Syntheses, Structures And Properties Of Metal-oxygen Clusters

This thesis mainly focuses on the syntheses, structures and properties of novelmetal-oxygen clusters (POMs). Under acid condition, choosing different reactionsystem, we have successfully hydrothermal synthesized33novel non-classical metal-oxygen clusters with novel structures and excellent properties. They were allsynthesized for the first time. The33compounds are as folows:1.[V16O39Cl][Fe(Phen)3]3·7.5H2O (1)2.[(HSiMo12O40)(H4,4’-bpy)2][(H4,4’-bpy)(H2O)2]·2H2O (2)3.[Cu2(4,4’-bpy)2][HPMo12O40]·(C5H6N2)(3)4.[(HSiW12O40)(H4,4’-bpy)2][(H4,4’-bpy)(H2O)2]·2H2O (4)5.[(SiW12O40)(H4,4’-bpy)4]·(4,4’-bpy)·2H2O (5)6.[H4SiW12O40](2,2’-bpy)4(6)7.[Cu3(4,4’-bpy)3][HSiW12O40]·Im (7)8.[Cu(Phen)(4,4’-bpy)(H2O)]2[PW12O40]·(4,4’-bpy)(8)9.[Mo8V7O42][Cu(2,2’-bpy)2]2[Cu(2,2’-bpy)]·2H3O (9)10.[H24,4’-bpy][PMo12Sb2O40]·6H2O (10)11.[Him]2[PMo12Sb2O40]·H2O (11)12.[H3(DABCO)2][PMo12Sb2O40]·2H2O (12)13.[Mn(phen)3][PMo12Sb2O40](13)14.[Cu(Phen)2]2[PMo12Sb2O40](14)15.[Cd(bpy)4(H2O)2][PMo12Sb2O40]·bpy·2H2O (15)16.{[PMo12Sb2O40][Cu(Im)2]2}·Im (16)17.{[PMo12Sb2O40][(Cd(Phen)2)2Cl]}(17)18.[Cu(Phen)2]4[Cu4I3(Phen)4][BW12O40]·3H2O (18)19.[Cu(Phen)2]4[Cu4I3(Phen)4][PW12O40]·3H2O (19)20.[Cu(Phen)2]4[Cu5Cl4(Phen)4][AlW12O40]·4H2O (20)21.[Cu(Phen)2]4[Cu5Cl4(Phen)4][PW12O40]·4H2O (21)22.[Cu(Phen)2]4[Cu5Cl4(Phen)4][BW12O40]·2H2O (22)23.[Cu(Phen)2]4[Cu5Br4(Phen)4][AlW12O40]·6H2O (23) 24.[Cu(Phen)2]4[Cu5Br4(Phen)4][PW12O40]·4H2O (24)25.[Cu(Phen)2]4[Cu5Br4(Phen)4][BW12O40]·8H2O (25)26.[HAlW12O40]][Co(Phen)2(H2O)]2·4H2O (26)27.[PW12O40][Ag4(bzmd)2](27)28.[Ag6(bzmd)2][SiW12O40](28)29.[Cu3(4,4’-bpy)3][PMo12O40]·(C5H6N2)(29)30.[HPW12O40][Cd(2,2’-bpy)3](2,2’-bpy)(30)31.[SiW12O40][Cd(2,2’-bpy)2]2(31)32.[Cu(Phen)2]2[Cu11Cl7(Phen)8][PW12O40])(32)33.{[PMo12V2O42][Cu(enMe)2][Cu(enMe)2(H2O)]}[Cu(enMe)2(H2O)](33)The transition metals, organic ligands and reaction system pH value on theinfluence of the reaction products were studied. On the bases of X-ray structuralanalyses, these compounds have been characterized by elemental analysis, IR, UV-Vis, EPR, fluorescence, X-ray photoelectron spectroscopy (XPS) and XRD. Thethermal analyses, electrochemistry and magnetism properties of some compoundshave been studied, which would take an important role in the explorations ofstructures and functions for the compounds. We will mainly discuss the former25compounds in this thesis.1. vanadium-oxygen clustersApplying in hydrothermal synthesis reactions, we synthesized a vanadium-oxygenclusters (compound1). Compound1is a novel compound based on [V16O39Cl]6-andtransition metal complexes (TMCs)[Fe(Phen)3]2+.[V16O39Cl]6-is the firstpolyoxoanion constructed from15VO5square pyramids and one VO4tetrahedron, itis novel that the VO4tetrahedron in the anion has two terminal oxygen atoms.Detailed analysis reveals that there exist a large number of strong O-H···O and C-H···O hydrogen bonding interactions in compound1. Through the hydrogen bondinginteractions a novel3-D supramolecular network structure is formed. The X-raysingle crystal analyses, elemental analysis, IR, XPS, UV-Vis and XRD have beenperformed on compound1. In addition, variable-temperature magnetic susceptibilitymeasurements of compound1reveals the feature of antiferromagnetic exchange.2. Molybdenum-oxygen clustersApplying in hydrothermal synthesis reactions, we synthesized two molybdenum-oxygen clusters (compound2-4). There contains two kinds of different1-D supramolecular chain structures in compound2. It is interesting that the two differentchains are interwoven into a novel2-D layer structure. Further analysis of compound2reveals that there also contains very complex C-H···O hydrogen bondinginteractions. These hydrogen bonds increased the stability of the crystal of2andconnect the POMs, organic ligands and water molecules into a3-D supramolecularstructure. A novel1-D chain structure is constructed