Particle in a One-Dimensional Box as a Model for the Description of Conjugated Systems

Abstract

The usual «particle in a one-dimensional box» model for the description of the first absorption band of conjugated polyenes is criticized because it leads to the wrong prediction that the energy of the highest occupied molecular orbital (HOMO) is independent of the chain length, which means that the redox potential change for the oxidation of these dyes with increasing chain length cannot be described. It is shown how this serious deficiency of the otherwise still very useful model can be eliminated without loss of simplicity.