| As a most popular research topic in chemistry,materials and so on,the investigation of metal-organic coordination polymer has changed to the diversification of functionality from the structural diversity.Chemists have devoted to develop practical coordination polymers and a series of polymers working as adsorbing materials,conductive materials,catalytic materials,medical materials and luminescent materials have been synthesized,and lanthanide-based metal-organic frameworks（Ln-MOFs）formed by lanthanide-metal centers and organic linkers have attracted attention and potential application value as a new type of fluorescent probe.Therefore,4-（（3-（pyrazin-2-yl）-1H-pyrazol-1-yl）methyl）benzoic acid（Hpypymba）,4-（（3-（pyridin-2-yl）-1H-pyrazol-1-yl）methyl）benzoic acid（Hpyznpy）,with both rigidity（such as phenyl,pyrazine,etc.）and flexibility（-CH2-）were selected as the organic ligands,and six novel coordination polymers have been synthesesd by hydrothemal method,together with rare earth metal ion Tb3+,Nd3+,Eu3+,Sm3+and transation metal ion Pb2+.The structures of the complexes were analyzed by X-ray diffraction.The coordination polymers were characterized by elemental analysis,thermogravimetric analysis and fluorescence analysis.Finally,the fluorescence properties and the catalytic activity of the compounds were studied.Six new compounds:Pb（pypymba）2（1）,{[Tb2（pyznpy）6·4H2O]·2H2O}n（2）,{Eu2（pypymba）6·4H2O]·2H2O}n（3）,{Nd（pypymba）3·2H2O]·2H2O}n（4）,{Nd（pyznpy）3·2H2O]·2H2O}n（5）,{Sm（pypymba）3·3H2O]·H2O}n（6）,were hydrothermally synthesized.X-ray diffraction analysis results show that:the compounds 1-6 belong to the triclinic crystal system with P-1 space group;the compound 1 is six-coordinated,and the coordination arrangement around the Pb（II）is a distorted octahedron;The smallest repeating unit of the compound 2-4 is a diatomic asymmetric structure,with two independent metal ions（Me1 and Me2）,all of which are all eight-coordinated,the coordination geometry of Me1 can be viewed as a distorted dodecahedron and Me2 shows the distorted square antiprism geometry coordinated,the compounds 2-4 feature a 1D six petal-like motifs,which is further stabilized by hydrogen bonds andπ···πinteractions to form a 3D;The coordination geometry of Me1 can be viewed as a distorted dodecahedron,with eight-coordinated of the compounds 5 and 6,the compounds 5 and 6 feature a 1D the“cross”motifs,which is further stabilized by hydrogen to form the 3D structure.In addition,the detection and recognition of small molecular organic solvents and metal ion activity of compound 2,compound 4 and compound 6,and the catalytic activity of compound 4 were studied in this paper.The results showed that:（1）The compound 2,compound 4 and compound 6 could be an efficient multifunctional fluorescence probes for sensitivity sensing of nitrobenzene with the detection limit at 1×10-5 M,1×10-5 M and1.5×10-5 M,respectively;（2）The compound 2 could be an efficient multifunctional fluorescence probe for sensitivity sensing of Fe3+with the detection limit at 1×10-5 M;（3）The compound 4 could be an efficient multifunctional fluorescence probe for sensitivity sensing of Tb3+with the detection limit at 5×10-7 M;（4）The as-prepared Ag@Eu-MOF 4was synthesized by liquid phase infiltration method,which has remarkable catalytic performance to reduce 4-NP,with a reducyion rate constantκas large as 2.07×10-2 s-1.As a result,this study enriches the selection of fluorescence probes and catalytic,which provides a new approach to develop fluorescence sensor and catalytic. |
