Calculations are reported on the structure of donor-acceptor phenylazobenzenes, phenylazonaphthalenes, phenylazoanthracenes, and phenylazoheterocycles using the AM1 molecular orbital method. The spectra and hyperpolarizabilities of these systems have been calculated using a modified version of the sum-over-states CNDOVSB method specifically parameterized for electro-optic modulation. The replacement of one phenyl ring of the phenylazobenzenes by naphthalene or anthracene results in a modest increase in the hyperpolarizability but the value obtained is highly dependent on the position of the donor group and the tautomeric form. Enhanced values are obtained when a heterocyclic ring is incorporated into the azoarene with the largest value obtained for a donor-acceptor naphthylazothiophene. Substantial resonance enhancement effects occur for those derivatives which absorb in the red or infrared region of the spectrum.

Date Published: 25 February 1993
PDF: 11 pages
Proc. SPIE 1775, Nonlinear Optical Properties of Organic Materials V, (25 February 1993); doi: 10.1117/12.139189

Published in SPIE Proceedings Vol. 1775:
Nonlinear Optical Properties of Organic Materials V
David J. Williams, Editor(s)