We investigate the longitudinal static second hyperpolarizability (γ) of open-shell singlet diphenalenyl radical dimer using the spin-unrestricted density functional theory method. This dimer is known to be a model unit of a slipped stacked linear chain with an unusually short average π-π distance of 3.137 Å. The longitudinal γ per monomer for this dimer is found to be significantly (about twice) enhanced as compared to that of monomer. This originates in the field-induced intermolecular virtual charge transfer between both-end phenalenyl rings through the strong covalent interaction between the unpaired electrons of the cofacial phenalenyl rings.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry