title: Coplanarity in the backbones of ladder-type oligo(p-phenylene) homologues and derivatives.
abstract: p-Tolyl-substituted ladder-type oligo(p-phenylene)s containing three, four, and five phenylene rings were readily synthesized. The uniform aryl substitution of these systems allowed us to determine the coplanarity of the pi-conjugated backbones crystallographically. The intramolecular annulations eliminate almost all of the conformational disorder and enhance the degree of pi-conjugation of the backbones, resulting in significant red shifts in the absorption and emission maxima and lower oxidation potentials in the higher homologues. [structure: see text]
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 106, Taiwan. kenwong@ntu.edu.tw
authors.forename: Ken-Tsung
authors.initials: KT
authors.lastname: Wong
authors.forename: Liang-Chen
authors.initials: LC
authors.lastname: Chi
authors.forename: Shih-Chiang
authors.initials: SC
authors.lastname: Huang
authors.forename: Yuan-Li
authors.initials: YL
authors.lastname: Liao
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang