电子自旋共振作为探针研究卤代溶剂的专属性效应  

Investigation on Specific Effect of Halogenated Solvents by ESR Probe

作　　者：庞雪[1] 申前进[1] 赵晓冉[1] 晋卫军[1] 

机构地区：[1]北京师范大学化学学院,北京100875

出　　处：《化学学报》2011年第11期1375-1380,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.20675009;90922023);北京市自然科学基金(No.2093037)资助项目

摘　　要：4-羟基-2,2,6,6-四甲基哌啶-1-氧自由基(4-OH-TEMPO)电子自旋共振的超精细耦合常数AN与溶剂极性的微观反应常数ET(30)和溶剂受体数AN呈现线性正相关.并且在介电常数或偶极矩接近时,含卤溶剂中超精细耦合常数AN普遍偏高.除了一般的溶剂效应外,在含卤溶剂中超精细耦合常数AN偏大的原因与专属性的卤键作用有关.理论计算结果辅助印证了这一结论.The hyperfine splitting constants,AN,of electron spin probe,4-hydroxy-2,2,6,6-tetramethyl-1piperidin-1-yloxy,free radical（4-OH-TEMPO） show positive linear correlation with model reaction pa-rameters of solvent polarity,ET（30） and solvent acceptor number（AN）.Moreover,generally,AN values are higher in halogenated than non halogenated solvents as dielectron constant or dipole moment is near.Be-sides the general solvent effect on AN values,larger AN values can be attributed to the specific halo-gen-bonding between N-O free radical and halogenated solvent molecule.The calculation shows the oc-currence of C-Cl…O between chloroform or dichloromethane and free radical molecules.

关 键 词：卤键 电子自旋共振 专属性溶剂效应 含卤溶剂 溶剂受体数 

分 类 号：R914[医药卫生—药物化学]