New Approaches to the Synthesis of Ladder Polymers: Copolymers of Aniline and Thiophene

We would like to report the synthesis of new third order nonlinear optical materials formed from reaction of dibromothiophenes with p-phenylenediamines under Ullmann condensation conditions. Initial measurements of the third harmonic NLO susceptibilities (X3~= 4 × 10−10 esu ), high laser damage thresholds ( 4 GW/cm2 ), and low absorptions have provided promising materials for device applications. Composite films in poly(vinylalcohol), poly(methylmethacrylate). or poly(carbonate) also gave significant X3 values in less than 10 percent w/w concentrations.