Nonlinear optical properties of fluorobenzenes: A Time-Dependent Hartree–Fock study

Second-order electronic hyperpolarizabilities (γ) of benzene and fluorobenzenes were computed using Hartree–Fock and correlated second-order Møller–Plesset perturbation theory (MP2) with the Sadlej’s POL basis set. Dynamic γ values were determined for the nonlinear optical (NLO) Third Harmonic Generation process at the wavelength of 1910 nm. The results show that, differently from the electronic polarizabilities, the average 〈γ〉 values steadily decrease with the increase of the number of fluorine atoms, following a near-additive atomic contribution law. At the MP2/POL level 〈γ〉(C6H6) is predicted to be ca. four times greater than 〈γ〉(C6F6). Fluorination produces disadvantageous contributions for third-order NLO properties of π-conjugated materials.