| In this paper,by choice and design of common ligands ethylenediamine,bi-pyridine,bis(triazole),bis(thiazole),bis(pyrazole),pyrazine carboxylic acids and other organic ligands,23 POM-based compounds have been synthesized by using hydrothermal and conventional method respectively.These compounds were characterized by X-ray single crystal diffraction,IR,element analysis methods.Through choosing and designing ligands,as well as selection of appropriate metal ions,we aimed to explore the synthetic rules of constructing POM-based compounds.We also explored the electrochemical and photocatalytic properties of these new compounds,as well as the fluorescence sensing properties of mercury ions.1.Two new isopolytungstate compounds,namely[Cu4(2,2'-bipy)4(H2O)2(W6O22)]4H2O(1)(Cu(en)2Na8(H2O)28(H2W12O42)]4H2O(2)(2,2'-bipy=2,2'-bipyridine,en=1,2-ethylenediamine),were synthesized under hydrothermal condition and in aqueous solution respectively,and characterized by single-crystal X-ray diffraction,elemental analyses and FT-IR spectra.In compound 1,there is a rare hexatungstate anion[W6O22]8-,which is firstly captured by copper(?)complexes under hydrothermal condition by using sodium tungstate.The[W6O22]8-cluster is covered by two[Cu(2,2'-bipy)]2+and two[Cu(H2O)(2,2'-bipy)]2+clusters to form a tetra-supporting anion.In compound 2,the paradodecatungstate anion[H2W12O42]10-was captured by[Cu(en)2]2+clusters in aqueous solution.The[H2W12O42]10-anions are linked by[Na3(H2O)10]3+and[Na2(H2O)8]2+clusters to construct an inorganic layer.The[Cu(en)2]2+clusters connect these inorganic layers to build a 3D framework of 2.We studied the electrochemical and photocatalytic properties of these compounds.1 showed good catalytic activity for photocatalytic degradation of RhB and 2 showed goog catalytic activity for photocatalytic degradation of MB.2.Through using flexible ethanediamine(en),bis(triazole)ligands and pyrazine carboxylic acids,a series of Anderson POM-based compounds were synthesized and structurally characterized.In isostructural compounds 3 and 4,the 2D grid-like layers and ID metal-organic chains arrange alternately through hydrogen bonding interactions.Compound 5 owns a 2D grid-like layer with Anderson anions linked by mono-and bi-nuclear Cu? clusters alternately.Compound 6 shows a ID cycle-connecting-cycle metal-organic chain with anions hanging on one side.In compound 7,the Cr2-anions are connected by[Cu3(btp)2]6+subunits to form a 2D layer.The Crl-anions link adjacent layers to build a 3D framework.In 8,the anions link ladder-like Cu-btp chains to construct a 3D framework,with K ions embedding in the channels.In addition,we are trying to explore whether Anderson/bis(triazole)base compounds can be obtained at room temperature using conventional methods.Therefore,we further introduce 1,3-bis(1,2,4-triazol-1-yl)propane into the CrMo6/Cd? system.Fortunately,we obtain a discrete Anderson structure 9.In the following work,we replaced small en molecules with triazoles and 2-pyrazine carboxylic acids,and successfully prepared four Anderson compounds 10,12-14 by conventional synthesis.In addition,we selected the flexible ligand 1,1'-bis(3,5-dimethyl-lh-pyrazole)methane(H2bdpm)to modify Anderson polyanions under hydrothermal conditions,and also successfully prepared a basket of polyacid compound 11.All the above Anderson compounds are based on Al/CrMo6 polyanions.We tried to introduce TeMo6 polyamons into the metal organic system,and successfully obtained a basket-like compound 15 under hydrothermal conditions.Therefore,we speculate that Anderson based compounds can be easily synthesized by conventional or hydrothermal methods as long as the conditions are right,such as selecting the right ligand.This attempt can promote the target synthesis of Anderson structural compounds.