title: Quantum-chemical investigation of second-order nonlinear optical chromophores: comparison of strong nitrile-based acceptor end groups and role of auxiliary donors and acceptors.
abstract: We report a detailed quantum-chemical investigation of donor-acceptor substituted dipolar nonlinear optical chromophores incorporating the 4-(dimethylamino)phenyl donor end group and a variety of strong heterocyclic acceptor end groups, including tricyanofurans and tricyanopyrroles. In particular, we study the variation of the molecular second-order polarizability (beta) with the acceptor end group and when inserting auxiliary donors (thiophene) and acceptors (thiazole) into the pi bridge. Both finite-field calculations (in the context of local contributions) and sum-over-states calculations were carried out in order to probe the relationship between beta and the chemical structure of the various chromophores. The trends obtained with these two methods are fully consistent. The large beta values (up to 700 x 10(-30) esu) as well as the observed tunability of the optical absorption maximum (lambda(max)) make the chromophores investigated here interesting candidates for use in electro-optic applications at telecommunications wavelengths.
authors.affiliation: School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
authors.forename: A
authors.initials: A
authors.lastname: Leclercq
authors.forename: E
authors.initials: E
authors.lastname: Zojer
authors.forename: S-H
authors.initials: SH
authors.lastname: Jang
authors.forename: S
authors.initials: S
authors.lastname: Barlow
authors.forename: V
authors.initials: V
authors.lastname: Geskin
authors.forename: A K-Y
authors.initials: AK
authors.lastname: Jen
authors.forename: S R
authors.initials: SR
authors.lastname: Marder
authors.forename: J L
authors.initials: JL
authors.lastname: Brédas