Syntheses And Characterizations Of Coordination Polymers Based On Nitrogen-containing Aromatic Multicarboxylate Ligand

Metal-organic coordination polymers have aroused widespread interests in the fields of chemistry and materials owing to the potential applications in catalysis,gas storage and separation,fluorescent identification,drug delivery,magnetism and other aspects.Under solvothermal conditions,fourteen novel complexes have been successfully synthesized based on 6-(3,5-dicarboxylphenyl)nicotinic acid(H3DCPN)and several N-donor co-ligands [4,4'-bis(imidazolyl)biphenyl(4,4?-bibp)? 1,4-bis(benzimidazo-1-ly)benzene(1,4-bbib)?1,2-bis(imidazol-1-ylmethyl)benzene(1,2-bimb)?1,4-bis(1-imidazoly)benzene(1,4-bib)?1,3-bis(imidazol-1-ylmethyl)benzene(1,3-bimb)?4,4'-bipyridine(4,4?-bpy)],in the presence of various transition metal ions and rare earth metal ions.The formulas of 1-14 are as follows:{[Co(HDCPN)(4,4?-bibp)]·1.5H2O}n(1){[Co1.5(DCPN)(4,4?-bibp)1.5(H2O)]·H2O}n(2){[Co(HDCPN)(1,4-bbib)(H2O)]·2H2O}n(3)[Co(HDCPN)(1,4-bbib)]n(4){[Co8(DCPN)4(1,2-bimb)4(OH)4]·(CH3CN)0.5(H2O)2}n(5){[Co2(DCPN)(1,3-bimb)(OH)]·H2O}n(6){[Ni3(DCPN)2(1,4-bbib)4(H2O)4]·(CH3CH2OH)2(H2O)3}n(7)[Mn3(DCPN)2(4,4?-bibp)3(H2O)4]n(8)[Cd(HDCPN)(1,4-bib)0.5(H2O)2]n(9){[Cd3(DCPN)2(4,4?-bibp)2(H2O)]·1.5H2O}n(10)[Cd3(DCPN)2(4,4?-bibp)2(H2O)2]n(11){[Co(HDCPN)(4,4?-bpy)0.5(H2O)]·H2O}n(12){[Tb2(DCPN)2(H2O)4]·(DMA)(H2O)6}n(13)[Sm(DCPN)(DMSO)2]n(14)The single-crystal X-ray diffraction analysis shows that complex 1 is a sql/Shubnikov two-dimensional network structure;2 is a 3-nodal(3,4,6)-connected 3D structure;3 is a sql 2D network structure,and the adjacent layers interpenetrate with each other to generate 2D + 2D ? 2D networks,then they pack into a 3D supramolecular architecture via hydrogen bonds;4 is a sql 2D bilayer network,and the complex packs into a 3D supramolecular structure via H-bonds;5 exhibits a 2-nodal(3,6)-connected structure with a kgd topology;6 shows a 2-nodal(3,10)-connected 3D structure with the Schl?fli symbol of(418·624·83)(43)2;7 is a 3-nodal(3,4,5)-connected 2D net;8 displays a(3,10)-connected 3D trinuclear structure and belongs to 3,10T3(MOF.ttd);9 is a one-dimensional chain,which is further linked into a 3D network through hydrogen bonds;10 can be simplified as a 2-nodal(3,10)-connected 3D structure;the architecture of complex 11 is constructed by the interpenetration of the 3D binuclear structure formed by DCPN3-ligands and Cd(II)ions,and the 2D structure formed by 4,4?-bibp molecules and Cd(II)ions;12 is a(3,4)-connected 2D bilayer network,and then packs into a 2D + 2D ? 3D parallel polycatenation network via hydrogen bonds;13 exhibits a(3,6)-connected 3D structure with the Schl?fli symbol of(42·6)2(44·62·87·102);the 3D binuclear architecture of 14 is formed by DCPN3-ligands and neighbouring binuclear secondary building units.13 and 14 are isomorphic.In addition,these complexes were characterized by powder X-ray diffraction(PXRD),elemental analysis(EA),infrared spectrum detection(IR)and thermogravimetric analysis(TG).At the same time,the magnetic susceptibility measurements for complexes 1,3,4,5,6,8 and 12 were collected,showing that 1,3,4,5,6 and 12 display the weak antiferromagnetic behavior while 8 shows weak ferromagnetic interactions.Furthermore,the field-dependent magnetization and alternating current susceptibility measurements were conducted of 8.Besides,the fluorescent properties of 9,10,11,13 and 14 were measured.The result shows that 10 exhibits efficient fluorescence quenching behavior upon the addition of p-nitrophenol(NP),and 11 shows better fluorescence quenching behavior in 4-nitrobenzenamine(NA).Complexes 13 and 14 dispersed in DMSO display the strongest luminescent intensity,which exhibit the weakest emission in acetone.Both 13 and 14 show efficient fluorescence quenching behavior of p-nitrophenol(NP)and 4-nitrobenzenamine(NA),however,the fluorescent recognition ability of 14 is relatively strong.