New sulfonyl-containing materials for nonlinear optics: semiempirical calculations, synthesis, and properties

In this study the authors describe semiempirical calculations, synthesis, ground-state dipole moment measurements, and measurements of molecular second-order hyperpolarizability coefficients ({beta}) for new stilbene and azobenzene derivatives containing a methylsulfonyl group as the electron acceptor. They show that theoretical calculations can be used to predict the trends for molecular hyperpolarizabilities between similar compounds and that these gas-phase calculations underestimate {beta} values, probably as a result of the valence basis set used in the calculations. Whereas the sulfone group has been demonstrated to give molecular hyperpolarizabilities somewhat less than those of similar nitro compounds, the difference becomes less as the degree of conjugation is increased. The increased transparency in the visible spectrum and the synthetic flexibility may make sulfonyl compounds important for some applications.