[{Cu?3(en)6}{Al(OH)6Mo6O18}2]24H2O(3)[{Cu?3(en)6}{Cr(OH)6Mo6O18}2]24H2O(4)[{Cu?3(en)4(?2-OH)2}{Al(OH)6Mo6O19}](5)[{Cu?(bte)2(H2O)}{HCr(OH)6Mo6O18}]5H2O(6)[{Cu?3(btp)2(H2O)4}{Cr(OH)6Mo6O18}2]6H2O(7)[{Cul2(btp)}{Cr(OH)6MO6O18}{K(H2O)2}](8)[Cd3(btp)2(H2O)14]H3[Cr(OH)6Mo6O18]3·16H2O(9){[Zn?5(trz)6(H2O)12][AlMo6(OH)6O18]2}·(HAlMo6(OH)6O18)23H2O(10){Cu?2(H2bdpm)2[HCr(OH)6Mo6O18]}(11)[{Cu?2(2-pyc)2}{HCr(OH)6Mo6O18}]·17H2O(12)[{Zn?2(2-pyc)2(H2O)2}{HCr(OH)6Mo6O18}]·18H2O(13){[Co?(2-pyc)(H2o)2]2[HCr(OH)6Mo6o18]}·15H2O(14){[Cu?3(tybm)3(H2o)4][TeMo6O24]}2·(H6TeMo6O24)·16H2O(15)3.By using two kinds of flexible bis(triazole)ligands 1,3-bis(1,2,4-triazol-1-yl)propane(btp)and 1,6-bis(1,2,4-triazol-1-yl)hexane(btx),four compounds based on octamolybdate and Keggin anions respectively were obtained under hydrothermal conditions.These compounds were structurally characterized by single crystal X-ray diffraction analyses,elemental analyses and IR spectra.In compound 16,there Is a metal-organic layer containing square tetra-nuclear cycles.Two layers cover[Mo8O26]4-anions to form a hamburger-like layer.Adjacent hamburger-like layers penetrate each other to build a 3D framework.Compound 17 owns a rhomboid tetra-nuclear cycle to surround a Mol-containing anion.These cycles are linked by btx ligands to construct a 2D layer.Adjacent layers are connected by Mos-containing anions and a 3D structure Is formed.Compound 18 shows bi-nuclear cycles,which are further linked by anions and Ag2 atoms to construct a 2D layer.In compound 19,the metal-organic chains are connected by Keggin anions to form a 2D structure.We also study the photocatalytic and electrochemical behavior of compounds 16-19.[Cu(btp)2(H2O)(?-Mo8O26)1/2](16)[Cu2(btx)4(?-Mo8O26)](17)[Ag3(btp)2(PW12O40)](18)[Cd(btx)3(SiW12O40)]·H2btx(19)4.Through using a S-containing ligand 2,2'-dimethyl-4,4'-bithiazole(dbt),a series of Wells-Dawson and Keggin based compounds were synthesized under hydrothermal conditions and structurally characterized.In compound 20 there are three dissociated subunits:Wells-Dawson anion,{Zn(dbt)3}2+and {Zn(dbt)2(H2O)}2+clusters.In compound 21,the mono-supporting Wells-Dawson anions exhibit abundant hydrogen bonding interactions with discrete {Cd(dbt)3}2+and {Cd(dbt)2(H2O)}2+clusters,constructing a supramolecular layer.Compound 22 owns a bi-nuclear Cd cluster{Cd2(dbt)4Cl}4+ with a Cl as a bridging atom.The Keggin anions link these bi-nuclear Cd clusters alternately to build a ID chain.In compound 23,a pair of {Cd(dbt)2}2+subunits connect adjacent two Keggin anions and a ID chain is formed.In these four compounds,only the N donors coordinate with Zn or Cd atoms,but the S atoms are uncoordinated.They show good fluorescence sensing performance to Hg2+.Furthermore,we also studied the electrochemical and photocatalytic properties of the title compounds.These compounds also can act as electrochemical sensors for the detection of nitrite.{Zn(dbt)3}{Zn(dbt)2(H2O)}2{HPZW?W?17O62}·4H2O(20){Cd(dbt)2(H2O)(HPZW?W?17O62)}{Cd(dbt)3}{Cd(dbt)2(H2O)}·13H2O(21){Cd2(dbt)4Cl}{PW12O40}(22){Cd2(dbt)4} {SiW12O40}(23)... |
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