Coordination Polymers Based On 5-sulfoisophthalic Acid Sodium Salt:Synthesis,Crystal Structures And Properties

Coordination polymers are a kind of organic-inorganic hybrid compounds with periodic structures formed by metal ions or metal clusters bridged by organic ligands.Due to their abundant structural types and diverse functional properties,coordination polymers have important potential applications in the fields of light,electricity,magnetism,catalysis and adsorption,and are one of the current hot directions in synthetic chemistry and materials science research.In this thesis,two crystalline coordination polymers with entangled structures were successfully prepared as photocatalysts and proton-conducting materials,respectively,by diffusion method using 5-sulfoisophthalic acid sodium salt and 4,4'-bipyridine as bridging ligands and inexpensive transition metal salts with both versatility and strong coordination ability as metal centers:[Co3(SIPA)2(4,4'-bpy)4(H2O)6]·(H2O)4(1)[Cu6O3(HSIPA)3(4,4'-bpy)6(H2O)3]·(H2O)7(2)We choose 5-sulfoisophthalic acid sodium salt and anhydrous copper acetate as raw materials,a crystalline coordination polymer was successfully prepared by the evaporation solvent method and its proton conductivity was measured:[Na2(H2O)3Cu2(H2O)6(SIPA)2]·H2O(3)We choose 5-sulfoisophthalate sodium salt and 4,4'-bipyridine as ligands,using lanthanide metal salts with photoluminescence and strong coordination ability to provide metal centers,four isomeric crystalline coordination polymers were successfully prepared by diffusion method:[Pr(SIPA)(H2O)5]2·(4,4'-bpy)3·(H2O)(4)[Nd(SIPA)(H2O)5]2·(4,4'-bpy)3·(H2O)(5)[Sm(SIPA)(H2O)5]2·(4,4'-bpy)3·(H2O)(6)[Dy(SIPA)(H2O)5]2·(4,4'-bpy)3·(H2O)(7)The first three crystalline coordination polymers were basically characterized by elemental analysis,XRD,PXRD,TGA,IR and UV-Vis analysis methods.Compound 1 is a twofold-interpenetrating 3-D coordination polymer with qzd topology.The photocatalytic system was constructed using compound 1 in combination with[Ru(bpy)3]Cl2.The system was highly efficient in catalysis under visible light irradiation,regardless of the CO2 concentration.It is worth mentioning that the yields of CO and H2 reduced under pure CO2 conditions could reach 989.7 ?mol g-1 h-1 and 823.4 ?mol g-1 h-1,respectively.Mechanism studies have shown that photoelectron transfer occured between[Ru(bpy)3]Cl2 and compound 1,which effectively increased the output of C02 reduction.Compound 2 is a 3-D self-penetrating coordination polymer with a brand new(4·5·6)(4·52)(4·53·62·7·83)(4·55·6·73)(53·63)five-node topology.The proton conductivity was measured under different temperature and humidity conditions.It could reach 6.95×10-4 S cm-1 at 98%RH,85?,indicating that the proton conductivity of compound 2 was moderately resistant to high temperature.This work filled the scarcity of 3-D nonporous coordination polymers in the field of proton conduction research.The results of fluorescence measurements showed that the photoluminescence properties of compound 1 was derived from the characteristic emission of the ligand.Compound 2 was derived from the combined effect of the characteristic emission of the ligand and the electron transfer from the ligand to the metal.Compound 3 is based on two different sodium clusters and copper as the metal centers,and rely on 5-sulfoisophthalic acid sodium salt to connect to form a 3-D structure.Due to its own deliquescence,the proton conductivity of compound 3 was only roughly measured under constant temperature and humidity conditions with a short duration,reaching a proton conductivity of 1.75×10-3 S cm-1 at 98%RH,65?.Compound 4-7 are 3-D isostructural coordination polymers with different lanthanide metals as the metal centers.They may have good proton conductivity with the large number of hydrogen bonds in their structures.