Synthesis And Properties Of High Dimensional Metal-Organic Frameworks Based On Pillararene-based Polycarboxylate Ligands

Metal-Organic Frameworks?MOFs?is a kind of crystalline porous materials with highly regular and infinitely extended network structure,which is self-assembled from polydentate organic ligands containing oxygen and nitrogen and inorganic metal centers?metal ions or metal clusters?.Metal-Organic Frame materials have crystalline properties,diversified structures and permanent porous properties.So it has a wide range of applications.For example,it can be used as electrode materials,catalytic reactions,molecular recognition,fluorescent probes and other fields.MOFs have been extensively studied in the past decades,and now MOFs materials are moving from laboratory to industrialization.This paper is divided into three main parts.The first part studies the construction of two high-dimensional MOFs based on pillararene skeleton polycarboxyl ligands and the design and synthesis of fluorescent composite material MOF@TPE.Firstly,complexes 1 with two-dimensional planar structure were constructed by solvothermal method using polycarboxyl modified pillar[5]arene ligand?H4L¹?and bipyridine ligand with transition metal Zn²⁺.Since the pillar[5]arene unit in complex 1 is an electron-rich cavity,it can be an ideal host for electron-deficient guest molecules.We have selected tetraphenylethylene?TPE?molecules with aggregate-induced luminescence properties modified with a cyano group at the end,The host-guest interaction between complex 1 and tetraphenylethylene molecule was verified by 1H NMR,Then the fluorescence characteristics of the new fluorescent composite MOF@TPE were studied.Finally,under the action of basic tetrazine bipyridine ligands,H₄L¹ and Zn²⁺constructed a complex 2 with three-dimensional network structure.In the second part of this thesis,the specific fluorescence response of the new fluorescent composite MOF@TPE to Fe³⁺,2-nitroaniline and L-cysteine was studied.The composite material MOF@TPE was ground and dispersed in an ethanol solution of various test substances to prepare a uniform stable suspension.The fluorescence spectra showed that the composite MOF@TPE exhibited high specific fluorescence quenching response to Fe³⁺,2-nitroaniline and L-cysteine.In the third part of this paper,MOFs with C3 symmetry hexacarboxylic acid ligand?H6L³?modified by polyamide bond were studied.Under solvothermal conditions,complexes 3 and 4 with three-dimensional network structure were constructed by H₆L³ and Co²⁺/Ni²⁺.Single crystal analysis revealed that the two complexes were heteromorphic.Since the complexes have excellent solvent stability,large porosity and functional amide functional groups,their adsorption properties for iodine molecules have been studied.