Computational studies on linear, second and third-order nonlinear optical properties of novel styrylquinolinium dyes

Abstract The electric dipole moments ( μ ), static dipole polarizabilities ( α ) and first hyperpolarizabilities ( β ) of styrylquinolinium dyes, D8 and D21 , have been computed by density functional theory (DFT). The one-photon absorption (OPA) characterizations have been investigated using UV–vis spectroscopy and further interpreted using computational chemistry. The time-dependent Hartree–Fock (TDHF) method has been used to describe the dynamic dipole polarizabilities, dynamic second-order and also static and dynamic third-order nonlinear optical (NLO) properties. D8 – D21 have rather high β and second hyperpolarizabilities ( γ ). The highest occupied molecular orbitals (HOMO), the lowest unoccupied molecular orbitals (LUMO) and the HOMO–LUMO band gaps for D8 – D21 have been evaluated by DFT.