Study on the structure–performance relationship of nonlinear optical chromophores with different donors, bridges, and acceptors

Abstract

Three series of high-performance nonlinear optical chromophores, B-TCF, B-3F, B-5F, N-TCF, N-TCF, S-TCF, and S-3F–S-5F, were synthesized using triphenylamine and N,N-bis-(4-methoxyphenyl)arylamine as donors, tetraene and thiophene as bridges, and tricyanofuran (TCF), perfluorophenyl-tricyanofuran (5F-TCF) and phenyl-trifluoromethyl-tricyanofuran (3F-TCF) as acceptors. We conducted a comprehensive analysis of these three series of chromophores to elucidate the structure–performance relationship from various perspectives. By employing DFT calculations and electro-optical coefficient tests, we observed significant influences of different electron donors, π-conjugated bridges, and acceptors on the performance of the chromophores. Polymeric thin films doped with chromophores N-3F and N-5F of 25 wt% with the N,N-bis-(4-methoxyphenyl)aryl-amino donor have been poled to afford large r₃₃ values of 198 and 171 pm V⁻¹ at 1.31 μm, respectively, which surpassed those obtained with other chromophores.