| In this paper,under hydrothermal conditions,pyrazole and thiazole derivativesareusedasorganicligands,suchas?3–thiophen–2yl–5–trifluoromethyl–2,3–dihydyo–1–H–pyzazole?ttdp?,1,1'–bis?3,5–dimethyl–1H–pyrazol–4–yl?methane?H2bdpm?,4–propyl–4,5–dihydro–1H–pyrazole?pdp?,2,2'–dimethyl–4,4'–bithiazole?dm4bt??.By changing the pH?temperature and type of POMs of the system,nineteen compounds based on Keggin,Wells–Dawson and isopolymolybdate polyoxometalate?POM?were obtained.Their structures were characterized by single crystal X–ray diffraction.Furthermore,we also have studied the electrochemical,electrocatalytic,photocatalytic,and fluorescent properties of these new POMs–based compounds.1.Under the same conditions of temperature and time,we have obtained two different structures 1 and 2,through the use of two pyrazole derivatives,1,1'–bis?3,5–dimethyl–1H–pyrazol–4–yl?methane?H2bdpm?,4–propyl–4,5–dihydro–1H–pyrazole?pdp?.Using the H2bdpm ligand,a Zn complex and five POMs–based compounds were obtained by tuning pH.[?Cu2?H2bdpm?2?[H2P2W18O62]0.5]·2H2O?1?[?Cu3?pdp?6Cl2?(H5PMo11CuO39)2]·12H2O?2?[Ag4?H2bdpm?4(SiW12O40)]·4H2O?3?[Ag3?H2bdpm?3(PMo12O40)]?4?[Cu?H2bdpm?2?H2O?2(HPMo12O40)]?5?[Zn?H2bdpm?2(?–Mo8O26)0.5]·3H2O?6?[?ZnO?2?H2O?2?H2bdpm?]?7?[(?–Mo8O26)?H2bdpm?2]·2H4bdpm·4H2O?8?In compound 1,the bidentate H2bdpm ligands link CuI centers to form a 1D wave–like metal–organic chain.Adjacent chains are parallel with each other,with Wells–Dawson anions occupying the gaps.In compound 2,six pdp ligands are coordinated to three CuIII centers to form a trinuclear cluster.Two Cl–anions are also coordinated to the copper centers.The mono–Cu?II?–substituted Keggin anions connect the trinuclear clusters to construct a 2D grid–like structure.In compound 3,the infinite wave–like metal–organic chains are linked by POM anions to form a 3D framework.In the compound 4,the H2bdpm ligands are linked by Ag+ions to construct a chain with[PMo12O40]3–anions suspending up and down this chain by hydrogen bonding interactions.In compound 5,there is a mono–supporting[PMo12O40]3–anion with one[Cu?H2bdpm?2?H2O?2]2+subunit.By tuning pH of[Mo7O24]6–/Zn2+/H2bdpm system with three values,three distinct structures 6-8 were constructed.In compound 6,two Zn ions and two H2bdpm form a bi–nuclear[Zn2?H2bdpm?2]4+cycle.Adjacent cycles connect each other vertically to build a cycle–connecting–cycle chain.In compound 7,the cycle–like[?ZnO?4?H2O?4]subunits are linked by a pair of H2bdpm alternately to form a 1D chain.Compound 8 contains only a[?–Mo8O26]4–anion functionalized by two H2bdpm through Mo–N bonds.2.Using a new organic ligand 3–thiophen–2yl–5–trifluoromethyl–2,3–dihydyo–1–H–pyzazole?ttdp?,two new Keggin–based supramolecular compounds were synthesized under hydrothermal conditions and their electrochemical and photocatalytic properties were also studied.{[Ag?ttdp?2]3[PMo12O40]}·3H2O?9?{[Ag?ttdp?2]3[HSiMo12O40]}·3H2O?10?Crystal structure analysis reveals that compounds 9 and 10 are isostructural,containing one discrete Keggin anion and three metal–organic subunits[Ag?ttdp?2]+.The Keggin anions and[Ag?ttdp?2]+subunits arrange alternately through hydrogen bonding interactions,forming a supramolecular 1D chain.Adjacent 1D chains link each other through hydrogen bonding interactions to further construct a supramolecular 2D layer.3.By using a dm4bt?2,2'–dimethyl–4,4'–bithiazole?ligand,eight Keggin–based and an isopolymolybdate compounds were obtained.At the same temperature,by using different metal ions,we obtained different structures compounds 11 and 12,13 and 14.We obtained compounds 15 and 16,17 and 18by one–pot method,and using an appropriate pH range seems to be rational to obtain two or more types of crystals in one pot.When we used the same synthetic conditions with that of compounds 17 and 18 except tuning pH,we obtained the distinct compound 19.{[Ag?dm4bt?2][Ag2?dm4bt?3]}2(PW12O40)(H2PW2VW10VIO40)?11?[CuI?dm4bt?2][CuII?dm4bt?2(PW12O40)]?12?[CuI?dm4bt?2]4(SiW12O40)?13?{[Zn?dm4bt?2]2(SiW12O40)}?14?[Zn?dm4bt?2?H2O?]2(HPMo2VMo10VIO40)·2H2O?15?[Zn?dm4bt?2?Mo2O7?]?16?[Cd?dm4bt?3][Cd?dm4bt?2?H2O?(PMo12O40)]2·2H2O?17?[Cd?dm4bt?3](PMo12O40)·?Hdm4bt??18?[Cd?dm4bt?2?H2O?2]2(HPMo2VMo10VIO40)·2H2O?19?In compound 11,there are three isolated subunits:Keggin anions,bi–nuclear[Ag2?dm4bt?3]2+and mono–nuclear[Ag?dm4bt?2]+clusters.The bi–nuclear[Ag2?dm4bt?3]2+cluster owns Ag–Ag bond.In compound 12,there exists a mono–supporting anion{[CuII?dm4bt?2](PW12O40)}-and an isolated[Cu?dm4bt?2]+cluster.By changing the TM ions,we have got two different structures:a supramolecular 13 and a bi–supporting anion in 14.In compound 15,the[Zn?dm4bt?2?H2O?]2+subunit links adjacent PMo12 anions via S…O interactions to form a 1D supramolecular chain.In compound 16,some PMo12 ions have transformed to[Mo2O7]n2n-chains.The[Zn?dm4bt?2]2+clusters buckle up and down the chain.In compound 17,the[Cd?dm4bt?2?H2O?]2+cluster connects the PMo122 through Cd–O bond to form a mono–supporting structure.These adjacent mono–supporting anions build a 1D supramolecular chain via hydrogen bonding interactions?O2W…O35=2.747??.In the compound 18,the adjacent PMo12anions connect[Cd?dm4bt?3]2+subunits via S…O interactions?S4…O38=3.266?,S4…O39=3.217??to construct a 1D supramolecular POM–based chain and the discrete dm4bt ligands suspend above the POM by S…O interactions?S7…O3=2.965??.In the compound 19,a[Cd?dm4bt?2?H2O?2]2+cluster connects adjacent anions to build a 1D supramolecular chain?S1…O3=3.223?,O17…O2W=1.992??. |
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