Design And Preparation Of Heteropoly-organic Hybrids With Ionic Liquid Structures And Their Catalytic Performances

According to the designability of ionic liquids structures, more than40kindsof Br nsted acidic heteropoly-organic hybrid materials with ionic liquid structures and16Br nsted-Lewis acidic heteropoly-organic hybrids containing metalcations (Al3+, Zn2+, Cs+, Sm3+, Ce3+, Zr4+) have been designed and synthesized. Theorganic cations N-methylimidazole, morpholine, pyrrolidine, glycine,triethylamine and heteropolyanions PW12O403-, PMo12O403-, SiW12O403-, PV3Mo9O406-have been empoled in the structures of hybrids. The hybrid catalysts were characterizedby means of1H-NMR, FT-IR, thermogravimetry, n-BuNH2potentiometric titration, andelemental analysis.The prepared heteropoly-organic hybrids catalysts have been used for thebenzylation reaction of anisole with benzyl alcohol. The effects of amount of catalyst,reaction temperature, reaction time and other factors on the reaction have been studied togive the optimum conditions. When the benzylation reaction was catalyzed byH2[MIMPS]PW12O40, under the optimum reaction conditions: t=2h, T=155℃, Molarratio=1:1，M(cat)=0.1mmol,99.7%benzyl alcohol have turn into the object productsmethoxy diphenyl methane, in which the selectivity for2-and4-isomers are46.6%and53.4%respectively. The H2[MIMPS]PW12O40catalyst can keep good catalyticperformance after3recycles.The prepared heteropoly-organic hybrids catalysts have been used for thebenzylation reaction of toluene with benzyl alcohol. The effects of temperature, time,the amount of catalyst and other factors on the reaction have been studied, and theoptimum conditions over Sm0.33[MIMPS]HPW12O40catalyst were obtained: t=2h,T=110℃, Molar ratio=4:1, M(cat)=0.1mmol. Under the above optimum conditions, the conversion of benzyl alcohol could reach up to96.7%, and the selective of2-and4-methyl diphenyl methane were20.8%and23.5%respectively. After5recyclesthecatalyst still exhibited higher catalytic activity.The intermolecular dehydration of benzyl alcohol has also been studied with theabove prepared heteropoly-organic hybrids catalysts. The effects of temperature, time, theamount of catalyst and other factors on the catalytic performance have been studied.Ce0.33[MIMPS]2PW12O40has been found to be the most suitable catalysts. Under theoptimum conditions: t=2h, T=160℃, M(cat)=0.075mmol, the conversion of benzylalcohol could reach up to76.9%and the selective for benzyl ether could be as high as96.1%. Besides, the benzoylation of anisole with clean reagent benzoic acid over theabove prepared heteropoly-organic hybrids catalysts has been also studied.The above prepared heteropoly-organic hybrids catalysts have been found to exhibithigh catalytic activity and reusability in the Friedel-Crafts reaction and dehydrationreaction. The results in this paper provide a way to develop novel acidic catalysts.