The New Substituent Constants in the Excited States (￥±)

摘要

In order to standardize the ヲ*, ヱ* is taken as unity for the benzoic acids by analogy with the fact that ヱ of benzoic acids in the ground state is taken as unity. The pKa* of many benzoic acid derivatives are determined by UV spectroscopy and fluorescence spectral analysis whenever possible. The ヲ* constants are derived from the Hammett equation utilizing these pKa* values and the pKa* of the benozic acid derivatives showed better correlationship with ヲ* than ヲ, ヲ+ and ヲ- as expected. From these ヲ* values, ヱ* of the phenol derivatives was calculated to be 1.28. The new standardized ヲ* values are calculated from the pKa* values of phenols since more accurate and abundant data are available for phenols than the benzoic acid derivatives.