title: Peculiar All-Metal σ-Aromaticity of the [Au2Sb16]4-Anion in the Solid State.
abstract: Gas-phase clusters are deemed to be σ-aromatic when they satisfy the 4n+2 rule of aromaticity for delocalized σ electrons and fulfill other requirements known for aromatic systems. While the range of n values was shown to be quite broad when applied to short-lived clusters found in molecular-beam experiments, stability of all-metal cluster-like fragments isolated in condensed phase was previously shown to be mainly ascribed to two electrons (n=0). In this work, the applicability of this concept is extended towards solid-state compounds by demonstrating a unique example of a storable compound, which was isolated as a stable [K([2.2.2]crypt)]+salt, featuring a [Au2Sb16]4-cluster core possessing two all-metal aromatic AuSb4fragments with six delocalized σ electrons each (n=1). This discovery pushes the boundaries of the original idea of Kekulé and firmly establishes the usefulness of the σ-aromaticity concept as a general idea for both small clusters and solid-state compounds.
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Changchun, Jilin, 130022, China.|Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT, 84322-0300, USA.
authors.forename: Ivan A
authors.identifier: 0000-0003-2663-3685
authors.initials: IA
authors.lastname: Popov
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Changchun, Jilin, 130022, China.
authors.forename: Fu-Xing
authors.initials: FX
authors.lastname: Pan
authors.affiliation: Shanxi University, Institute of Molecular Science, Taiyuan, China.
authors.forename: Xue-Rui
authors.initials: XR
authors.lastname: You
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Changchun, Jilin, 130022, China.
authors.forename: Lei-Jiao
authors.initials: LJ
authors.lastname: Li
authors.affiliation: Euskal Herriko Unibertsitatea (UPV/EHU) Donostia International Physics Center (DIPC), Euskadi, Spain.|IKERBASQUE Basque Foundation for Science, 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, Changchun, Jilin, 130022, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
authors.affiliation: Shanxi University, Institute of Molecular Science, Taiyuan, China.
authors.forename: Hua-Jin
authors.initials: HJ
authors.lastname: Zhai
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Changchun, Jilin, 130022, China.|State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China.
authors.forename: Zhong-Ming
authors.initials: ZM
authors.lastname: Sun
authors.affiliation: Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT, 84322-0300, USA.
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Boldyrev
keywords: Zintl anions; all-metal compounds; aromaticity; chemical bonding; structure elucidation