新型Br鴑sted-Lewis双酸性离子液体的合成及其催化松香二聚反应

Synthesis of Novel Br鴑sted-Lewis Acidic Ionic Liquids and Used as Catalysts in Rosin Dimerization

摘要:

以盐酸为B酸供体将N-甲基咪唑(mim)质子化得到Brønsted酸性离子液体mim•HCl，继续与Lewis酸供体FeCl3反应合成了一族Brønsted-Lewis双酸性离子液体氯化-1-氢-3-甲基咪唑氯铁酸盐(1-x)[mim•HCl]x[FeCl3]，式中x为Lewis酸所占的摩尔分数。分别用吡啶和乙腈探针红外光谱表征和比较了其酸性，并将其应用于催化松香的二聚反应。所合成的一族双酸性离子液体中， (1-x)[mim•HCl]x[FeCl3](x=0.64)催化松香二聚反应时，二聚产物的软化点比空白样品提高了15 oC；其催化活性在重复利用5次后才开始下降。

Abstract:

A Brønsted acidic ionic liquid mim•HCl was synthesized as an intermediate by protonating N-methyl imidazole with Brønsted acid donor hydrochloric acid. And a group of dual acidic ionic liquid 1-hydro-3-methylimidazole chloride chloroironinates (1-x)[mim•HCl]x[FeCl3] (where x is the mole fractions of the Lewis acid) was synthesized from the reaction of mim•HCl and a Lewis acid donor FeCl3. The acidities of the group were characterized and compared to each other by FT-IR in virtue of pyridine and acetonitrile molecular probe, respectively. The dual acidic ionic liquids were then employed to catalyze rosin dimerization. A dimeric rosin acid with a softening point of 102.4 oC was obtained using (1-x)[mim•HCl]x[FeCl3](x=0.64) as catalyst, which was 15 oC higher than that without using catalyst. The catalytic activity became weaker after the fifth use.