Syntheses,Structures And Properties Of Polyoxometalate-based Metal-organic Frameworks Constructed By Cu/Ag

Polyoxometalate-based metal-organic frameworks(POMOFs)is a kind of organic-inorganic hybrid compounds containing polyoxometalate(POM)units with open network structures,which solve the problem of strong solubility and easy aggregation of POMs in water and greatly expand the application range.Due to their novel structures and advanced performance,such compounds have gained the attention of researchers and become a hot research project in the field of POM chemistry.In this master degree thesis,different N-donor and bifunctional organic ligands were selected and assembled with Cu/Ag and classic Keggin/Dawson polyanions under hydrothermal conditions.Three series of POMOFs were successfully synthesized and systematically characterized by single-crystal X-ray diffraction structure and so on.Besides,some of the tittle compounds were further investigated the properties of catalysis and adsorption of organic dyes.The research contents of this thesis are as follows:?.Two kinds of 3D frameworks 1,2,which comprise of Dawson/Keggin type polyanions and 2-pyrazinecarboxylic acid(pzc)were successfully prepared.Notably,the second ligand pyrazine(pz)in the compound 1 is formed by the decarboxylation of pzc ligand in situ.Compound 1 can be stably present in air and the aqueous solution of pH = 1-12,and was firstly employed as a highly efficient heterogeneous catalyst for the oxidation of alcohols,which shows 97%yield with TOF of up to 9690 h-1.H[Cu?5Cu?(pzc)2(pz)4.5{P2W18O62}·6H2O(1)[Cu?4(H2O)2Cu?2(pzc)4{SiW12O40}]·H2O(2)?.Using 1,2,4-triazole(trz)as ligand,two cases of POMOFs constructed of {Cu6(trz)6}macrocycle 3,4,two kinds of {Cu4Cl(trz)4} macrocycle-based POMOFs 5,6,and a Dawson-type based POMOF 7 with helical structure were isolated.Furthermore,compounds 3-6 showed high conversion and selectivity for the oxidation of alklbenzenes.Compound 7 possesses the highest coordination number of Dawson-type polyanions reported so far,and is capable of efficiently adsorbing the cationic dye methylene blue(MB)at room temperature.[Cu?6(trz)6{PW12O40}2](3)[Cu?3(trz)3{PMo12O40}](4)H[Cu?12(trz)8Cl2{PW12O40}](5)[Cu?12(trz)8(Cl{PMo12O40}](6)H[Ag10(H3trz)5(H2trz)2(trz){P2W18O62}]·5H2O(7)?.Three non-interpenetrating POMOFs 8-10 were successfully synthesized using pz as a ligand.These three compounds not only exhibit a variety of structural features,but also effectively adsorb MB dyes,of which compound 8 works best.[Ag5(pz)5{PW12O41}(OH)2]·2.5H2O(8)[Ag6(H2O)(pz)7{P2W18O62}]·3H2O(9)[Cu?3(pz)3(PMo12O40}·H2O(10)...