title: The B35 cluster with a double-hexagonal vacancy: a new and more flexible structural motif for borophene.
abstract: Elemental boron is electron-deficient and cannot form graphene-like structures. Instead, triangular boron lattices with hexagonal vacancies have been predicted to be stable. A recent experimental and computational study showed that the B36 cluster has a planar C6v structure with a central hexagonal hole, providing the first experimental evidence for the viability of atom-thin boron sheets with hexagonal vacancies, dubbed borophene. Here we report a boron cluster with a double-hexagonal vacancy as a new and more flexible structural motif for borophene. Photoelectron spectrum of B35(-) displays a simple pattern with certain similarity to that of B36(-). Global minimum searches find that both B35(-) and B35 possess planar hexagonal structures, similar to that of B36, except a missing interior B atom that creates a double-hexagonal vacancy. The closed-shell B35(-) is found to exhibit triple π aromaticity with 11 delocalized π bonds, analogous to benzo(g,h,i)perylene (C22H12). The B35 cluster can be used to build atom-thin boron sheets with various hexagonal hole densities, providing further experimental evidence for the viability of borophene.
authors.affiliation: Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Li
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Tian
authors.forename: Hui
authors.initials: H
authors.lastname: Bai
authors.forename: Ya-Fan
authors.initials: YF
authors.lastname: Zhao
authors.forename: Han-Shi
authors.initials: HS
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Hua-Jin
authors.initials: HJ
authors.lastname: Zhai
authors.forename: Si-Dian
authors.initials: SD
authors.lastname: Li
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Wang