Effect of Donor/Acceptor group position on the NLO properties of branched chain organic molecules

The organic materials are the most investigated materials for their nonlinear optical properties in the past three decades. In this article the systematic investigation on the NLO properties of Donor/Acceptor substituted branched chain organic chromophores, chalcones, using semi empirical method is presented. The nonlinear optical molecular static first hyperpolarizability (β) was found to be larger for Donor/Acceptor group substituted at para position than that of substitution of Donor/Acceptor group at meta and ortho position. For designing NLO materials with high β it is recommended to make substitution of Donor/Acceptor group at para position rather than meta and ortho position.