title: A multicentre-bonded [Zn(I)]8 cluster with cubic aromaticity.
abstract: Polynuclear zinc clusters [Znx] (x>2) with multicentred Zn-Zn bonds and +1 oxidation state zinc (that is, zinc(I) or Zn(I)) are to our knowledge unknown in chemistry. Here we report the polyzinc compounds with an unusual cubic [Zn(I)8(HL)4(L)8](12-) (L=tetrazole dianion) cluster core, composed of zinc(I) ions and short Zn-Zn bonds (2.2713(19) Å). The [Zn(I)8]-bearing compounds possess surprisingly high stability in air and solution. Quantum chemical studies reveal that the eight Zn 4s(1) electrons in the [Zn(I)8] cluster fully occupy four bonding molecular orbitals and leave four antibonding ones entirely empty, leading to an extensive electron delocalization over the cube and significant stabilization. The bonding pattern of the cube represents a class of aromatic system that we refer to as cubic aromaticity, which follows a 6n+2 electron counting rule. Our finding extends the aromaticity concept to cubic metallic systems, and enriches Zn-Zn bonding chemistry.
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Cui
authors.affiliation: Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084, China.
authors.forename: Han-Shi
authors.initials: HS
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jeffery T
authors.initials: JT
authors.lastname: Miller
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Energy Material Chemistry of the Ministry of Education, Tianjin Key Laboratory of Metal and Molecule Based Material Chemistry, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
authors.affiliation: Department of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li