咪唑类氮氧自由基的ESR波谱的酸度相关性─pH自旋探针应用研究之一(英文)

THE INFLUENCE OF MEDIUM ACIDITY ON THE ESR SPECTRA OF IMIDAZOLINE NITROXIDE RADICALS:The Application Research of pH Spin Probes Ⅰ

根据咪唑类氮氧自由基的结构特性合成了一系列的pH自旅探针，其ESR波谱参数均在一定范围内与介质的酸性呈明显的相关性．可望为较精确地测量化学胶束、细胞等微观体系的pH值开辟一个新的途径．本文研究了灵敏变化的pH范围与取代基的关系，得到了5种自旅探针的ESR参数-pH曲线、pKa值以及Hanmmett相关图，分析了如何通过改变取代基合成出不同pH变化范围并适用于不同生物和化学体系的pH自旅探针，最终达到付诸应用的目的．

Imidazoline nitroxide radicals were synthesized and studied as 'pH probes'.The influence of pH on the ESR spectra of the radicals were discussed and their pKa valueswere measured. The substituent R on the phenyl ring has an effect on the proton exchangerate of the N3 atom which is related to the pKa value of the nitroxide radical.