title: Synthesis, characterization, and crystal structures of two novel high-nuclear nickel-substituted dimeric polyoxometalates.
abstract: Two novel high-nuclear Ni-substituted polyoxometalates Na9K[Ni7(OH)4(H2O)(CO3)2(HCO3)(A-alpha-SiW9O34)(beta-SiW10O37)].5H3O.18H2O (1) and K6Na4[{Ni6(H2O)4(mu2-H2O)4(mu3-OH)2}(x-SiW9O34)2].17.5H2O (2) have been obtained by reaction of K(8)[gamma-SiW10O36] with NiCl2.2H2O in basic conditions. Compounds 1 and 2 all represent the first polyoxometalates substituted by seven and six Ni centers, respectively. Also, compound 1 exhibits a novel asymmetric dimeric structure, composed of [A-alpha-SiW9O34]10- and [beta-SiW10O37]10- units linked by a Ni7 cluster and three carbonates, which exhibit tri- and bidentate coordination modes in 1.
authors.affiliation: Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yangguang
authors.initials: Y
authors.lastname: Li
authors.forename: Enbo
authors.initials: E
authors.lastname: Wang
authors.forename: Xinlong
authors.initials: X
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Qin
authors.forename: Haiyan
authors.initials: H
authors.lastname: An