from polyoxoanions, metal ionsand organic ligands connected together with POM-M-L-M-POM linking fashion incompound3. The X-ray single crystal analyses, elemental analysis, IR, XPS, UV-Vis,TG and XRD have been performed on compounds2-3. In addition, The fluorescenceand electrochemistry performance of compound3have been investigated.3. Tungsten-oxygen clustersApplying in hydrothermal synthesis reactions, we synthesized5Tungsten-oxygenclusters (compound4-8). Compounds4-6are examples of compounds based onorganic ligands and POMs. Through the hydrogen bonding interactions, compound4exhibits a supramolecular2-D layer structure, compound5exhibits a novelsupramolecular double chain structure, compound6contains a1-D chain structurewith two2,2’-bpy ligands as double bridges. Two novel POMMOFs are constructedfrom polyoxoanions, metal ions and organic ligands connected together with POM-M-L-M-POM linking fashion in compounds7-8. Compound7exhibits a novel3-Dframework structure, while compound8exhibits an unprecedented2-D layeredframework structure in that their TMCs are constructed from two different organicligands. These compounds have been characterized by X-ray single crystal analyses,elemental analysis, IR, XPS, TG, fluorescence, UV-Vis and XRD. In addition, Theelectrochemistry properties of compounds7-8have been investigated.4. bis-capped Keggin metal-oxygen clustersApplying in hydrothermal synthesis reactions, we synthesized9bis-capped Kegginmetal-oxygen clusters (compound9-17). Compound9represents example of bis-vanadium-capped Keggin molybdenum-vanadium polyoxoanion tri-supported mixed-valent transition metal coordination complex via both terminal-and bridge-oxygenatoms. Compounds10-12represent examples of1-D supramolecular chain structuresthrough the hydrogen bonding interactions based on {PMo12Sb2O40} and differentorganic moieties. Compounds13-15are compounds with discrete structuresconstructed from {PMo12Sb2O40} polyoxoanions and different transition-metal coordination fragments. It is interesting that the POMs in compounds13and14arearranged into a novel face centered lattice and a novel body centered lattice,respectively. Compound15is linked through the hydrogen bonding interactions into anovel3-D network structure. The most remarkable feature of16is that the novelanion [PMo12Sb2O40]2-is utilized as a multidentate chelating ligand, coordinating tofour [Cu(Im)2]+TMCs via terminal oxygen atoms and bridging oxygen atoms to yieldan unprecedented1-D chain structure. An unusual feature of17is that it contains anovel metal halide cluster {Cd(Phen)2]2Cl}3+, and the “butterfly” clusters acting asbridges interconnect the [PMo12Sb2O40]3-POMs into a novel chain structure. It is thefirst extended structure constructed from POMs [PMo12Sb2O40]3-, TMCs and halideions synchronously. These compounds have been characterized by X-ray singlecrystal analyses, elemental analysis, IR, XPS, TG, UV-Vis and XRD etc. In addition,variable-temperature magnetic susceptibility measurements of compound9revealsthe feature of antiferromagnetic exchange.5. Compounds based on polyoxometalates and metal halide clustersApplying in hydrothermal synthesis reactions, we synthesized8compounds basedon polyoxometalates and metal halide clusters (compounds18-25). The crystalstructures of compounds18-19are isomorphous and the metal halide clusters incompounds18and19are hepta-nuclear. The crystal structures of compounds20-25are isomorphous too, they represent examples of the novel compounds based onpolyoxometalates and ennea-nuclear metal halide clusters. Furthermore, there existchloride ions in compounds20-22, and the halide ions in compounds18-19and23-25are iodine ions and bromide ions, respectively. These compounds have beencharacterized by X-ray single crystal analyses, elemental analysis, IR, XPS, UV-Visand XRD. In addition, the thermal analyses of the compounds have been investigated.