Theoretical study of solvent effect on the structure, first electronic excited state, and nonlinear optical properties of substituted stilbazolium cations

Molecular structure, first excited state properties and charge distribution of a series of substituted stilbazolium cations in different media are theoretically investigated. First static hyperpolarizability (β₀) of considered compounds is studied by both finite-field and two-state model methods. In contrast to the recent theoretical studies, in present contribution the mutually consistent description of solvent polarity dependence of β₀ calculated by both employed approaches is achieved. It is shown that the ground-to-excited state intramolecular charge-transfer is significantly affected by the solvent that provides the hyperpolarizability variation. Taking into account both solvent polarity and substituent effect the peculiarities of β₀ behavior of stilbazolium derivatives are re-examined. The effect of molecular geometry on the calculated electronic excitation properties is investigated.