Flexible Nitrogen-containing Heterocyclic Ligand Design And Synthesis And Characterization,

The construction of metal-organic frameworks (MOFs) based on organic ligand-metal coordinative bonding is of great interest, mostly motivated by their intriguing structural features and enormous range of application in magnetism, catalysis, adsorbent and molecular recognition. MOFs can be designed and constructed to generate cavities or channels of various sizes and shapes through the control of architecture and functionalization of organic linkers.As the organic ligand, nitrogen heterocyclic compound hold unique structure and coordinated property which can be formed the different 1D(one-dimension), 2D(two-dimension) or 3D (three-dimension) network structure polymers with many geometries by the reaction of nitrogen heterocyclic ligands with metal ions. Such kind of MOFs with the quality of complexes and composite polymers usually has unique unique optical, electricity, magnetic, catalytic, molecular recognition, adsorption, host-guest chemistry and biological activity according the published results. Therefor, it can be expected widely application prospects in aspect of novel materials, molecular recognition and self-organization.Imidazolyl group can be assembled into supermolecular of topology structure with metallic ions. Most of compounds have holes, cavities or pipes which have potential applications in the area of separation and purification, microreactor and ion exchange. The ligands containing imidazolyl group not only have abundant coordinated ability, but also can easily form hydrogen bond. Therefor, it is important to study their coordinated properties for synthesizing supermolecular compounds with hydrogen bond. Benzotriazole and its derivatives have structural characteristics and coordinated fashions. It can become one of excellent choices in constructing novel functional metal polymers.Base on the above investigate backgtound, two imidazole ligands and four bis-benzenetrizole ligands were designed and synthesized. Coordinated polymers by the reaction of these synthesized ligands with different metal salts also were tried. As a result, two metal-organic supermolecular ftamework were formed by self-organization and characterized by X-ray single crystal diffraction. All synthesized ligands and MOFs are reported first time and characterized by modern spectroscopy technology.This thesis consists of four parts:The first part of thesis review the research background which including two parts. The first part emphasized the synthesis and application of imidazole-containing aryl cores and their complexes. The coordinated polymers formed by self-organizing these ligands with different transition metal ions generally contain large pores and possess high-selectively catalytic and adsorption activity. Another part is given on the research process of ligands containing benzotriazole and their complexes. The synthesis and application of bis-benzotriazole ligands containing flexible alkyl bridge and their coordination compounds were emphasized. Bis-benzotriazole ligands containing aryl-core are seldom reported.In the second part, we synthesized two new ligands containing imidazole using materials such as 3,5-dihydroxytoluene, phloroglucinol. The products were confirmed by melt point, IR, ¹H NMR and element analysis.The third part of this thesis presented the preparation of four new bis-benzotriazole ligands by the reaction of benzotriazole with dibromide product of hydroquinone, resorcinol, naphthalene-1,5-diol, 3,5-dihydroxytoluene. All the products were characterized by melt point, IR, ¹H NMR and element analysis. It provided a premise to study structure-property relationship by comparing imidazole ligands to bis-benzotriazole ligands we have synthesized.In the forth part, two pore metal-organic supermolecular framework by 1,4-bis (imidazol-1-ylethoxy)-benzene and 1,3,5-tri(imidazol-1-ylethoxy)-benzene reacted with Cd(NO₃)₂·4H₂O were obtained. The structure of complex formed by the ligand 1,4-bis(imidazol-1-ylethoxy)-benzene show a centrosymmetric trinuclear structure. Cadmium atoms have six-coordinated fashion; two cadmium atoms have different environments in the unit. The complex formed by the ligand of 1,3,5-tri-(imidazol-l-ylethoxy)-benzene with Cd(NO₃)₂·4H₂O also shows six-coordinated fashion with slightly distortion octahedral. Each ligand is coordinated by three cadmiums; each cadmium atom is coordinated by six N atoms from six different ligands.