新型苯并咪唑杂多酸盐离子液体的制备及其在催化合成己二酸中的应用

以1-丁基苯并咪唑为起始原料,合成了1-丁基-3-(4-磺酸基丁基)苯并咪唑內盐(1),1-丁基-3-羧甲基苯并咪唑氯盐(2)和1,3-二丁基苯并咪唑溴盐(3);1~3分别与硅钨酸、磷钨酸和磷钼酸在水或者乙醇中反应,合成了5种新型的杂多酸盐离子液体——1-丁基-3-(4-磺酸基丁基)苯并咪唑硅钨酸盐(4a),1-丁基-3-(4-磺酸基丁基)苯并咪唑磷钨酸盐(4b),1-丁基-3-(4-磺酸基丁基)苯并咪唑磷钼酸盐(4c),1-丁基-3-羧甲基苯并咪唑硅钨酸盐(5)和1,3-二丁基苯并咪唑硅钨酸盐(6),其结构经1H NMR,13C NMR和IR表征。并考察了4~6在30%H_2O_2催化氧化环己烯制备己二酸反应中的催化效果。实验结果表明:4b的催化效果最好。在最佳反应条件[环己烯20 mmol,4b 0.16 mmol,n(环己烯)∶n(H2O2)∶n(ILs)=1∶4.4∶0.008]下,己二酸产率71%。

Preparation of Novel Benzimidazole Heteropolyanion-based Ionic Liquids and Their Application in the Catalytic Synthesis of Adipic Acid

Five novel heteropolyacid-based ionic liquids [BSbBim]4SiW12O40(4a), [BSbBim]3PW12 O40(4b), [BSbBim]3PMo12O40(4c), [CMbBim]4SiW12O40(5) and [BbBim]4SiW12O40(6) were synthesized by reaction of heteropolyacid with [ BSbBim ] ( 1 ) , [ CMbBim ] Cl ( 2 ) and [ BbBim ] Br (3), which were prepared from 1-butyl-1H-benzo[d]imidazole.The structures were characterized by 1 H NMR, 13 C NMR and IR.Oxidation of cyclohexene to adipic acid with hydrogen peroxide catalyzed by 4~6 were investigated.And the results showed that 4b has the best catalytic activity.The yield of adipic acid was up to 71%under the optimized conditions that cyclohexene was 20 mmol, 4b was 0.16 mmol, n(cyclohexene) ∶n(H2O2) ∶n(ILs) was 1 ∶4.4 ∶0.008.