Synthesis Of Nitrogen-containing Heterocyclic Ligands, Organic Carboxylic Acid Ligands And Metals (Zn(II), Cd(II), Pb(II), Ni(II), Co(II), Cu(II)) Organic Framework Materials, Structural And Magnetic And Fluorescent Properties Studies

Metal Organic Frameworks(MOFs)are a type of porous crystalline material with periodic structure formed by self-assembly of metal ions or clusters and organic ligands.Because MOFs have attractive physical and chemical properties such as high surface area,high porosity,abundant active sites and flexible chemical structure,they are currently widely used in catalysis,chemical sensing,gas adsorption and separation,supercapacitors and other fields.Due to the special structure and wide application prospects,the directional design and synthesis of MOFs have attracted much attention.By exploring the relationship between the structure and performance of MOFs,it can provide a rich theoretical basis for its practical application.In the present thesis,we have chosen m-bix,p-bix,btx,bbi(m-bix=1,3-bis((1H-imidazolyl)-methyl)benzene;p-bix=1,4-bis((1H-Imidazolyl)-methyl)benzene;btx=1,4-bis(1,2,4-triazole-1-methyl)benzene;bbi=1,4-bis(imidazol-1-yl)-butyl Alkyl)and other nitrogen-containing heterocyclic ligands as the main ligand,2,5-thiophene dicarboxylic acid,2-(4-chlorobenzoyl)-benzoic acid,5-nitroisophthalic acid,1,4-naphthalene Polycarboxyl organic ligands such as dicarboxylic acid and3,3-dimethylglutaric acid as auxiliary ligands that coordinated assembly with transition metal ions of Zn(?),Cd(?),Ni(?),Co(?),Cu(?)and p-block metal ion of Pb(?),and 12 crystals with novel structures were obtained by hydrothermal/solvothermal method synthesis.The structure and composition of the crystal were characterized by techniques of X-ray single crystal diffraction,elemental analysis,infrared spectroscopy and thermogravimetric analysis.The crystal structure was in-depth analyzed and discussed by using crystal structure analysis software such as Diamond,Olex and Topos,exploring the bonding mode of coordination units and the interaction between coordination units of the complex.The magnetic properties and fluorescence properties of the complexes were studied using variable temperature magnetic susceptibility and excitation/emission spectra.The specific research results are as follows:(1)A series of transition metal and p-block metal complexes with novel structures of{[Zn(tdc)(m-bix)]H₂O)}_n(1),{Cd(cbba)₂(m-bix)₂}_n(2),{Pb(cbba)₂(m-bix)}_n(3)and{Ni(nip)(p-bix)(H₂O)₂}_n(4)were synthesized by using m-bix and p-bix as main ligands,2,5-thiophene dicarboxylic acid,2-(4-chlorobenzoyl)benzoic acid,and 5-nitroisophthalic acid as auxiliary ligands.There are abundant intermolecular hydrogen bonds in complexes 1-4.Complex 1 is a three-dimensional supramolecular structure formed by a two-dimensional layer through hydrogen bond interaction.Complexes 2 and 3 are both dinuclear metal complexes.The three-dimensional supramolecular structure is formed by hydrogen bonding.The difference is that the binuclear structure of complex 3 is formed by hydrogen bonding.Complex4 is directly connected by ligands to form a three-dimensional supramolecular structure.The strong fluorescence emission of complexes 1-3 indicates that they can be used as potential photoluminescent materials.(2)A series of the transition metal complexes with novel structures of{[Co₅(btx)₂(NDC)₄(?₃-OH)₂(H₂O)₂])_n(5),{[Zn₂(btx)₂(NDC)₂]}_n(6),{[Cd(tdc)₈(bbi)₈(H₂O)₈]·4DMF)}_n(7)and{Cu(bbi)(dgc)}_n(8)were synthesized by using btx and bbi as the main ligands,1,4-naphthalenedicarboxylic acid,2,5-thiophene dicarboxylic acid,and 3,3-dimethylglutaric acid as auxiliary ligands.Complex 5 is a 10-connected three-dimensional network structure formed by the pentanuclear metal cluster[Co₅(?₃-OH)₂(COO)₈]and ligand btx and 1,4-naphthalenedicarboxylic acid.Complex6 is a three-dimensional network structure connected by hydrogen bonding.Complex7 is a 4-connected triple-interleaved three-dimensional structure.Complex 8 is directly connected by ligands to form a three-dimensional network structure.In the magnetic study of complexes,complex 5 exhibits weak antiferromagnetism,and complex 8 exhibits ferromagnetic force.Fluorescence tests of complexes 6 and 7 have been carried out.The strong fluorescence emission of the two complexes indicates that they can be used as potential photoluminescent materials.(3)An inorganic salt and three organic ligand single crystals of{[C₅H₁₂Co NO₆}_n(9),{[(btx)(H₂PDC)]}_n(10),{[C₅H₁₁ClO₃}_n(11)and{[(H₂nip)(H₂O)]}_n(12)were synthesized by using 2,5-thiophene dicarboxylic acid,1,4-phenylene diacetic acid,methyl 4-(4-chloro-benzoyl)benzoate,5-nitroisophthalic acid,nitrogen-containing heterocyclic ligand btx,and their structures were characterized.Among them,there are a large number of hydrogen bonds,and the three-dimensional supramolecular structure is formed by intermolecular or intramolecular hydrogen bonds.