title: Effect of donor-acceptor substitution on the nonlinear optical properties of oligo(1,4-phenyleneethynylene)s studied by third harmonic generation spectroscopy.
abstract: Third-harmonic generation (THG) spectroscopy was performed for oligo(1,4-phenyleneethynylene)s (OPEs) with terminal donor-acceptor (DA) substitution and compared to the results of merely donor substituted OPEs and regular OPE chains with 2,5-dipropoxy benzene rings. Both, extension of the conjugation and push-pull effect enhance the molecular hyperpolarizability gamma, even for the DAOPEs, which exhibit a hypsochromic shift of the long-wavelength absorption for increasing length L of the conjugated chain.
authors.affiliation: Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany. koynov@ mpip-mainz.mpg.de
authors.forename: Kaloian
authors.initials: K
authors.lastname: Koynov
authors.forename: Ayi
authors.initials: A
authors.lastname: Bahtiar
authors.forename: Christoph
authors.initials: C
authors.lastname: Bubeck
authors.forename: Bastian
authors.initials: B
authors.lastname: Mühling
authors.forename: Herbert
authors.initials: H
authors.lastname: Meier