Conjugational defect in trans-polyacetylene and its ESR and ENDOR lineshapes

Abstract

It is shown that the analysis of the ESR spectrum does not define unambiguously, the spin-density distribution of the conjugational defect in trans-polyacetylene. Exact expressions for the ESR lineshape, appropriate to protonated and deuterated polyacetylene, are derived and a few physically relevant spin-density distributions are considered to exemplify the above point. On the other hand, the analysis of the ENDOR spectrum using a simplified expression is shown to be much more sensitive to the choice of the spin-density distribution function for the conjugational defect.