Multicomponent Self-assembly And Properties Study Based On Citrullus Ring And Keggin-type Heteropolyacids

Heteropolyacids,also called polyoxometalates(POMs),it has been a long history of development.Cucurbit[n]urils(Q[n]s)are a kind of supramolecular compound with a novel cage-like body and a hydrophobic cavity.Carbonyl oxygen atom at the port is negatively charged,and the waist has a strong positive charge.Therefore,using the positive charge of the outer wall of Q[n]s to interact with POMs anion,which has become one of the hot spots of supramolecular chemistry research in renset years.In this paper,we have designed a serious of Q[n]-POMs supramolecular self-assemblies,Q[n]s:(OH)₁₀Q[5],Me₁₀Q[5],Q[6],POMs:H₄PMo₁₂O₄₀(PMA),H₄SiW₁₂O₄₀(STA)and H₅Eu(SiW₁₁)₂(LnSTA).The research work is as follows:1.Synthesized series of POMs LnSTA(Ln:La,Ce,Pr,Nd,Sm,Eu,Gd,Tb).The characterizations of these POMs were confirmed by infrared spectra,X-ray powder diffraction and so on.2.Synthesized series of Q[n]s-POMs supramolecular self-assemblies,Five kinds of compound crystals were obtained under different conditions marked as A{(OH)₁₀Q[5]·STA},B{(OH)₁₀Q[5]·STA·2K},C{Gd₂(H₂O)Cl₂·(HO)₁₀Q[5]}·STA·12H₂O,D{Cd Cl₂K·(HO)₁₀Q[5]}₂·STA·2H₃O,E{Ba₂(H₂O)Cl₂·(HO)₁₀Q[5]}·PMA·12H₂O and four kinds of multi-component self-assemblers Q[n]s-POMs(F:Me₁₀Q[5]STA,G:Me₁₀Q[5]EuSTA),Q[6]-POMs(H:Q[6]EuSTA,I:Q[6]STA).The characterizations of these self-assemblies were analyzed by X-ray single crystal diffraction,FT-IR,PXRD,TG-DTA and ITC analysis methods,Which Q[n]-EuSTA is belong to the innovation point of.3.The functional properties of these self-assemblies were investigated.1).It was found that the synthesized self-assembler has certain photocatalytic degradation of organic dye MB in aqueous solution,and the total decolorization rate D_twas higher than 93%;2).It has a certain catalytic effect on esterification reaction;3).It has photochromic properties under normal temperature and pressure under natural light conditions.