Syntheses of four new pyridinium phenolates with caged phenolate functionalities as chromophores for quadratic optics

Semi-empirical calculations as well as our preliminary studies indicate an increase of the nonlinear response of pyridinium phenolates with the raise of their interplanar angle. Unfortunately, the tendency of previously synthesized zwitterionic compounds to form aggregates prevents their use in electro-optical devices. In order to understand the process of aggregation and to circumvent it, the syntheses of new pyridinium phenolates bearing alkyl chains of various length, caging the phenolate functionality, have been achieved and are described herein.