Hits:

Indexed by:期刊论文

Date of Publication:2014-02-14

Journal:DALTON TRANSACTIONS

Included Journals:SCIE、EI、PubMed、Scopus

Volume:43

Issue:6

Page Number:2488-2498

ISSN No.:1477-9226

Abstract:Three new architectures based on Anderson-type polyoxometalates, (3-H(2)pya)[(3-Hpya)(2)Ag][AgAlMo6-H6O24].3H(2)O 1, HNa2[(3-pya)(3-Hpya)Ag] (2)[AlMo6H6O24] .8H(2)O 2 and [(3-Hpya)(2)Ag][(H2O)(2)Ag](2)[AlMo6H6O24].2H(2)O 3 (3-Hpya = 3-(3-pyridyl) acrylic acid), have been synthesized at the different pH values and characterized by elemental analysis, IR spectroscopy, TG analysis, powder X-ray diffraction and single crystal X-ray diffraction. Compound 1 was obtained at lower pH value (2.50), and represents a 3D hostguest compound containing the Ag-3-Hpya coordination complex guest and the 3D [AgAlMo6H6O24](2)-host. The host framework exhibits a 4-connected diamond topology, and is constructed from [AlMo6H6O24]3-clusters connected by Ag+ cations. When the pH value was increased slightly, compound 2 was obtained with a 1D chain structure built up of Anderson polyoxoanions, Ag-3-Hpya coordination complexes and binuclear sodium clusters. By further increasing the pH value (3.50), compound 3 was isolated as a 2D network in which [AlMo6H6O24]3-clusters are linked together by Ag+ cations and Ag-3Hpya coordination complexes. Their structural differences reveal that the pH value of the reaction system is the key factor influencing the structure and topology of three compounds. The UV-visible-NIR diffuse reflectivity spectra of 1-3 show that they can be regarded as a wide gap semiconductor. Furthermore, the pyrolysis of 1-3 produces three nanocomposites 1'-3' composed of silver microparticles dispersed in the metal oxides. The photocatalytic properties of 1'-3' have been investigated.