Synthesis,Structures And Properties Of MOFs Based On Ligand/Solvent Regulation Strategy

In this thesis,starting from simple aromatic aldehydes and ketones,a series of chalcone and 2,4,6-triarylpyridine organic luminescent materials are prepared through Aldol reaction and Krohnke pyridine synthesis reaction.They can also be used as effective organic ligands to build metal-organic frameworks(MOFs)and coordination polymers(CPs)with diverse structures and functions.Three positionally isomerized pyridyl derivatives containing imidazo[1,2-a]pyridine group(IP)are referred to as IP-2-Py,IP-3-Py,IP-4-Py,and three chalcone ligands are denoted as L1,HL2,HL3,while three rigid pyridinecarboxylic acid ligands are denoted as HL4,HL5,H2L6.A total of 13 MOFs/CPs materials were synthesized,which are marked as[ZnCl2(L1)2](1),[Zn(L2)2]n(2),[Zn(L3)2(H2O)]n(3),[Cd(-3)2(H20)]n(4),[Mn(-3)2(H20)4](5),{[Zn(L4)2]�2DMF}n(6 or USTC-5),{[Co(L5)2]-0.6DMA�1.5H2O}n(7 or USTC-2),{[Zn(L5)2]�0.6DMA�1.5H2O}n(8 or USTC-3),{[Co2(L6)2(H2O)]�0.6DMF�8H2O}n(9 or USTC-4),[Cd(HL6)2]n(10),[Zn(HL6)2]n(11),[Co(HL6)2]n(12),{[Ni(L6)(H2O)2]�H2O}n(13).Their structures have been characterized by single crystal X-ray diffraction(SCD),powder X-ray diffraction(PXRD),infrared spectroscopy(IR),thermogravimetric analysis(TGA)and elemental analysis(EA).Meanwhile,the properties of materials including luminescence,magnetism,fluorescence sensing,stimulus response,and gas adsorption have also been investigated.The results show that the three pyridine derivatives have acid-base stimulated phosphorescent reversible color properties,and the Zn(?),Cd(?),and Mn(?)complexes have excellent photoluminescence properties,while Co(?),Ni(?)complexes reveal antiferromagnetic behaviors.In addition,compounds 9-13,which are all constructed from the H2L6 ligand,have different structural dimensions from 1D to 3D.The various structure/dimensionality of them essentially originates from the types of organic solvents,which can cause complete or partial deprotonation of the H2L6 ligand.The three MOFs materials USTC-2/3 and USTC-4 show different adsorption capacities for N2 and CO2,which can be attributed to different interpenetration conditions.USTC-5 is a stable and novel three-dimensional metal organic supramolecular framework material.It displays interesting reversible luminescent color switching in the response to acid-base vapor stimuli,and the significant fluorescence quenching recognition of Fe3+,Cr2O72-,CrO42-,MnO4-and nitrobenzene.The sensing behaviors of acid-base vapor and ions/molecules can be attributed to the reversible change of supramolecular structure and the similar energy transfer mechanism,respectively.Through the research in this paper,a series of CO2/N2 selective adsorption materials and fluorescent sensing materials have been synthesized,which have potential application value in the fields of gas separation,environmental monitoring,biosensing and molecular devices.Furthermore,the research results in this paper further explain the structure-activity relationship between the structure and properties of materials,and promote the research of chemistry and materials science.