Through structural design, a series of bifunctional ionic liquids (BFILs) containing sulfonic acid (–SO₃H) and sulfhydryl groups (–SH) were synthesized and characterized by NMR and MS. The acidity of these BFILs was measured by the Hammett acidity (H₀) and the effective sulfhydryl molar content of BFILs was determined by Ellman's method. Moreover, BFIL's catalytic properties in the condensation reaction of 9-fluorenone and phenol were studied. BFIL catalyst 6c can achieve nearly 100% conversion of 9-fluorenone with a high selectivity of 9,9-bis(4-hydroxyphenyl) fluorene (95.2%).

中文翻译：

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双功能离子液体催化合成9,9-双(4-羟基苯基)芴

通过结构设计，合成了一系列含有磺酸（-SO ₃ H）和巯基（-SH）的双功能离子液体（BFILs），并通过NMR和MS对其进行了表征。这些BFILs的酸度通过Hammett酸度( H ₀ )测量，BFILs的有效巯基摩尔含量通过Ellman法确定。此外，还研究了BFIL在9-芴酮与苯酚缩合反应中的催化性能。BFIL催化剂6c可以实现近100%的9-芴酮转化率，9,9-双(4-羟基苯基)芴的选择性高(95.2%)。