| Metal-organic frameworks?MOFs?,as crystalline solid materials,are composed of metal ions and organic ligands.In this paper,a series of MOFswere obtained by solvent thermal synthesis based on functional tetracarboxylate ligands.Their structures were characterized bythe single crystal X-ray diffraction infrared spectra?IR?,powder X-ray diffraction spectra?PXRD?,elemental analyses and thermogravimetric analysis?TGA?.At the same time,according to the characteristics of the frameworks,their properties about degradation of organic pollutants,catalysis of organic reactions as heterogeneouscatalysts,andsingle-crystal-to-single-crystal?SC-SC?transformationhave been explored respectively.1.Two heterotrimetallicMOFs[?CH3?2NH2][Cd2Na?Fe-?L-1??2?H2O?2]·4DMF·4H2O?1?and ZnNa?Fe-?L-1???H2O?]·2DMF·2H2O?2?have been synthesizedvia the reaction of a novel tetracarboxyl-functionalized1,2-ethanediamino-N,N?-bis(3-tertiarybutyl-5-??3,5-carboxybenzyl?oxy?salicylidene?H6L-1?Schiff base ligand.In 1and 2,the internal[N2O2]pockets of L6-anions are embedded by Fe?III?ions,while the external carboxylate groups are ligated by Zn?II?/Cd?II?and Na?I?ions.Both frameworks display fascinating 3D frameworks.The photodegradation properties of 1and 2 to 4-chlorophenol?4-CP?and 2,4-dichlorophenol?2,4-DCP?under visible lighthave been systematically investigated.2.Three functionalcoordination polymers[?CH3?2NH2]2[Cd3?L-2?2?H2O?2]·6H2O?3?,[Ba4?L-2?2?H2O?8]·H2O?4?and[Zn?H2?L-2???H2O?2]·H2O?5?,?H4L-2=3,5-bis?3?,5?-dicarboxylphenyl?-1H-1,2,4-triazole?weresynthesizedby tetracarboxylate ligands with Lewis base sites under solvothermal conditions.3-5exhibit fascinating multi-dimensional framework structures.Knoevenagel condensation reactions were investigated by using 3-5as heterogeneous catalysts under solvent-free conditions.Among them,3 as a recyclable catalystshows highly efficient catalytic performance in respect to4 and 5,which may be attributed to the open Lewis base sitesand Lewis acid Cd?II?sites inthe open channel of 3.3.A water-stable cationic MOFwith large nanotubular channels?ca.1.4×1.4nm2?,{Cu2[CuCl?TTCA??H2O?2]}?NO3?4DMA?6H2O?1-Cl??H4TTCA=1,4,7,10-tetrazazcyclododecane-N,N?,N??,N???-tetra-methylene-cinnamic acid?,was synthesized.Remarkably,the resulting porous material exhibits rapid aqueous-phase removal of Cr2O72-via an anion-exchange manner.Meaningfully,the capture and separation of aqueous Cr2O72-are highly selective even in the presence of large excesses of other competing anions.More importantly,the crystal structure of 1-Cl after anion exchange{Cu2[Cu?TTCA??H2O?2]}?0.5Cr2O7?NO3?7.5H2O?1-Cr2O7?could be accurately determined by single crystal X-ray diffraction,further elaborating theSC-SC transformation.4.A MOF[Cu2?Cu-?L-3???H2O?3?NO3?2]?Xguest?1-Cu?with nanocubic cageby an azamacrocycle-based tetracarboxylate?H4L-3=1,4,8,11-tetrazacyclotetradecane-N,N?,N??,N???-tetra-methylene-benzoicacid?wassynthesized.Andan effectivecharge-assisted POM-template-directed approach was developed to build a new family of POMs-resided POMs@2-Cu materials,namely,{Cu2[Cu-?L-3??H2O?]?H2O?2}4?[PMo12O40]?5NO3?Xguest(2a-PMo12),{Cu2[Cu-?L-3??H2O?]?H2O?2}4?[PW12O40]?5NO3?Xguest(2b-PW12),{Cu2[Cu-?L-3??H2O?]?H2O?2}4?[SiMo12O40]?4NO3?Xguest(2c-SiMo12),{Cu2[Cu-?L-3??H2O?]?H2O?2}4?[SiW12O40]?4NO3?Xguest(2d-SiW12),{Cu2[Cu-?L-3??H2O?]?H2O?2}4?[GeMo12O40]?4NO3?Xguest(2e-GeMo12).Significantly,they feature open channels with high-POMs-dispersed active sites that can be accessed,enablingthem selective catalytic oxidation of mustard gas,2-chloroethyl ethyl sulfide?CEES?,at room temperature.Systematic investigation through varying POMs nested in POMs@2-Cu demonstrates that the degradation efficiencies for the toxic CEES are highly dependent on the POM types used.Such a modular synthetic strategy may be applicable to the rational design of otherhigh-POMs-dispersed porous MOF materials with potential applications.The heterogeneous catalyst 2a-PMo12 can be easily separated and reused with good catalytic activityfor catalytic oxidation of CEES. |
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