New Description of the Substituent Effect on Electronic Spectra by Means of Substituent Constants. III. Charge Transfer Spectra of Eda Complexes

Abstract

General equations in order to describe the electronic spectra by means of substituent constants were derived on the basis of molecular orbital theory. The most suitable substituent constants are theoretically Swain's F and R constants, but Yukawa-Tsuno's parameter is also useful for π-electron system. In this paper these equations were applied to explain the charge transfer spectra of π-π type EDA complexes composed of TCNE and various kinds of aromatic donors. The results have been quite reasonable and discussed in detail.