指示剂蒸气法测定固体超强酸酸强度

介绍了一种采用Hammett指示剂测定固体超强酸酸强度的简便方法。指示剂溶液的蒸气与活化后的固体超强酸试样在真空条件下接触,既可以避免因固体超强酸与水蒸气接触而失活,又可以使固体酸与指示剂充分接触,提高了测试灵敏度。该方法可同时测定多个试样,测试效率高。实验表明,不同条件下制备的固体超强酸使酸强度pKa=-11.99~-14.52的指示剂的变色情况不同,采用红外光谱方法对此现象进行了解释。

Steam Method of Determining Acid Strength of Solid Superacids

An available method was introduced to measure acid strength of solid superacid with Hammett indicator.In measurement and test,solid superacid samples reacted with indicator vapor in vacuum.So contact of samples with water vapor could be avoided and solid superacid could maintain its activity.Besides several samples can be tested simultaneously in a single experiment.Hammett indictors (pKa from -11.99 to -14.52) performed differently when they contacted superacids prepared under different conditions.IR spectrum was used to explain the phenomenon.The method was sensitive,efficient and valuable in research of solid superacids.