Syntheses, Structures And Properties Of Polyoxomolybdates Constructed By Nitrogen-containing Carboxylic Acid

The dominating research of this dissertation is about synthesis about compounds. Here we mainly selected different nitrogen-containing carboxylic acid ligands, reacting with sodium molybdate or ammonium heptamolybdate. Finally several original polyoxomolybdates were successfully synthesized by changing the reaction conditions. These polyoxomolybdates were further characterized by elemental analyses, IR spectra, UV spectroscopy, cyclic voltammograms, X-ray powder diffraction, thermogravimetric analyses, X-ray photoelectron spectra. Photochromic property of some compounds were also studied.This thesis contains:1. Two members of phosphomolybdates:Cs2H3[HPMo6021(02CC6H4NH2)3]·6.5H20(1) (C3N2H5)4H[HPMo6O21(O2CC6H4NH2)3]·6H2O(2) and one arsenomolybdate (NH4)6[AsM06O21(02CC6H4NH2)3]·3H2O(3) have been obtainted successfully in aqueous solution. Compounds 1-3 are homogeneous. The all three compounds have fluorescent signals.2. One phosphomolybdate and one arsenomolybdate have been got in aqueous solution: Cs8H2[(HPMo6O21)2(HPO3){C5H3N(CO2)2}2]·7.5H2O(4) and (NH4)7H10(AsMo6O21)3 {C5H3N(COO)2}4]·20H2O(5). These two compounds have different structures. Both of them have photochromism.3. By using glycine as reactants, one phosphomolybdate Na5[HPMo6O21(C2O2NH4)3]·8H2O(6) has been successfully obtainted in aqueous solution. Compound 6 can form one-dimensional chain framework, and it has photochromism.4. A novel arsenomolybdate (C3N2H5)6(As4MogO33)·4H2O(7) has been synthesized in aqueous solution. Compound 7 has isolated structure, containing an novel anionic [As4MogO33]6-, and its solid powder has photochromism.