Publications [#231978] of David N. Beratan
Journal Articles
- Beratan, DN, "Influence of gap states on the nonresonant second hyperpolarizabilities of conjugated organic polymers", Journal of physical chemistryJanuary,, 1989, 93(10), 3915-3920, American Chemical Society (ACS) [pdf], [doi].
(last updated on 2024/04/15)Abstract:
The presence of conjugation and substitution defects introduces 'gap states' in finite polyenes that are shown to influence the size and sign of the second molecular hyperpolarizability, γxxxx. Using a one-electron tight-binding model, we calculate the dependence of γxxxx on the defect-state occupancy and energy in finite polyenes. Defects can cause a significant decrease or enhancement of γxxxx by impeding charge delocalization or by creating partly filled bands (mimicking the one-band limit), respectively. Concomitant sign changes in γxxxx are predicted. Calculations of these effects are made for molecules in which a central atom's identity and electron occupancy are varied. The results suggest strategies for designing molecules that can be either photochemically or electrochemically switched between states with considerably different second hyperpolarizabilities.