title: All-Metal Antiaromaticity in Sb4 -Type Lanthanocene Anions.
abstract: Antiaromaticity, as introduced in 1965, usually refers to monocyclic systems with 4n π electrons. This concept was extended to all-metal molecules after the observation of Li3 Al4 (-) in the gas phase. However, the solid-phase counterparts have not been documented to date. Herein, we describe a series of all-metal antiaromatic anions, [Ln(η(4) -Sb4 )3 ](3-) (Ln=La, Y, Ho, Er, Lu), which were isolated as the K([2.2.2]crypt) salts and identified by single-crystal X-ray diffraction. Based on the results obtained from the chemical bonding analysis, multicenter indices, and the electron-counting rule, we conclude that the core [Ln(η(4) -Sb4 )3 ](3-) fragment of the crystal has three locally π-antiaromatic Sb4 fragments. This complex represents the first locally π-antiaromatic all-metal system in the solid state, which is stabilized by interactions of the three π-antiaromatic units with the central metal atom.
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Min
authors.affiliation: Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT, 84322-0300 (U, SA.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Popov
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Fu-Xing
authors.initials: FX
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Lei-Jiao
authors.initials: LJ
authors.lastname: Li
authors.affiliation: Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) and Donostia International Physics Center (DIPC), P.K. 1072, 20080, Donostia, Euskadi, Spain.|IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Matito
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China. szm@ciac.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. szm@ciac.ac.cn.
authors.forename: Zhong-Ming
authors.initials: ZM
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Brown University, Providence, RI, 02912, USA.
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT, 84322-0300 (U, SA. a.i.boldyrev@usu.edu.
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Boldyrev
keywords: Zintl anions; antiaromaticity; antimony; chemical bonding analysis; lanthanocenes