Structures And Fluorescent Probe Properties Of Metal Complexes Constructed By Tetra-acid Ligands

Metal coordination polymers?MCPs?are a new class of polymers,which are constructed from metal ions and organic ligands.They are emerging at the interface between molecular coordination chemistry and material science.Besides,fine-tuning and uniform pore structure of MCPs make them a promising microporous material,which have attracted great attentions.Nowadays,various MCPs systems have been reported for the purpose of gas storage,gas separation,heterogeneous catalysis,and small-molecule sensing.Among them,sensing remains largely unexplored until recently.Several groups have reported their discoveries on MCPs sensors aimed at the convenient detection of explosives,chemical vapors,and O₂.Particularly,luminescent MCPs have potential applications as sensors.In this thesis,metal-organic coordination polymers with novel structures and good properties were synthesized by using and designing organic ligands with specific functions.The applications in fluorescence detection are discussed in detail.Contents completed in the paper are as follows:Firstly,the three dimensional?3D?coordination polymer based on 1,2,4,5-benzenetetracarboxylic acid?H₄bta?ligand:two luminescent coordination polymers[Zn₂?bta??ppda?]_n?1?and[Co₂?bta??ppda??H₂O?₂]_n?2?were synthesized by hydrothermal method.In 1,adjacent Zn?II?ions were bridged to a two-dimensional?2D?sheet by bta^4-ligands,and the 2D sheet was further connected by ppda ligands to form a 3D structure.In 2,bta^4-ligand coordinates to the Co?1?and Co?2?form the adjacent inorganic chains,which was further formed the honeycomb channels.The ppda ligand coordinated to two Co?2?atoms from two adjacent inorganic chains and through the honeycomb channels to enhance the stability of the 3D framework.Meanwhile,the fluorescence detection ability of both 1 and 2 for nitro-aromatic compounds?NACs?and metal ions Fe³⁺were discussed.The results showed that both 1 and 2 have high sensitivity and low detection limit.Therefore,1 and 2 could regard as fluorescence probes to detect NACs and metal ions Fe³⁺with high sensitivity.In addition,the magnetic properties of 2 was preliminarily tested.Secondly,the two dimensional?2D?coordination polymer based on azobenzene-3,3',5,5'-tetracarboxylic acid azotetraacid?H₄L?ligand:two lanthanides luminescent coordination polymers{[Gd?H₂O?₂?HL?]?H₂O}_n?3?and{[La?H₂O?₄?HL?]?H₂O}_n?4?were synthesized by solvothermal conditions with H₄L ligand.Both 3 and 4 are demonstrated highly sensitivity and selective for 2,4,6-trinitrophenol?TNP?.Besides,4shows a favourable regeneration on Fe³⁺ions.Meanwhile,the mechanism of the detection of Fe³⁺by 4 was also further discussed.