Effective conjugation length and UV/vis spectra of oligomers

Abstract

Abstract On the basis of an extended series of monodisperse oligomers of the dialkoxy‐substituted phenyleneethenylenes 1a–i the Eqs. (3) and (4) were conceived in order to determine the limiting values of the energies E i and the wavelengths λ i of the UV/vis absorption. The convergence of the E i , and λ i values with a growing number n of repeating units permits a precise prediction of the E i ,∞ and λ i ,∞ values of the corresponding polymer 1j as well as a statement about the overall effect of conjugation Δ E i and the effective conjugation length ECL. A great variety of different conjugated oligomers 2–14 can be evaluated by the same algorithm.