Syntheses, Structures And Characteristics Of Coordination Polymers With Flexible Bis-azole Ligand

In recent years, coordination polymers with flexible bis(triazole) and bis(imidazole)N-donor ligands have attracted much attention owing to the development of their application in fluorescence, catalysis and magnetism. Bis(4-(4H-1,2,4-triazol-4-yl)phenyl)-methane(btpm) has been selected as a bridging ligand owing to its N1, N2-bridging mode.It can make a short bridge between two close metal atoms, which contributes to the production of polynuclear complexes. Flexible bis(imidazole) N-donor ligand1,4-bis(2-methylimidazol-1-ylmethyl)benzene(bix) can adopt different conformations to construct coordination polymers with intriguing topologies and properties.Eleven novel polymers based on btpm ligand and bix ligand have been synthesized.{[Cd4(btpm)3(Hfum)(fum)3Cl(H2O)2]·9H2O}n(1), {[Cd2(btpm)(mbda)2(H2O)]·3H2O}n(2),{[Cd3(btpm)2(1,4-bdc)3]·6H2O}n(3), {[Cd2(btpm)(meip)2(H2O)]·1.25H2O}n(4),{[Cu4(OH)2(btpm)2(5-NO2bdc)3]·3H2O}n(5), {[Zn(btpm)(adc)]·3H2O}n(6),{[Zn(btpm)(1,4-bdc)](1,4-H2bdc)}n(7), [Co(bix)(ndc)]n(8), [Cu(bix)0.5(glu)]n(9),[Cd(bix)(mbda)]n(10), [Zn(bix)(adc)]n(11).Coordination polymers(1-5) are polynuclear owing to N1,N2-bridging mode of btpm.Polymers(1、3、4) respectively consist of the Cd4, the Cd3 and the Cd2 dimers cluster. In complex 5, an interesting tetranuclear copper(II) cluster have been observed. Polymer 6shows that 2D(4,4) waved network structure. Polymer 7 exhibits 2D(6,3) honeycomb network structure and 3D supramolecular structure by hydrogen bond interactions. Both of polymers(8、10) are unusual 4-connected self-catenated 3D network and bix using anticonformation. The structure of 9 is also very distinctive, carboxylic acid ligand H2 glu connect with Cu(II) formed a 2D grid, 2D grid connect to each other by bix display a novel three-dimensional system. We have found that complex 11 presents one-dimensional chain containing alternative two kinds of rings [Zn2(adc)2] and [Zn2(bix)2] by bix usinggauche-conformation.Coordination polymers with cadmium(II) and zinc(II) have showed excellent fluorescence, they can be used as potential luminescent material. Coordination polymers(5、8、9) have showed evident photocatalytic activity under UV light irradiation.