| Metal coordination polymers have wide variety of skeleton structures and exhibit superior properties in optical,catalytic,gas adsorption and magnetic fields.Therefore,in recent years,the design and synthesis of novel metal coordination polymers have attracted wide attention of scholars.In this paper,5-?benzimidazol-2-yl?isophthalic acid,pyrazine-2,3-dicarboxylic acid,3-?3,5-two carboxyl group benzene?,3-?3,5-dicarboxylphenyl?-5-?3-carboxylphenyl?-1H-1,2,4-triazole as ligands have been reacted with metal salt,24 complexes were obtained,and the fluorescence and magnetic properties of some complexes were investigated.The main work of this paper is as follows:1.Studies on syntheses,structures and properties of rare earth/transition coordination polymers based on 5-?benzimidazol-2-yl?isophthalic acidThirteen complexes were synthesized under hydrothermal conditions by using5-?benzimidazol-2-yl?isophthalic acid as ligand,reacting with rare earth/transition metal ions.In complexes 1-12[Ln?HL1?2?NO3?]n?Ln=La?1?,Ce?2?,Pr?3?,Nd?4?,Sm?5?Eu?6?,Gd?7?,Tb?8?,Dy?9?,Er?10?,Yb?11?,Y?12??,L12-ligand adopts three-bridged coordination mode to connect Ln3+ion to form one-dimensional coordination chain.The uncoordinated nitrogen atoms of L12-ligand in the structure are protonated,which can form hydrogen bonds with the uncoordinated carboxyl oxygen atoms on the adjacent coordination chains.Each chain is linked with four adjacent chains by hydrogen bonds to form three-dimensional supramolecular network structure.In complex 13[Zn3?L1?3]n,the ligand adopts four-bridged coordination mode to link the Zn2+ions to form three-dimensional coordination framework.The studies of fluorescence in aqueous solutions of complexes 3 and 13 indicated that NB and Fe3+ions showed significant fluorescence quenching on both complexes.The fluorescence quenching of Fe3+ion was confirmed by detect fluorescence of complexes containing mixed ions.The quenching constants of NB are 9.33×104 and 96 L/mol,respectively.The quenching constants of Fe3+ions are 8.18×104 and 2.19×105 L/mol,respectively.Moreover,the fluorescence quenching of complexes 6 and 8 in DMF and H2O shows that the complexes have higher sensitivity to NB in DMF,and have higher sensitivity to Fe3+in H2O.The magnetic test of complexes 2-11 shows that the metal ions of complex 7 have ferromagnetic interactions in the 2-300 K,and the metal ions of complex 8 have ferromagnetic interactions in 18-2 K,the complexes 7-10 exhibit single-molecule magnets?SMM?behavior.2.Studies on syntheses,structures and properties of lanthanide coordination polymers based on pyrazine-2,3-dicarboxylic acidBy selecting pyrazine-2,3-dicarboxylic acid as ligand,four homogeneous 3d-4f heteronuclear metal complexes 14-17{[Ln2Zn?L2?4?H2O?6]?2H2O}n?Ln=Eu?14?,Gd?15?,Tb?16?,Tm?17??andthreehomogeneouslanthanidecomplexes18-20{[Ln2?L2?3?H2O?]?2H2O}n?Ln=Eu?18?,Gd?19?,Tb?20??were obtained by reacting with transition metal ions and rare earth nitrates under hydrothermal conditions.The studies of fluorescence in aqueous solutions of complexes 16 and 20 indicated that NB showed significant fluorescence quenching on both complexes.The quenching constants of NB are 1.10×102 and 2.82×102 L/mol,respectively.In addition,the quenching of Fe3+,Co2+and Cu2+on complex 16 and 20 is similar.The magnetic test of complexes 14 and 16-18shows that the metal ions of complex 16 have ferromagnetic interactions in 8-2 K,the complexes 16 and 17 exhibit single-molecule magnets?SMM?behavior.3.Syntheses,structures and properties of coordination polymers based on 3-?3,5-dicarboxylphenyl?-5-?3-carboxylphenyl?-1H-1,2,4-triazoleFour metal complexes 21-24{[Ln?L3??H2O?2]?3H2O}n?Ln=Dy?21?,Ho?22?,Er?23?,Tm?24??were synthesized by using 3-?3,5-dicarboxylphenyl?-5-?3-carboxylphenyl?-1H-1,2,4-triazole as ligand under the hydrothermal condition.In the complex,Ln3+ion is eight coordinated,that coordinated with two O atoms of H2O molecules and six O atoms from five different ligands.The L33-ligand adopts five-bridged coordination mode to link Ln3+ions to form two-dimensional layer structure.The studies of fluorescence in aqueous solutions of complex 24 indicated that NB and Fe3+ions showed significant fluorescence quenching on the complex.The fluorescence quenching of Fe3+ion was confirmed by detect fluorescence of complexes containing mixed ions.The quenching constant of NB is 1.02×104 L/mol.The quenching constant of Fe3+ions is 9.26×104L/mol.The magnetic test of complexes 21-24 shows that the metal ions of complexes21-22 have ferromagnetic interactions in 20-2K,the complexes 21-23 exhibit single-molecule magnets?SMM?behavior.H2L1=5-?benzimidazol-2-yl?isophthalic acidH2L2=pyrazine-2,3-dicarboxylic acidH2L3=3-?3,5-dicarboxylphenyl?-5-?3-carboxylphenyl?-1H-1,2,4-triazole... |
PDF Full Text Request