| In this dissertation,we design and synthesize a double bond-containing pyridine ligand(E,E-2,5-dihexyloxy-1,4-bis-[2-pyridin-viny1]-benzene)(L).This ligand incorporating different multicarboxylates and transition metal ions has been adopted to successfully construct ten new coordination polymers under solvothermal conditions.Their syntheses,crystal structures and properties were investigated and discussed.The main content includes the following two parts:1.Solvothermal reactions of(E,E-2,5-dihexyloxy-1,4-bis-[2-pyridin-vinyl]-benzene)(L)with 4,4'-sulfonyldibenzoic acid(H2sdb),4,4'-oxybisbenzoic acid(H2oba),1,4-cyclohexanedicarboxylic acid(H2chd),fumaric acid(H2fma)and 4,4'-biphenyldicarboxylic acid(H2bpdc)in the presence of different transition metal ions yielded ten new complexes:{ZnL(chd)}n(1),{[Zn(L)0.5(oba)]·DMF·H2O}n(2),{[Zn(L)0.5(sdb)]-H2O}n(3),{[Zn(L)(bpdc)]·2DMF}n(4),{[Cd(L)0.5(sdb)]-DMF}n(5),{Cd(L)(sdb)}n(6),{[Cd(L)(fma)]·0.5H2O}n(7),{[Co(L)0.5(sdb)]·DMF}n(8),{Co(L)(sdb)}n(9),{[Cu(L)0.5(sdb)]·DMF}n(10).Complexes 3,5,8 and 10 were similar isomorphic with different metal ions(Zn2+,Cd2+,Co2+and Cu2+).Their secondary building units are paddle wheel structures(Cd paddle wheel structure seems not to be reported so far),they all display 3D framworks with {44.62}-sq1 topologies.Complex 1 belongs to triclinic crystal system with space group P?,it displays a 3D framwork with {66}-dia topology.Complex 2 belongs to monoclinic crystal system with space group P21/c,it displays a 3D framwork with {44.610.8}-mab topology.Complex 4 belongs to monoclinic crystal system with space group P2/c,it displays a 3D framwork with {66}-dia topology.Complex 6 belongs to triclinic crystal system with space group Pl-,it displays a 2D framwork with {44.62}-sql topology.Complex 7 belongs to monoclinic crystal system with space group P2/c,it displays a 2D framwork with {44.62}-sq1 topology.Complex 9 belongs to triclinic crystal system with space group Pl,it displays a 2D framwork with {44.62}-sql topology.2.We chose five complexes and studied their applications on luminescence sensing of small molecules and dye adsorption.Luminescence sensing of different metal cations and inorganic anions was performed on MOFs 1-3.The results show that Fe3+has the highest quenching efficiency for three MOFs up to 99%.And Cr2O72-exhibits the most significant quenching efficiency up to 90%.These two ions show extremely high quenching efficiency on MOFs 1-3.Luminescence sensing of different metal cations and organic molecules was performed on MOFs 5 and 7.The results show that Fe3+has the highest quenching efficiency up to 95%.The quenching efficiency can reached about 40%for salicylaldehyde.Compared to 6%of other solvents,it shows high selectivity.We studied the possible mechanism of luminescence quenching.It can be explained in terms of the competitive absorption of excitation wavelength energy between small molecules and these complexes.In addition,we also studied the adsorption capacity of MOF 5 towards dye molecules under different pH value(pH=2.8 and 7).The adsorption capacity of MOF 5 towards other four dyes(methyl orange,acid orange 10,methylene blue,rhodamine b)except congo red is low in pH=7.Surprisingly,the adsorption capacity towards anionic dyes is significantly improved in pH=2.8.Removal percent of MO and AO can reach to 95%.While it does not happens to cationic dyes.We think the adsorbent surface characteristics are different in these two conditions.In pH=2.8,electrostatic interaction between the anionic dyes and MOFs with positively charged surface can be the important reason responsible for selectively adsorbing anionic dyes. |
PDF Full Text Request