Synthesis and Characterization of Sterically Stabilized Second-Order Nonlinear Optical Chromophores

Bulky substituents added to second-order nonlinear optical (NLO) chromophores inhibit intermolecular electrostatic interactions that attenuate electric poling induced macroscopic electrooptic activity. Such chromophore modification also improves chemical and photochemical stability and the processability of chromophores into hardened, optical-quality polymer materials by improving solubility. We present a new route to the synthesis of electrooptic (second-order NLO) chromophores based on sterically protected π-electron bridge structures, yielding molecules exhibiting both large optical nonlinearity and good thermal stability.