- 作者: 劉廣定 ; 許宏彰
- 作者服務機構: 台灣大學化學系
- 中文摘要: Solvolysis of 2-bromo-2-(4'-fluoromethyl)phenyladamantane (4) and 2-bromo-2-(4'-trifluoromethyl)phenylpropane (5) were carried out in a number of solvents, and their rate constants measured. Significant deviation from linear log k-Y/sub Br/ plots was observed, and the order of reactivities, e.g., k(100M)>k(90E)>k(80A), was in the reverse order of Swain's solvent parameter B. Different extent of solvation to the localized and the delocalized cationic transition state was then likely to play an important role. Similar result was also found in the solvolysis of 1-bromo-2,2,2-trifluoro-1-(4'-methylphenyl)-1-phenylethane. A new Y scale, Y/sub BnBr/, for the correlation of solvolytic reactivities of benzylic bromides based on K(4) was established. Intervention of solvent assistance in the solvolysis of 5 is discussed.
- 英文摘要: --
- 中文關鍵字: Benzylic Bromide; Nucleophilic Solvent; Swain's Solvent Parameter; Solvolysis; Winstein-Grunwald Equation; Reaction Rate Constant
- 英文關鍵字: 溴甲苯;親核溶劑;Swain溶劑參數;溶劑分解;Winstein-Grunwald方程式;反應速率常數