Donor-Acceptor Styrylisoxazoles: Solvatochromism and Large First Hyperpolarizability

The present work describes the synthesis and linear as well as nonlinear optical studies of donor-acceptor based styrylisoxazoles. Six styrylisoxazoles were synthesized, and examination of their photophysical properties reveals strong solvent polarity sensitivity due to intramolecular charge transfer characteristics. Most interestingly, we have measured large first hyperpolarizability (β) values for these styrylisoxazoles. The largest β value calculated was for the compound that bears the dimethylamine group as the donating moiety. Our current results suggest that a careful selection of the donor and acceptor groups can potentially lead to unprecedented enhancement of the (β) values of isoxazole derivatives.