We present calculations on the geometry of the first 1Bu excited state in polyene chains ranging in length from 5 to 29 double bonds. Calculations are performed in the framework of a Hückel Hamiltonian with bond-length-dependent transfer integrals and with σ-bond compressibility and use the parameters originally chosen for polyacetylene. Our results indicate that there is a smooth evolution of the 1Bu excited state geometry relaxation on going from short to long chains. In all cases, we find that the 1Bu excited state geometry tends to relax in such a way as to produce a pair of soliton defects. The implications of our results for the nonlinear optical properties of polyenes are discussed.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry