Study On The Regulatory Factors Of Coordination Polymer Structure

Metal-organic frameworks have potential applications in selective adsorption,catalysis and gas storage due to their diverse structures,high specific surface area and easy functionalization.In this paper,exploring the carboxyl end group coordination of the ligand to form of the structure and properties of coordination polymer is the main purpose,research a series of azo type of ligand and three key bridging ligands,and with the two types of ligands as the research object,study the form of coordination polymer with transition metal ions conditions,the structure of synthetic coordination polymer have been characterized,focus on the synthesis of ligands optimization,the influence of different anionic coordination polymer structures are discussed.The main research results are as follows:(1)The azo ligands H2L1?H2L4 were synthesized from m-aminobenzoic acid,phenol,p-hydroxyphenylacetic acid,and methyl bromoacetate,bromopropane,allyl bromide,and 3-bromopropyne.The coordination polymers {Zn(L2)·(H2O)2}n(1),{Cd(HL4)2(H2O)2·0.5(H2O)}n(2)and {Mn(L4)2(H2O)2}n(3)were synthesized.The origin of single chirality of coordination polymer 1 is discussed.Its chirality only exists in orange single crystal.The powder with rapid crystallization does not have chirality,the chirality of its sigle crystal is related to the crystallization process.Coordination polymers 2 and 3 are cadmium and manganese based coordination polymers prepared from 3-(4-carboxymethoxyphenyl azo)benzoic acid(H2L4).Compound 3 is difficult to be obtained directly by conventional methods,but the complex polymer 2 and manganese acetate were prepared by hydrothermal structural transformation method.Through this synthesis strategy,not only complex 3 with the two-dimensional network structure can be prepared,but also the coordination polymer formed by the azo ligand with good magnetic properties be obtained.(2)Ligand 2,6-bis(3'-pyridine acetylenyl)-4-methylaniline(L5)and ligand 2,6-bis(3'-pyridine)-4-methylaniline(L6)was synthesized.In the mixed solvent(methylene chloride-methanol),L5 react with CoCl2 and Co(SCN)2 through self-assembly reaction at room temperature.The {CoL5Cl2}n(4)with one dimensional structure and {Co(L5)2(SCN)2}n(5)with two dimensional structure were synthesized.The difference of structure between 4 and 5 is based on the different anion.Coordination polymers with different structures were obtained from anions with different coordination abilities.By using the Cu(OAc)2,the complexes{Cu2L5(OAc)4}2(6)with cyclic structure and {Cu2L6(OAc)4·2(CH2Cl2)·(CH3CN)}n(7)with one dimensional structure were obtained by self-assembly reaction of L5 and L6,which proved that the ligand size could affect the structure of coordination polymers.The complexes and coordination polymers were characterized by X-ray single crystal diffraction,infrared,fluorescence analysis and elemental analysis.