Second-order hyperpolarizability and susceptibility calculations of a series of ruthenium complexes

The ab-initio quantum mechanical calculations (time-dependent Hartree-Fock (TDHF) method) of a series of ruthenium complexes have been carried out to compute electric dipole moment (μ), dispersion-free and frequency-dependent first hyperpolarizability (β) values. The one-photon absorption (OPA) characterizations have been also theoretically investigated by means of configuration interaction (CI) method. Our calculated results on the maximum OPA wavelengths and second-order hyperpolarizabilities are in good agreement with the observed values in the literature. According to the results of the TDHF calculations, the investigated molecules exhibit non-zero β values, and they might have microscopic second-order nonlinear optical (NLO) behaviour. We also give the computational results of the frequency-dependent second-order susceptibilities (χ (2) ) for the examined compounds. The calculated results on dynamic (χ (2) ) are quite consistent with the previous experimental observations.