Ab-initio calculations on static and dynamic third-order optical nonlinearity of azo-azulenes

To provide an insight into the microscopic third-order nonlinear optical (NLO) behavior of a series of azo-azulenes; both dispersion-free (static) and also frequency-dependent (dynamic) linear polarizabilities (alpha) and second hyperpolarizabilities (gamma) at 532nm wavelength have been theoretically investigated by means of a time-dependent Hartree-Fock (TDHF) method. The maximum one-photon absorption (OPA) wavelengths recorded by quantum mechanical computations using a configuration interaction (CI) method are estimated in the visible region, supporting the pi ->pi* transitions. The ab-initio calculation results with non-zero values on (hyper) polarizabilities indicate that the title compounds might possess microscopic third-order NLO phenomena.