| Coordination polymers?CPs?are a kind of crystal material with periodic and highly structured infinite network topology formed by the self-assembly of metal ions or metal clusters with organic ligands,which has a 3D reticular ordered pore structure also known as metal organic frameworks?MOFs?.As a new family of porous materials with intriguing framework topology,abundant porosity,and tunable optical properties,CPs have shown potential applications in a good number of fields.Over the past two decades,luminescent CPs have attracted growing attention,especially for developing luminescent sensor materials,by virtue of their excellent selectivity and high sensitivity.As well known,the self-assembly process of coordination polymers is affected by a lot of factors,including organic ligands,metal centers,solvent,temperature and pH and so on.Choosing organic ligands with structural characteristics are important in the construction of CPs.So far,carboxylic ligands have been used to construct CPs with many intriguing framework,in which polydentate carboxylate ligands containing donor atom are excellent structural builders and have been widely employed.On the one hand,donor sites accessible can act as functional sites for efficient interactions with guests.On the other hand,the variety of coordination modes available to polydentate carboxylate ligands allows access to a wide variety of structures.In this work,using polydentate carboxylate containing donor atom,3-?3,5-dicarboxylphenyl?-5-?3-carboxylphenyl?-1-H-1,2,4-triazole?H3L?,3,3?,5,5?-azobenzene-tetracarboxylic acid?H4abtc?and 1,3,5-tri?4-carboxyphenoxy?benzene?H3tcpb?as organic ligands,Zn?II?and Cd?II?as metal centers,we have prepared seven coordination polymers under solvothermal conditions.Their fluorescence and sensing properties were also studied.The main research results include the following aspects:1.By using H3L ligand and Zn?II?/Cd?II?,two CPs{[Zn3?L?2?4,4'-bipy??DMF?2]·2H2O}n?1?and{[Cd3?L?2?4,4'-bipy??H2O?2]·2DMF}n?2??DMF=N,N?-dimethylformamide?were solvothermally prepared.1 and 2 are isostructural and exhibit 3D structure.Notably,1 exhibits good luminescent sensing for nitro-containing compounds and Fe3+ions,which can be used in the development of fluorescent probe.In addition,the emission of 1 can be tuned from yellow to white and to blue by encapsulating different mole ratios of Eu3+and Tb3+ions and changing the excitation wavelength.Moreover,when excited at 340 nm,white light emission of1 is obtained with the Commission International de I'Eclairage?CIE?coordinates of?0.331,0.337?,which are very close to the values for ideal white-light?0.333,0.333?.This indicates 1 is a potential white light material.2.By using H4abtc ligand and Zn?II?/Cd?II?,three CPs were solvothermally prepared,{[Zn2?abtc??bpa??H2O?]·5H2O}n?3?,{[Cd3?abtc?2]·2H3O}n?4?,and[Cd3?H2abtc?3?bpp???2-OH2?2?H2O?3]n?5?.3 and 4 are 3D structure,while 5 exhibits a2D layered network.CPs 3-5 display promising photoluminescence properties in the solid state at room temperature.In addition,3 exhibits good sensitivity for Fe3+ions and nitrobenzene.3.By using H3tcpb ligand and Zn?II?/Cd?II?,two CPs were prepared,{[Zn2?tcpb???2-OH?]·5H2O·DMF}n?6?and{[Cd2?tcpb???2-OH?]·5H2O·DMF}n?7?.6and 7 are isostructural 2D layered network.From the viewpoint of structural topology,the whole structure of 6 and 7 can be reduced to a 2D?3,3?-connected network with the extend point symbol of{63}.CPs 6 and 7 display promising photoluminescence properties in the solid state at room temperature.In addition,compound 6 exhibits good sensitivity for acetone and N,N?-dimethylacetamide?DMA?. |
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