand in boron oxide clusters: hexagonal ring C(2v) B6O4 and ethylene-like D(2h) B6O4(-/2-).
abstract: Considerable recent research effort has been devoted to the development of boronyl (BO) chemistry. Here we predict three perfectly planar boron boronyl clusters: C2v B6O4 (1, (1)A1), D2h B6O4(−) (2, (2)B3u), and D2h B6O4(2−) (3, (1)Ag). These are established as the global-minimum structures on the basis of the coalescence kick and basin hopping structural searches and electronic structure calculations at the B3LYP/aug-cc-pVTZ level, with complementary CCSD/6-311+G* and single-point CCSD(T)/6-311+G*//B3LYP/aug-cc-pVTZ calculations for 2. The C2v B6O4 neutral cluster features a hexagonal B4O2 ring with two terminal BO groups. The D2h B6O4(−/2−) clusters have ethylene-like structures and are readily formulated as B2(BO)4(−/2−), in which a B2 core with double bond character is bonded to four terminal BO groups. Chemical bonding analyses show that B6O4 (1) possesses an aromatic π bonding system with three delocalized, six-centered π bonds over the hexagonal ring, rendering it an inorganic analogue of benzene, whereas the B6O4(−/2−) (2 and 3) species closely resemble ethylene in terms of structures and bonding. This work provides new examples for the analogy between boron oxides and hydrocarbons.
authors.affiliation: Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China. hj.zhai@sxu.edu.cn lisidian@sxu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Ying-Jin
authors.initials: YJ
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Bai
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Gao
authors.forename: Hai-Ru
authors.initials: HR
authors.lastname: Li
authors.forename: Hua-Jin
authors.initials: HJ
authors.lastname: Zhai
authors.forename: Si-Dian
authors.initials: SD
authors.lastname: Li