Synthesis, Structure And Property Of Functional Polyoxovanadates

The aim of this thesis is the synthesis of new framework compounds on the basis ofpolyoxovanadates. The study on synthetic conditions and rules for these new compounds,topological analyses, and the exploration of relationships between structures and propertiesfor these new compounds are also carried out.Thirty-one new compounds have been synthesized on the basis of hydrothermal techniqueand/or mixed solventthermal synthesis methods and structurally characterized by elementalanalyses, IR, XRPD, TG and single crystal X-ray diffractions. The thermal stabilities,magnetic properties and electrochemical activities of these compounds have been studied.1. Twenty-one new compounds have been hydrothermally synthesized by virtue of ligandswith different configurations, transition metal ions and arsenic-vanadate oxides:[Cu(phen)][(AsO4)(V₃O₇)(H₂O)] (1)[Mn (1,10-phen)3]2[As8V14O42(H₂O)0.5]·1.5H₂O (2)[Zn(1,10-phen)3]2[As8V14O42(H₂O)0.5]·2.5H₂O (3)[Cd(2,2'-bipy)3]2[As8V14O42(H₂O)0.5]·2.5H₂O (4)[Zn(en)₂][(H₂O)Zn(en)₂As8V14O42(H₂O)]·H₂O (5)[(H₂O)Zn(1,10-phen)₂]2[As8V14O42(H₂O)]·4H₂O (6)[{(H₂O)Zn(2,2'-bpy)₂}{Zn(2,2'-bpy)₂}As8V14O42(H₂O)0.5]2-[{(H₂O)Zn(2,2'-bpy)₂-As8V14O42(H₂O)0.5}2{Zn(2,2'-bpy)₂}2]·3H₂O(7)[(H₂O)Zn(4,4'-bpy)]2[As8V14O42(H₂O)]·2H₂O (8)[Co(en)₂(H₂O)₂][Co(en)₂As8V14O42(H₂O)]·2.5H₂O (9)[Cu(en)₂]2[As8V14O42(H₂O)]·2.5H₂O (10)[Ni(Meen)3]4[Ni(Meen)₂{As8V14O42(NO₃)}2]·7H₂O (11)[Ni(en)₂(H₂O)₂]2[{Ni(en)₂(H₂O)}2As8V14O42(NO₃)][{Ni(en)₂}As8V14O42(NO₃)]·6H₂O (12)[{Ni(en)₂}4(4,4'-bipy)4{Ni(H₂O)₂}]2[As8V14O42(NO₃)]4·16H₂O (13)[Cd(phen)₂(en)]2[(phen)CdAs₈V₁₃O41(H₂O)]·H₂O·phen (14)[Cd(en)3][Cd(phen)(en)(H₂O)₂][(en)CdAs₈V₁₃O41(H₂O)]·H₂O (15)[Zn(Meen)₂]2[(4,4'-bipy)Zn2As₈V₁₂O40(H₂O)] (16)[Zn(en)₂(H₂O)][Zn(en)₂(4,4'-bipy)Zn2As₈V₁₂O40(H₂O)]·3H₂O (17) [{Zn(en)3}2Zn2As8V14O40(H₂O)]·4H₂O·0.25bpy (18)[Zn(en)3]2[Zn(bpp)(en)₂][Zn(en)₂(H₂O)][(bpp)Zn2As₈V₁₂O40(H₂O)]2·bpp·7H₂O (19)[Zn(en)₂]2[(bpe)₂Zn2As₈V₁₂O40(H₂O)] (20)[Zn2(en)5]{[Zn(en)₂][(bpe)HZn2As₈V₁₂O40(H₂O)]2}·7H₂O (21)Compounds 1contains an unprecedented V6O20(H₂O)₂ building blocks connected withAsO4 to form a ribbon which is decorated directly by [Cu(phen)]2+ fragments. The mainstructural feature of compounds 2¹2is the presence of [AsIII8VIV14O42] as inorganic buildingblock Compounds 2⁴are constructed of simple [M(phen)3]2+(M = Mn(2), Cd(3), Zn(4))fragments andα-As8V14O42. The anion cluster of compound 5is decorated by a singleterminal [(H₂O)Zn(en)₂]2+ group to form a [(H₂O)Zn(en)₂AsIII8VIV14O42(H₂O)]2- polyoxoanion,the other zinc ion coordinated to en ligands acts as counterion but is not bounded to the POM.The crystal of 6consists of a neutral bisupporting polyoxovanadate and several lattice atermolecules. compound 7, in which the neutral dimmer and neutral bisupporting motifs coexist,represents a new example of modified POMs. The two-dimensional neutral network of 8isconstructed from the [As8V14O42]4- clusters, transition metal