Charles K. Baker

Synthesis and optical properties of an oligothiophene-based liquid crystal

We report on the synthesis and characterization of an asymmetrically substituted oligothiophene, 2-cyano-5-octylquarterthiophene (CN-4T-Oct), which is shown below. The preliminary work to characterize this molecule indicates that it exhibits a complex liquid crystalline behavior which may lead to the ability to modulate the optical and electrical properties as a function of molecular order. Solution based electrochemical and optical characterization indicates that this material is readily doped to form electronic states required for charge carrier formation and modulation of the optical properties.

Optical properties of poly(2,5-dimethoxy-1,4-phenylene vinylene-co-2,5-thienylene vinylene) copolymer films and solutions

Abstract A copolymer system, poly(2,5-dimethoxy-1,4-phenylene vinylene-co-2,5-thienylene vinylene), prepared form various monomer feed ratios has been synthesized via a soluble precursor method. By preparing this copolymer, we hoped to achieve control, and hopefully reduction, of the bandgap relative to the parent homopolymers. In addition, the introduction of asymmetry into the backbone and the reduced bandgap should lead to materials with enhanced nonlinear optical properties. Optical absorption measurements on films and chloroform solutions of the eliminated copolymer systems indicate that the electronic and optical properties are intermediate to the parent homopolymers. Nonlinear optical absorption measurements show a power limiting effects indicating that these materials may be good candidates for more extensive NLO measurements.