Study On The Structure And Properties Of Metal-Organic Framework Materials Based On Nitrogen And Oxygen Organic Ligands

In this paper,some complexes of rare earth elements and transition metal elements with O-coordination and N-coordination ligands are assembled,and their photocatalytic and fluorescent properties are studied.Based on the principle of crystal engineering,their diverse structures are explored.The statistical results show that the complexes with o-and n-coordination functional groups are more coordinated.In this paper,five novel complexes are synthesized by using a series of oxygen-containing and nitrogen-containing organic ligands and a series of rare earth and transition metal ions under certain conditions.The crystal phase,structure and composition of these materials are analyzed in detail Photocatalytic degradation,sensitive detection,selective adsorption and separation of metal ions and nitroaromatic compounds were studied.The main results are as follows:(1)Based on the ligand of 5-(bis(3-benzylbenzoic acid)amino)benzene-1,3-dicarboxylic acid(H₄L),two new complexes[La(HL)(H₂O)]_n·3H₂O(1),[Er(HL)·3/2(H₂O)]_n·3/2H₂O(2)were synthesized by hydrothermal method.Complex 1 was a two-dimensional layered structure and complex2 was a three-dimensional network structure.In this chapter,the degradation of antibiotics by complexes 1-2 under visible light irradiation was studied.Among them,complexes 1 had good photocatalytic degradation effect on tetracycline(TC),and the rate constants of tetracycline photodegradation were 0.01128 min^-1and 0.00892 min^-1,respectively.According to the experimental results of active species capture,a possible photocatalytic degradation mechanism was proposed.(2)Two multifunctional luminescent complexes,[Cu(Hbcb)(PYTPY)]_n(3),[Cd(Hbcb)(PYTPY)]_n·2H₂O(4)with transition metal Cu²⁺and Cd²⁺as nodes were synthesized by hydrothermal method with 3,5-bis((5'-carboxybenzyl)oxy)benzoic acid(H₃bcb)and 4'-(4-pyridyl)-2,2':6',2'-terpyridine(PYTPY)ligands.Based on the good fluorescence characteristics of complexes 3-4,the fluorescence detection of metal ions and nitro compounds is studied in this chapter.Complexes 3-4 show the most obvious quenching phenomenon for Fe³⁺and nitrobenzene,and the fluorescence detection has strong anti-interference,which can be used for the detection of complex components.(3)Based on the ligand of 2-(2-carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline(2-HNCP)and 2-nitroterephthalic acid(NO₂-bdc)with Mn²⁺,the complex[Mn(2-NCP)(NO₂-bdc)]_n·0.5H₂O(5)was constructed.The complex 5 has a two-dimensional layered structure.In this chapter,the degradation of dyes by complex 5under visible light irradiation was studied.The results showed that complex 5 had good photocatalytic degradation effect on congo red(CR),methyl violet(MV)and methyl blue(MB),and the reaction rate constants were 0.01520 min^-1,0.00682 min^-1and0.00516 min^-1,respectively.According to the experimental results of active species capture,the possible mechanism of photocatalytic degradation was proposed.The paper has 74 figures and 10 tables and has cited 102 references.