Enhanced molecular first hyperpolarizability in s-triazine derivatives: Combined experimental and computational studies

•Linear and nonlinear optical properties of a series of molecules have been studied.•Enhanced molecular β in the molecules with a very week donor-acceptor system.•These molecules are transparent in the visible region, which is suitable for application in the region of interest.

Molecular first hyperpolarizabilities (nonlinear optical responses) of selected s-triazine based heteroaromatic molecules are determined using experimental methods. A large enhancement in nonlinear optical response, in spite of a relatively weak donor–acceptor system, is observed. We have carried out a detailed analysis using computational chemistry techniques to account for this behavior.