Design,Construction And Performance Of Multifunctional Metal-Organic Frameworks

Metal-organic frameworks（MOFs）are a kind of open crystalline frameworks with permanent porosity and highly regular,which is self-assembled from inorganic metal nodes or clusters polydentate organic ligands containing oxygen and nitrogen.Rapid advances in the field of reticulated chemistry including MOFs stem from their various intriguing structures,tailorability and functional diversity,gradually realizing industrialization and functionalization,rendering them useful for a plethora of applications including gas storage and separation,fluorescent probes,drug delivery and heterogeneous catalysis.This thesis was divided into three main parts.The first part studied the construction of MOFs based on the triphenylamine skeleton ligands.Firstly,the triphenylamine skeleton tetracarboxyl ligand（H₄L¹）was synthesized by tris（4-bromophenyl）amine and p-methoxycarbonylphenylboronic acid through multi-steps Suzuki coupling reactions which was verified by single crystal X-ray crystallography、¹H NMR、¹³C NMR、IR and ESI-MS.Then the complex Cd（L¹）（NO₂）₂（H₂O）·guest（1）was constructed through solvothermal method by ligand H₄L¹ and transition metal ion Cd²⁺which was charactered by crystal X-ray crystallography、TGA、IR and PXRD.The second part studied the construction and applications of MOFs based on H₄L²（tetrakis[（6-carboxynaphthoxy）methyl]methane）.Thecomplex Cu₂（L²）（DMF）（H₂O）·guest（2）and Mn_1.5（L²）（DMF）（H₂O）·guest（3）were synthesized through solvothermal method.Due to the larger neutral channels of complex 2 whose porosity could reach up to 62.7%,resulting in that it could not only adsorb quercetin whose size was similar to channels,but also convert it into the complex with Cu which was verified by UV-vis、IR、ESI-MS and TEM-EDS Mapping.To our surprise,complex 2 could efficiently extract quercetin from natural onion juice and directly convert it in complex with Cu which was also charactered.The complex 3 was a two-dimensional planar structure of trinuclear manganese clusters,which could not only stay stable in clean solvent water,but also exhibit fluorescence quenching response to Fe³⁺with moderate selectivity and sensitivity.It was a novel kind of fluorescent material with ppm level detection limit.The main mechanism could attribute to the energy competition and resonance between Fe³⁺and complex 3.The third part of the thesis studied the construction of exceptionally stable MOF based on the pillar[5]arene skeleton tetracarboxyl ligand（H₄L³）.The complex Co₂（HL³）（OH）（H₂O）₃×guest（4）with tetranuclear metal cluster and pillar[5]arene cavity inside was synthesized through solvothermal method by H₄L³ and metal ion Co²⁺.The complex 4 was found not only had good thermal stability,but also could remain crystallinity in air,water,even in the acidic water（pH=3）for three months through characterizations.Due to the introduction of electron-rich pillar[5]arene,both the H₄L³ and complex 4 exhibited host-guest interactions with three amino acids of different electrical properties（Gly/Glu/Arg）.