No abstract

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 (2) ( ) χ for the examined compounds. The calculated results on dynamic (2) ( ) χ are quite consistent with the previous experimental observations.

To investigate dispersion-free third-order nonlinear optical (NLO) behaviour of a series of ruthenium complexes, static dipole polarizabilities ( ) α and second hyperpolarizabilities ( ) γ have been determined by time-dependentHartree-Fock (TDHF) method. To provide an insight into the frequency-dependent third-order NLO phenomena of the title compounds, the dynamic dipole polarizabilities and second hyperpolarizabilities using TDHF procedure have been also computed at the wavelengths used in third-harmonic generation (THG) measurements. According to the computation results, the examined molecules exhibit second hyperpolarizabilities with non-zero values, implying microscopic third-order NLO behaviour. To compare our theoretical results on third-order NLO manner with corresponding experimental data, we also give the calculation results of the dynamic third-order susceptibilities (3) ( ) χ for the studied complexes.