Synthesis and characterization of poly(p-phenylene)s with nonlinear optical side chains

A highly substituted side chain NLO poly(p-phenylene) (similar to 70.1 wt % NLOphore) has been prepared by the nickel-catalyzed coupling of 4'-(N,N-diethylamino)-2,5-dichlorobenzophenone. Poly((4'N,N-diethylamino)-2,5-benzophenone), PDEABP, is a modest molecular weight material (M-n= 5300) that is thermally stable up to 400 degrees C with a glass transition temperature of 186 degrees C. The system showed virtually no decay of SHG at 100 degrees C hours after removal of the corona poling field. A stretched exponential was used to fit the relaxation data. At 170 degrees C, the SHG decayed to 1/e of its initial value with a relaxation time of tau = 120 min. PDEABP exhibits a nonlinear coefficient of d(33) = 67.8 +/- 20 pmN.