| The POMs based on Keggin,as a member of six types typical structures, ncludes a number of bridge and terminal oxygen atoms to form lots of interesting structure compounds with excellent applications through connecting with plentiful transition metal ions.Seven novel inorganic-organic hybrid compounds with uncommon Keggin polyoxometalate templates have been hydrothermally synthesized by using rigid or flexible ligands to modify it.And seven compounds are studied by elemental analysis,TG,UV,IR,DFT and single crystal X-ray diffractions.At the same time that the seven compounds have been studied,containing electrochemical properties,electrocatalytic properties,fluorescent properties and photocatalytic properties.The molecular formula of seven compounds:?H2biz?2?Hbiz?[PMo12O40].2H2O?1?[Ag2?Hpz??pz?(PMo12O40)]?2H2O?2?[?H2bib??Hbib?(PMo12O40)]?3?[{Cu?phen?2}2{Si W12O40}]?4??Hbib?4[Ag2(SiW12O40)]2?5?[{Ag4?pz?7{SiW12O40}]?6?[{Ag2?pz?2}{Ag2?pz??H2O?2}{SiW12O40}]?7?(biz=benzimidazole;pz=pyrazine;bib=?1,4-bis?imidazol-1-ylmethyl?benzene;1,10-phen=1,10-Phenanthroline?Crystal structure analysis displays that the compounds of 17 consist of[XM12O40]n-?X=Si,P;M=Mo;W?cluster anions.Compounds 13 are POMs complexs based on{PMo12}.Meanwhile,a series of compounds have been successfully synthesized under higher temperature to highest temperature by selecting from rigid ligands to flexible ligand.In compound 1,{PMo12}polyanions are surrounded benzimidazole ligands to form 1D chain via?-?interactions,extending 2D layer and 3D structure.Compound of 2 consists of coordinational complex[Ag2?pz?2]n2n+and[PMo12O40]n3n+anions connecting together to form 3D structure,possessing two-type pore structures.Interesting,the structure likes“magic cube”.Compound 3 is maked{PMo12}polyanions and flexible ligand of larger space steric hindrance,forming 1D chain via supramolecular interactions.The 1D chains extend to 2D layer with“wave”that formed 3D structure via supramolecular interactions,too.Compounds 47 are POMs complexs based on{SiW12}.Meanwhile,a series of inorganic-organic hybrid compounds have been designed and assembled from zero dimension to high dimension via adjusting the reaction conditions.Compound 4 are modified by Cu-O bonds to shape zero dimension.Interesting,the 1D chains contain two kinds of units that the first unit is opposite from the second unit,forming A-B-A-B chain via supramolecular interactions.Two kind chains shape“dumbbell”2D layer via supramolecular interactions,too.The“dumbbell”2D layers are formed 3D structure via?-?interactions.In compound 5,two crystallographically independent Ag ions?Ag1 and Ag2?,are rare eight-coordinate to connect eight O atoms of{Si W12}cluster anions.Every[SiW12O40]4-cluster and two Ag ions form A-B-A-B chain via Ag-O bonds,extending2D layers and 3D structures via hydrogen bonding and supramolecular interactions.Compounds 6-7 are both 3D MOF structures that{Ag-pz}units connect{Si W12}clusters,but compound 6 is connected with Ag-O bonds to shape A-B-A-B chain,surrounding huge 3D MOF structure each other.And compound 7 exists two type units of metal-organic coordination mode,The first one is Ag ions link N atoms of pyrazine ligands to form?2-N connection mode,and another one is Ag ions link C atoms of pyrazine to form?4-C coordination mode.Observingly,there are four complete Ag-C bonds are impacted the result of sp2 C-H activation of pyrazine ligand.Ag ions and pyrazine ligand surround to link{SiW12}clusters to form 1D chain each other.{Ag-pz}units as linker to connect two{SiW12}clusters to shape a completely parallel structure and possess MOF structure with two type infinite{Ag-pz}channel.Eight Ag ions link{SiW12}to form huge 2D structure based on connection mode of Ag-C,which 2D layers connect adjactent{Ag-pz}units to form 3D net via Ag-O bonds.Electrochemical properties of compounds 1-7 all contain three pairs redox peaks by cyclic voltammetry curve,the results belong to reduction of Mo/W atoms.Meanwhile,compounds 1-7 indicate fine electrocatalytic activity for hydrogen peroxide and excellent fluorescent properties choose to luminescent materials.Additionally,the photocatalytic properties of Rhodamine-B for compounds 1-7 have been researched at the room temperature condition.The results display that compounds 1-7 reveal good conversion rate of the degradition with RhB that they achieve all above 90%under ultraviolet light.The results indicate compounds 1-7 of photocatalytic properties are excellent. |
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