Synthesis,structures And Properties Of Functional Coordination Polymers Based On Benzothiadiazole Primitive

Because of the characteristics of high crystallinity,adjustable optical properties,strong adsorption affinity,and stable magnetic properties,coordination polymers are widely used in many fields such as gas adsorption and separation,heterogeneous catalysis,chemical sensing,magnetism and proton conduction,which have attracted attention from many researchers.In this thesis,functional ligand 4,7-bis(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole(DDBD)was synthesized by using 2,1,3-benzothiadiazole(BTD)as the primitive,and 12 functional coordination polymers with different structures have been obtained by using DDBD and different aromatic carboxylic acids.Their structures were characterized by X-ray single crystal diffraction,infrared spectroscopy,and X-ray powder diffraction.The effects of auxiliary ligands,metal ions and synthetic conditions on coordination polymers are summarized,and some coordination polymers have been studied in terms of fluorescence,magnetic properties and proton conductivity.The main research contents are as follows:1.Using DDBD and different linear aromatic carboxylic acid,seven new transition metal(Zn^II,Co^II and Cd^II)coordination polymers with different structures were obtained by solvothermal method.Their crystal structures and thermal stabilities as well as the fluorescence properties of DDBD and coordination polymer 4 were studied in detail.Fluorescence experiments show that DDBD can recognize ethylenediamine(EDA),triethylamine(TEA),N,N,N',N'-tetramethylethylenediamine(TMEDA),Mn O₄^-and Cl O^-with high selectivity and sensitivity through the fluorescence quenching,which is the first fluorescent sensor for the selective recognition of TMEDA.4 has high selectivity and sensitivity toward Mn O₄^-via fluorescence quenching,and can be used as a potential fluorescence sensor with fluorescence quenching effect on Mn O₄^-.2.Five new coordination polymers with different structures were prepared by using isophthalic acid(H₂IP),trimesic acid(H₃BTC),5-aminoisophthalic acid(H₂AIC),5-methoxyisophthalic acid(H₂MIA)with DDBD.The properties of coordination polymers 10 and 11 derived from H₂AIC have been studied in detail.Fluorescence experiments show that 11 can simultaneously selectively identify EDA,Fe³⁺and Al³⁺and has a lower detection limit via fluorescence enhancement.11 can be used as a potential multifunctional fluorescence sensor for identifying EDA,Fe³⁺and Al³⁺.Magnetic studies suggest that weak ferromagnetic coupling between the adjacent Co^IIions in the binuclear cluster exists in 10.Proton conduction experiments show that the conductivity of 10 and 11 are 2.659×10^-6 S·cm^-1 and 2.915×10^-6 S·cm^-1 at 70?and100%RH,respectively,which can be used as potential proton-conducting materials.