The Structure Regulating And Optics Properties Of Flexible Triazole Coordination Polymers

In recent years, more and more coordination polymers with various novelstructure have been synthesized. Meanwhile, its application in gas adsorption andseparation, ion exchange, chiral molecular recognition, catalysis, luminescence,magnetism and sensing have been studied extensively. However, there are manyfactors affecting the structure of coordination polymers. Geometry and coordinationproperties of ligands, coordination geometry of metal ion plays a decisive role on thewhole structure. Besides, there are some other factors reported in the literature suchas solvent, pH and reaction temperature, anions, organic or inorganic templatemolecule, the ratio of reactants have a significant impact on the structure of thecomplexes. Therefore, it is necessary for us to accumulate the experimental data,explore the synthesis law in order to provide an experimental basis for the synthesisof specific coordination polymer.In this paper, we select a flexible triazole derivative, namely,1,4-bis(1,2,4-triazole-1-methylene)-2,3,5,6-tetramethyl benzene (btmx) and conduct studies fromthe following two aspects:1. By introducing different carboxylate ligands or changing pH, wesynthesize eight coordination polymers of ZnII/CdII-btmx. Wherein complexes1and7contain the same organic ligand, while defferent central metal ions. Due to thelarger coordination number of CdII, the two carboxyls of H2phsa adopt uniformbidentate chelating mode resulting in a typical two-dimensional complex7with (4,4)lattice structure. In complex1, owing to less coordination number of ZnIIions, twocarboxyl groups of H2phsa using μ1-η1: η0bridging mode to form a complexthree-dimensional structures. Similar to complex7, complexes2and3have a typicaltwo-dimensional (4,4) lattice structure, this may due to the intrinsic steric hindranceof carboxylic acid ligands. If H2phsa, one reactant of complex7is replaced byflexible succinic acid, which has samller sterichindrance, a three-dimensionalframework8generates. Rigid1,3,5-benzenetricarboxylic acid, supports a3Dframework with large grid, these3D frameworks interpenetrate parallelly to form a more complicated complex4. The reaction condition of complex6is same tocomplex5except that2mL0.1M NaOH solution is added. Complex6is acomplicated structure containing brilliant CdII/COO-cluster.2. By changing the reaction conditions, we obtain four different complexes9-12with combination of btmx and Cu(NO3)23H2O and CuCl22H2O, respectively.Wherein complexes9and10was obtained both by reaction of CuCl22H2O andbtmx in water under the same temperature, except that some adipic acid was addedin the reactants of complex10. Reaction of CuCl22H2O and btmx in differentsolvents generate different products11and12.9,11,12exhibit different efficiency incatalytic degradation of methyl orange under visible light...