Single, Double Electronic Excitations and Exciton Effective Conjugation Lengths in π-Conjugated Systems.

Published

Journal Article

The 21Ag and 11Bu excited states of two prototypical π-conjugated compounds, polyacetylene and polydiacetylene, are investigated with the recently developed particle-particle random phase approximation (pp-RPA) method combined with the B3LYP functional. The polymer-limit transition energies are estimated as 1.38 and 1.72 eV for the 21Ag and 11Bu states, respectively, from an extrapolation of the computed excitation energies of model oligomers. These values increase to 1.95 and 2.24 eV for the same transitions when ground-state structures with ∼33% larger bond length alternation are adopted. Applying the pp-RPA to the vertical excitation energies in oligodiacetylene, the polymer-limit transition energies of the 21Ag and 11Bu states are computed to be 2.06 and 2.28 eV, respectively. These results are in good agreement with experimental values or theoretical best estimates, indicating that the pp-RPA method shows great promise for understanding many photophysical phenomena involving both single and double excitations.

Full Text

Duke Authors

Cited Authors

  • Sutton, C; Yang, Y; Zhang, D; Yang, W

Published Date

  • July 6, 2018

Published In

Volume / Issue

  • 9 / 14

Start / End Page

  • 4029 - 4036

PubMed ID

  • 29939751

Pubmed Central ID

  • 29939751

Electronic International Standard Serial Number (EISSN)

  • 1948-7185

International Standard Serial Number (ISSN)

  • 1948-7185

Digital Object Identifier (DOI)

  • 10.1021/acs.jpclett.8b01366

Language

  • eng