Regular Article

Structural evolution in boron-based clusters B₅Al_n^0/-/+ (n = 1–4): Al atoms transition from the periphery of the planar W-shaped B₅ ring to the vertex of the bipyramid^★

¹ Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education; Center for Computational Quantum Chemistry, School of Chemistry, South China Normal University, Guangzhou 510006, P.R. China
² Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China
³ School of Physics and Astronomy, University of Minnesota, 115 Union St. SE, Minneapolis, Minnesota 55455, USA

^a e-mail: glli@scnu.edu.cn
^b e-mail: Lmyang@hust.edu.cn

Received: 23 July 2020
Received in final form: 7 September 2020
Accepted: 10 September 2020
Published online: 1 November 2020

Abstract

The structures and properties of binary boron-aluminum B₅Al_n^0/-/+ (n = 1–4) clusters have been systematically explored using the density functional theory method at the B3LYP/6–311+G(d) level and the coupled cluster method at the CCSD(T)/6–311+G(2df)//B3LYP/6–311+G(d) level. Lowest-energy structures, stabilities, growth behaviors and chemical bonding of these clusters were analyzed. Our results show that when the number of doped Al atoms is one or two, the Al atoms are located at the periphery, and the host B₅ cluster preferentially forms a W-shape core, which is only slightly affected by the Al atoms. When there are three or four Al atoms, the B₅Al_n^0/-/+ (n = 3, 4) clusters have their lowest energy structures preferentially in capped bipyramid configurations. Neutral B₅Al_n (n = 1, 3) clusters are somewhat more stable than their neighboring n clusters, while anionic and cationic B₅Al_n^-/+ (n = 2, 4) clusters tend to be somewhat more stable. We also simulated the infrared (IR) spectrum and photoelectron spectroscopy (PES) of these clusters for future experimental comparison. Adaptive natural density partitioning (AdNDP) analysis shows that a variety of delocalized multicenter bonds appear in these clusters, which may enhance the stability of the clusters.