Intermolecular charge transfer between heterocyclic oligomers. Effects of heteroatom and molecular packing on hopping transport in organic semiconductors

Geoffrey R. Hutchison, Mark A. Ratner, Tobin J. Marks

Research output: Contribution to journalArticle

345 Citations (Scopus)

Abstract

For electron or hole transfer between neighboring conducting polymer strands or oligomers, the intrinsic charge-transfer rate is dictated by the charge-resonance integral and by the reorganization energy due to geometric relaxation. To explain conduction anisotropy and other solid-state effects, a multivariate, systematic analysis of bandwidth as a function of intermolecular orientations is undertaken for a series of oligoheterocycles, using first-principles methods. While cofacial oligomers show the greatest bandwidths at a given intermolecular C-C contact distance, for a fixed center-to-center intermolecular distance, tilted π-stacking increases π-overlap (particularly for LUMO orbitals) and decreases electrostatic repulsion, yielding optimum tilt angles for packing of ∼40-60° at small intermolecular separations. The calculations also reveal that bandwidths and intrinsic mobilities of holes and electrons in conjugated oligoheterocycles can be quite comparable.

Original languageEnglish
Pages (from-to)16866-16881
Number of pages16
JournalJournal of the American Chemical Society
Volume127
Issue number48
DOIs
Publication statusPublished - Dec 7 2005

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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