- 作者: 劉廣定,秦建譜,郭曼?
- 作者服務機構: Department of Chemistry, National Taiwan University, Taipei, Taiwan 10617, R.O.C.
- 中文摘要: The solvolysis of a series of 1-aryl-2,2-dimethyl-1-phenyl-1-propyl p-nitrobenzoates (6a-6g) in a variety of solvents were studied. Both the single-parameter Hammett-Brown equation (Eqn. 1) and the dual-parameter Yukawa-Tsuno equation (Eqn. 2) showed excellent linear correlations, although inverse order of k(p-CF3)/k(m-CF3) was realized in five different solvent systems. A similar result was also found in 3-aryl-2,2,4,4-tetramethyl-3-pentyl p-nitrobenzoates (5) in 80% acetone. The result of Grunwald-Winstein type correlation analysis against YBnOPNB or YxBnOPNB showed ambiguity for interpretation. It provides more evidence for the lack of coplanarity between the aryl ring and the sp2 plane at the cationic transition state, and thus an insignificant resonance contribution from the aromatic moiety. A comprehensive collection of published data is tabulated.
- 英文摘要: --
- 中文關鍵字: 1-Aryl-1-tert-butyl-1-phenylmethyl p-nitrobenzoates; Grunwald-Winstein equation; Hammett plots; s+ constants; Yukawa-Tsuno treatment; Rate ratios; k(p-CF3)/k(m-CF3).
- 英文關鍵字: --