Study On Syntheses And Properties Of Metal-Organic Frameworks Based On D-(+)-Camphoric Acid And Nitrogen-rich Ligands

Due to the mild synthesis conditions and modular composition of MOFs,the pore structure,pore environment,functional sites and other properties of MOFs can be systematically adjusted by selecting appropriate building blocks.These unique advantages make MOFs act as a highly versatile and adjustable functional platform.In this study,by mixing the ligand synthesis strategy,isostructural compounds 1-6with different metal centers were successfully synthesized.By adjusting the nitrogen-rich ligands,compounds 7-9 were obtained.The structure and physic-chemical properties of these MOFs were characterized and tested.The functional properties of the compounds were investigated.The content are presented as follows:1.By employing mixed ligands synthesis strategy,using the nitrogen-containing ligand 3,6-bis?2-methylimidazolium?-pyridazine?b2mmp?and carboxylic acid ligand D-?+?-camphoric acid?CHA?to react with Co²⁺,Mn²⁺,Cu²⁺,Ni²⁺,Zn²⁺and Cd²⁺ion,the isostructural compounds 1-6 were synthesized.The structure analysas shows there are a large number of unsaturated coordination metal centers and nitrogen atoms within the pore of compounds 1-6.,which can be used as a Lewis acid and base sites,respectively.Thanks to their characteristicstructure they were applied to the carbon dioxide cyclic carbonate reaction.The results show that compounds 1-6possess a better catalytic performance,and compound 5 exhibits the best catalytic activity under the mild condition.2.Chiral ligands CHA and cadmium acetate to react with 4,6-bisimidazopyridine?bmm?,4,6-bis?4-methylimidazolyl?pyrimidine?b4mm?,and3,6-bis?4-methylimidazolium?pyridazine?b4mmp?,respectively,compounds 7-9 were prepared.Compounds 7 and 8 are isostructural 2D layers,and both are crystallized in the chiral space groups.Compoud 9 is three-dimensional homochiral structure with new topology net.Compounds 7-9 all exhibit photoluminescence properties,and the fluorescence sensing properties of compounds 7 and 8 were investigated.Compounds7 and 8 show better fluorescence sensing ability for acetone and Fe³⁺;however,they exhibit significant differences in fluorescence sensing the chiral organic small molecule?oxidized styrene?.Compound 8 exhibited a better enantioselective sensing ability than 7.