NLOphoric studies in thiazole containing symmetrical push–pull fluorophores – Combined experimental and DFT approach

Abstract A series of donor–π–acceptor extended styryl chromophores having carbazole as electron donor with thiazole bridge and cyano group as the electron acceptors are investigated for nonlinear optical properties. The geometries of the extended styryls were optimized and electronic excitation properties were estimated using TD-DFT. The experimental solvatochromic shifts and density functional theory (DFT) computations are employed to understand the nonlinear optical properties of new generation push–pull fluorophores containing carbazole and thiazole cores. The solvatochromic polarizability values are calculated by two-level quantum mechanical model. Density Functional Theory is explored to determine the liner hyperpolarizability (α0), static first hyperpolarizability (β0) and second order hyperpolarizability (γ) for extended styryls. The calculation carried out by B3LYP method and 6-31G (d) basis set at ground state and excited state in different solvent polarity. The thiazole bridge in extended styryl enhances the nonlinear optical properties.