title: [Synthesis and spectroscopy of K7[P2Mo4W13M(H2O)O61] (M= Cr, Fe) and their organic composite materials].
abstract: The Dawson heteropoly complexes K7[P2Mo4W13M(H2O)O61] (M= Cr(1), Fe(2)) and their organic composite materials formed by (E)-N-butyl-4-(2-(4'-dimethylaminophenyl)ethenyl)pyridinium cation and compound 1 (or 2) with the stoichiometry of (C19H25N2)(6)K3[P2Mo4W13MO62](M=Cr(3), Fe(4)) were synthesized and characterized by elemental analyses, thermogravimetric and differential thermal analyses, and IR, UV-Vis, solid diffuse reflectance UV-Vis-near IR, X-ray photoelectron and fluorescence spectroscopy. The results of spectra show that compounds 1 and 2 have Dawson structure, inorganic-organic composite materials are formed between the hemicyanine cations and the heteropoly anions, and the charge transfer occurs from the hemicyanine cations to the heteropoly anions in 3 and 4 complexes. The interaction between the hemicyanine cations and the heteropoly anions in the solid powder is stronger than that in the fluid solution. The compounds reported in this paper are interesting as nonlinear optical materials.
authors.affiliation: Department of Chemistry, Beijing Normal University, China.
authors.forename: Xiao-juan
authors.initials: XJ
authors.lastname: Hu
authors.forename: Li-hua
authors.initials: LH
authors.lastname: Gao
authors.forename: Ke-zhi
authors.initials: KZ
authors.lastname: Wang