Study On Synthesis,Structures And Spectra Of Organic-Molybdenum Phosphate Clusters

Among the metal oxides, molybdenum phosphates are of great importance. The various connection modes between MoOe octahedra and PCU tetrahedra allow molybdenum phosphates to be structurally very diverse and to possess one-dimensional chains two-dimensional layers and three-dimensional network with tunnel. The organic groups, as contrast to that of phosphates or silicates, behave soft in geometry and strong coordination ability. They can, to some extent, control and modify the surface formation of inorganic metal oxides. As a result, organic component may assume a variety of structural or functional roles in the design of novel metal oxides. Organic-inorganic hybrids combine the merits of both one, and therefore have been the focus of recent studies.We carried out the study about hydrothermal synthesis of molybdenum phosphate, and intended to find the relationship between properties and structure. So far we had made achievements in such aspect:1. Synthesizing twelve novel metal oxides and employing X-ray single crystal diffractometer technology to determine their structures. Ten of these twelve compounds are organic-molybdenum phosphate:-5H2O (4)(H3NCH2CH2NH3)7-(4H30)-[Cu(HPO4)4(PO4)4Moi2O3o]-lH2O(6) (H3NCH2CH2NHCH2CH2NH3)2-H5- {Co0.5[(HPO4)2(PO4)2Mo6Oi5] } 4H2O (7) [Co(H3TEATA)]2{Coo.5[HP04(P04)3Mo60i5]}-3.5H20(8) (H3DEATA)-(H30)4-{Coi.5[(HP04)2(P04)2Mo60i5]}-0.5H20(9) (NH3CH2CH2NH3)4-Na3-(H30)11[NaMoI203o(P04)7(HP04)]-9.5H20(10) An unprecedented molybdenum phosphate and a novel cobalt phosphate: Na4-(H3O)-[Na(HP04)2(P04)4Moi8O49]-16H2O (11) Na2P2Co2O8 (12)Among these compounds, compound 1 and 2 possess isolating [(PO4)2MosOi5] cage, while compound 3 is rather novel whose [(PO4)2MosOi5] cages are linked into chains by Cu groups, and the other seven organic-molybdenum phosphates(compound 410) contain cluster of [(PO4)6Moi2O3o], five of which involve isolating [(PO4)6Moi2C>3o] cluster, the rest two display 1-D chain and 2-D layer structure, respectively. All ten organic-molybdenum phosphates display complicated hydrogen bonds.2. Employing IR, Raman, DRS, fluorescent spectra and TGA to characterize some compounds. In IR and Raman spectra, we ascribed the characteristic peaks of molybdenum phosphates to corresponding vibration frequencies and found the characteristic peaks are related to the structure. The LMCT bands about coordinated oxygen atoms to metal are also discussed, besides, we studied the fluorescent spectra of some solid compounds, their emission peaks differ slightly with the structure, and the fluorescent lifetime results show that several compounds have long lifetime. At last, thermal behavior of some compounds are discussed by TGA diagrams.3. Performing quantum chemistry calculation to evaluate their bonding properties.