title: Observation of a metal-centered B2-Ta@B18-tubular molecular rotor and a perfect Ta@B20-boron drum with the record coordination number of twenty.
abstract: A tubular molecular rotor B2-Ta@B18-(1) and boron drum Ta@B20-(2) with the highest coordination number of twenty in chemistry are observed via a joint photoelectron spectroscopy and first-principles theory investigation.
authors.affiliation: Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China. junli@tsinghua.edu.cn.
authors.forename: Wan-Lu
authors.initials: WL
authors.lastname: Li
authors.forename: Tian
authors.initials: T
authors.lastname: Jian
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Hai-Ru
authors.initials: HR
authors.lastname: Li
authors.forename: Teng-Teng
authors.initials: TT
authors.lastname: Chen
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Luo
authors.forename: Si-Dian
authors.initials: SD
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Wang