Theoretical investigation of the nonlinear optical properties of substituted anilines and N,N-dimethylanilines

Abstract The nonlinear optical (NLO) properties of a series of anilines and N , N -dimethylanilines are studied with second-order Moller–Plesset perturbation theory (MP2). The effect of solvents on the calculated NLO properties is investigated by considering a wide range of solvent systems within the polarizable continuum model. In order to identify systems with high first-order hyperpolarizability, the effects of four basic variations to the molecules on the calculated NLO properties are studied. The modifications comprise changes to the donor strength (NH 2 to N(CH 3 ) 2 ), changes to the acceptor strength (NO 2 , CN and CHO), variation of additional substituents (H, CH 3 , Br, OCH 3 ), and changes in the conjugation length. It is found that the first-order hyperpolarizability increases when the compounds have N , N -dimethyl as donor, vinyl nitro group as acceptor at the 4-position, and a methoxy group as substituent at the 2-position.