coordination polymer chains[(H₂O)Zn(4,4'-bpy)] n2n+ and water molecules. Compound 9is constructed from onedimensionalanion chains {Co(en)₂}As8V14O42(H₂O)]2- and [Co(en)₂(H₂O)₂]2+ cations.Compound 10consists of a novel [Ni(Meen)₂{As8V14(NO₃)}2]8- polyanion dimmer, isolated[Ni(Meen)3]2+ cations and lattice water molecules. Compound 11is a undee chain constructedfrom the [As8IIIV14IVO42] anion clusters and [Cu(en)₂]2+ complexes. Compound 12isconstructed from the rarely [β-As8V14O42] clusters and Ni coordination complex fragments.The boxlike structure of compound 13is constructed from two [{Ni(en)₂}4(4,4'-bipy)4{Ni(H₂O)₂}]10+ fragments, pillared by four anionic clusters [AsIII8VIV14O42(NO₃)]5-clusters. Compounds 14and 15are constructed from organically modified cadmiumsubstitutedpolyoxovanadates and cadmium-organoamine subunits. Compounds 16 21areconstructed from organically modified zinc-substituted polyoxovanadates and incorganoaminesubunits. The electrochemical studies on these compounds and the magneticproperties of compounds 11, 13,14, 16and 21are also discussed.2. Nine new compounds with different dimensionalities have been hydrothermallysynthesized on the basis of the flexible organic ligands with metal salts in the presence ofpolyoxovanadates:Mn(Hbiim)₂V₄O₁₂ (22)Co2(biim)3V₄O₁₂·4H₂O(23)Cu2(biim)3V₄O₁₂ (24) [Ag(biim)]2V4O11 (25)Ag4(btx)4H2V10O28·2H₂O (26)Zn(btx)V₂O₆ (27)Cu(btx)V₂O₆ (28)Co2(btx)4V₄O₁₂ (29)Co3(btx)5(H₂O)V8O23 (30)Compound 22is a one-dimensional (1D) ribbon based on [V₄O₁₂]4- building blocks and{Mn(biim)₂}2+bridge groups. Compound 23is a rare case of a self-catenated "ilc" networkdisplaying an unusual 424·5·63 topology with the binuclear {Co2O4N6} units as eight-connectednodes. Compound 24is a 3D inclined hetero-catenated framework designed from two 2D sublayers,[Cu(biim)V₄O₁₂] and [Cu(biim)₂]. Compounds 25and 26represent the first examplesof polyoxovanadates linked by Ag-coordinated complexes. The 3D poly-(pseudo-rotaxane)-type framework of 25is composed of the 1D chainlike polyoxoanion [V4O11]2- entrainedwithin the three-dimensional framework of the {Ag(biim)}nn+ coordination polymer, whichcan be alternatively viewed as 3D two-fold interpenetrated framework. Compound 26iscomposed of the ladder like double-chain [Ag2(btx)₂H2V10O28]2-, which is penetrated by{Ag(btx)}22+ double chain in an inclined way to from the poly-(pseudo-rotaxane)-typearchitecture. Isomorphous materials 27and 28are composed of {M'V₂O₆} bimetallic oxidelayers pillared by the interlamellar btx ligands. Compound 29is a 4, 6-connected selfpenetratingframework based on [V₄O₁₂]4- building blocks and {Co(btx)₂}2+ 3D metal-organiccation polymer. Compound 30exhibits a novel three dimensional (3D) 4,6-conneted selfcatenatednet, which is constructed from novel [V8O23]6- building blocks and{Co3(btx)5(H₂O)₂}6+ 3D metal-organic cation polymer. The electrochemical studies on thesecompounds 22 30and the magnetic property of compound 30are also discussed.