Syntheses, Structures And Properties Of Compounds Based On Triethanolamine And Polyoxometalates

The aim of the thesis is the synthesis of novel organic-inorganic compounds based on triethanolamine (TEA) and polyoxometalates (POMs). The study on synthetic conditions and roles for these hybrid compounds and the exploration of relationships between structures of POMs and TEA are also carried out.Six novel organic-inorganic hybrid compounds have been synthesized in aqueous solution and structurally characterized by single X-ray diffractions, elemental analyses, XRD, IR, NMR,TG-DTA. The thermal stabilities and electrochemistry behavior of compounds have been studied.1. Three iso- and hetro-polyoxometalates containing protoned tea acting as counter cations have been synthesized and characterized based on the improvement of the traditional synthesis method: Na2(NH(CH₂CH₂OH)₃)5[HMo₃₆O112(H₂O)16]·67H₂O (1) [(CH₂CH₂OH)₃NH]2HPMo12O40·16H₂O (2) [(CH₂CH₂OH)₃NH]6P2Mo18O62·30H₂O (3)By the means of adjustment of pH of aqueous solution of compound (2), We obtain compound [(CH₂CH₂OH)₃N]4Na2HPMo12O40?22H₂O (4).2. In the self-assembly process, we obtain a organic-inorganic hybrid compound comprising of {Mo₃₆} and tea: Na2[NH(CH₂CH₂OH)₃]4{Mo₃₆O₁₁₂(OH₂)14[OHCH₂CH₂NH(CH₂CH₂OH)2]2}·72H₂O (5) Compound (5) is the second organic-inorganic compound based on {Mo₃₆} unit, however, it is the first time that organic components connect to {Mo₃₆} unit via covalent band.3. A compound was synthesized by the means of utilizing TEAH+ to trapping and stabilizing Dawson structure polyoxomolybdovanadate: [NH(CH₂CH₂OH)₃]6V2Mo18O62·ca.3H₂O (6)First, 1a is a novel example of polyoxomolybdovanadate with the unexpected composition of V/Mo = 2:18. Second, the introduction of transition metals to the center tetrahedra provide a new insight to furthermore understand the conventional Dawson structure. The synthesis of 1a raises the intriguing possibility of preparation of a family of Dawson type complexes containing transition metals which would likely also to be central hetero-atoms.