title: pH-dependent assembly of hybrids based on Wells-Dawson POM/Ag chemistry.
abstract: Four new hybrids based on the Wells-Dawson polyoxometalate [P2W18O62](6-) (P2W18), ([Ag(bipy)]2[P2W18O62]).2[H2bipy].4H2O (1), ([Ag(bipy)]4[P2W18O62]).2[Hbipy](2), K[P2W18O62].2.5[H2bipy].2H2O (3), and [P2W18O62] 2.[H2bipy]4.[Hbipy]4 .3H2O (4), were hydrothermally synthesized and structurally characterized by routine techniques and single-crystal X-ray diffraction. Compounds 1 and 2 are isolated at lower pH values. 1 represents a 3D (4,4)-net structure with NbO topology, in which the P2W18 clusters are modified by four Ag-N coordination polymeric chains, and 2 exhibits a 3D (3,4)-net structure with the (9(2).12)(8.10(4).12)(3(2).10(2).11(2))(3.6.10(2).12(2)) topology, in which Ag-bipy layers are intercalated by the dimer of P2W18 clusters in a staggering mode, and the P2W18 clusters show the highest coordination number to date. By increasing the pH value, compounds 3 and 4 are obtained as supramolecular compounds. Their structural differences reveal that the pH value of the reaction system is the key factor influencing the structure and topology of these compounds, which can be explained by the acid-base chemistry of the molecular building units and silver chemistry.
authors.affiliation: Key Laboratory of Polyoxometalate Science of Ministry of Education, Faculty of Chemistry, Northeast Normal University, Changchun, Jilin, 130024, P. R. China.
authors.forename: Jingquan
authors.initials: J
authors.lastname: Sha
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
authors.forename: Yaqan
authors.initials: Y
authors.lastname: Lan
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Su
authors.forename: Haijun
authors.initials: H
authors.lastname: Pang
authors.forename: Aixiang
authors.initials: A
authors.lastname: Tian
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Zhu
mesh_terms: D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D012834:Silver / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction; D000099294:Polyoxometalates
chemical_list: D046911:Macromolecular Substances; D012834:Silver; D017973:Tungsten Compounds; C102296:polyoxometalate I; D000099294:Polyoxometalates