Second-order nonlinear response in mono- and di-substituted triazine derivatives: A combined experimental and theoretical analysis

Several mono- and di-substituted triazine derivatives are synthesized. Their molecular first hyperpolarizability (β) and absorption properties are determined. The observed trends in the β values obtained from the experiments as well as from the theory are in good agreement. In moving from mono- to di-substituted triazine derivatives the absorption maximum (λmax) shows a negligible shift, but the β values are enhanced. In most of the cases the dipole moment decreases with increasing substitution. With these advantages new trends for the molecular design of s-triazine compounds for second-order NLO applications are proposed.