title: Steps to demarcate the effects of chromophore aggregation and planarization in poly(phenyleneethynylene)s. 1. Rotationally interrupted conjugation in the excited states of 1,4-bis(phenylethynyl)benzene.
abstract: A series of photophysical measurements and semiempirical calculations were carried out with 1,4-bis(phenylethynyl)benzene in search of evidence on the effects of phenyl group rotation and chromophore aggregation of oligo- and poly(phenyleneethynylene)s. It is suggested that planarization gives rise to relatively modest shifts of ca. 20-30 nm, which preserve the vibronic structure of the monomer and retain a high emission quantum yield. In contrast, it is proposed that aggregation gives rise to larger shifts and loss of vibronic structure.
authors.affiliation: Departments of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
authors.forename: M
authors.initials: M
authors.lastname: Levitus
authors.forename: K
authors.initials: K
authors.lastname: Schmieder
authors.forename: H
authors.initials: H
authors.lastname: Ricks
authors.forename: K D
authors.initials: KD
authors.lastname: Shimizu
authors.forename: U H
authors.initials: UH
authors.lastname: Bunz
authors.forename: M A
authors.initials: MA
authors.lastname: Garcia-Garibay