Synthesis,Characterization And Properties Of Metal Complexes With 2,3-Dihydroxyterephthalic Acid

As one of the organic-inorganic hybrid materials,metal coordination polymers,especially metal organic frameworks,play an important role in catalysis,gas separation and storage,magnetism,fluorescence detection,chemical sensing,drug release and gas adsorption and desorption.Among them,novel and flexible coordination organic ligands,unique metal coordination centers and different experimental conditions affect the structure and properties of the obtained complexes,and organic ligands play a decisive role in these effects.Therefore,the rational design and selection of the corresponding organic ligands is of great significance for the synthesis of complexes,especially for the synthesis of functional complexes.In this thesis,2,3-dihydroxyterephthalic acid(H4DTPA)is selected as oxygen-containing ligand,together with bipyridines and flexible imidazoles introduced as nitrogen-containing ligands.A series of metal coordination polymers are synthesized by hydrothermal methods,and the corresponding structural analysis and characterization and properties are studied.In chapter 1,the applications of metal complexes in the fields of gas separation and storage,chemical induction and fluorescence recognition and so on are mainly introduced,and the basis and significance of this thesis are expounded.In chapter 2,six complexes of three transition metal ions(Cd2+,Zn2+,Ni2+)with H4DTPA and bipyridine ligands are introduced,containing[Cd(H2DTPA)(4,4’-mbipy)]n(2a),[Cd(H2DTPA)(2,2’-bipy)]n(2b),[Cd(H2DTPA)(4,4’-bipy)]n·2nH2O(2c),[Zn(H2DTPA)(4,4’-mbipy)n](2d),[Ni(H2DTPA)(5,5’-mbipy)(H2O)2]n·0.75nH2O(2e),[Ni(H2DTPA)(4,4’mbipy)2](2f),the X-ray diffraction results indicate that 2a,2d present 2D layer structure;2b,2c display 3D network fashion;2e shows a folded-1D chain,2f is a mononuclear architecture,and 2e,2f forming 3D supramolecular structure by the interaction of hydrogen bonding.In chapter 3,five cadmium(Ⅱ)transition metal complexes with H4DTPA and flexible imidazole ligands are synthesized as followings:[Cd(H2DTPA)(1,2-bix)n·nH2O(3a),[Cd(H2DTPA)(1,2-mbix)]n(3b),[Cd(H2DTPA)(1,3-bix)0.5(H2O)]n(3c),[Cd(H2DTPA)(1,4-mbix)(H2O)]n(3d),[Cd(H2DTPA)(1,3-bix)n·nH2O(3e),the fluorescence investigation of 3a-3e towards 1,4-DNB,1,3-DNB,2-NP,NB,4-NCB,4-BNAP are carried out.The results shows that the quenching percentage of 3b on 4NCB proves 56.89%,the lowest detection concentration is 1.09×105mol·L-1;and that 3e on 2-NP is 58.74%,the lowest detection concentration of 3e turns out to be 1.49×10-4mol·L-1.In chapter 4,three kinds of polynuclear metal complexes based on H4DTPA and cadmium or zinc acetates are presented,including[Cd4(HDTPA)2(H2DTPA)(dpp)2]n(4a),[Cd4(HDTPA)2(H2DTPA)(btmb)2]n·nH2O(4b),{[Zn9(OH)2(DTPA)4(H2O)]+(2A-5mpy)}n(4c).The fluorescence detection of nitro explosives such as 1,4-DNB,1,3-DNB,2NP,NB,4-NCB,4-BNAP and organic acids including 2,6pyridinedicarboxylic acid(PBDC),2-picolinic acid(PCA),nicotinic acid(NCA),isophthalic acid(IPTA),phthalic acid(PTA),terephthalic acid(TPTA),benzoic acid(BCA),1,3,5-benzenetricarboxylic acid(BTA)salicylic acid(SCA)towards these compounds are also studied.The results of fluorescence test indicate that 4a,4b towards nitro explosives and small molecular organic acids proves to be quenched or promoted,which provides ideas for the study of subsequent fluorescence recognition applications.In chapter 5,in situ synthesis of five cuprous complexes with H4DTPA and nitrogenous ligands has been carried out under hydrothermal conditions,containing[Cu4Cl4(2,2-bipy)2](5a),[Cu2Cl2(phen)]n(5b),[CuCl(mtdm)]n(5c),[Cu4Cl4(btmb)2]n(5d),[CuBr(btmb)0.5]n(5e).The complexes are determined by X-ray single crystal diffraction,powder diffraction,infrared spectroscopy,thermogravimetric analysis and solid fluorescence properties.