title: Eu3Co2In15 and KM2In9 (M = Co, Ni): 3D frameworks based on transition metal centered In9 clusters.
abstract: The title three compounds have been synthesized by solid state reactions at high temperatures, with excess indium as flux, and structurally characterized by single-crystal X-ray diffraction studies. Eu(3)Co(2)In(15) forms a new structure type and crystallizes in the tetragonal space group P4/mbm (No. 127), whereas KM(2)In(9) (M = Co, Ni) in the BaFe(2)Al(9) type crystallizes in the hexagonal space group P6/mmm (No. 191). Their structures all feature a three-dimensional anionic framework based on 1D [MIn(6)] single cluster chains composed of face-sharing [MIn(9)] clusters. In Eu(3)Co(2)In(15), two adjacent [CoIn(6)] single cluster chains form a [Co(2)In(11)] double cluster chain via corner-sharing In atoms as well as In-In bonds; the latter chains are further interconnected by additional indium atoms via In-In bonds into a complicated 3D framework, forming two types of tunnels along the c-axis, which are filled by the europium atoms. In KM(2)In(9), the [MIn(6)] single cluster chains are directly interconnected via corner sharing and exo In-In bonds into a 3D framework with the K(+) ions encapsulated in the 1D tunnels along the c-axis. Band structure calculations of three compounds based on density functional theory methods indicate that all three compounds are metallic.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Xiao-Wu
authors.initials: XW
authors.lastname: Lei
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Zhong
authors.forename: Long-Hua
authors.initials: LH
authors.lastname: Li
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Hu
authors.forename: Min-Jie
authors.initials: MJ
authors.lastname: Li
authors.forename: Jiang-Gao
authors.initials: JG
authors.lastname: Mao