Pyrrole-thiazole based push-pull chromophores: An experimental and theoretical approach to structural, spectroscopic and NLO properties of the novel styryl dyes

Novel push-pull fluorophores constituted by two donors (substituted pyrrole and morpholine) linked to acceptor through thiazole electron spacer have been synthesized. The fluorophores are investigated for linear and non-linear optical properties by UV-VIS absorption and fluorescence spectroscopies, and by means of TD-DFT (B3LYP/6-31G(d)) method, with the aim of elucidating the ability of the morpholine/ pyrrole-donor-thiazole-spacer based D-pi-A fluorophores as organic NLO materials. The bond length alternation and generalized Mulliken-Hush (GMH) analysis is performed to understand the involvement of the donor in effective transfer of the charge to acceptor. Values of first-order hyperpolarizabilitiet (beta(CT) or or beta(0)), obtained by the solvatochromic method (Lippert Mataga model), and the transition dipole moments (mu(eg)) used to characterize and evaluate the non-linear optical performances of the D-pi-A fluorophores in various microenvironments. The D-pi-A fluorophores possess good values of beta(CT) or beta(0) in different organic solvents and hold high thermal stabilities therefore can be used as potential organic NLO materials. (C) 2016 Elsevier B.V. All rights reserved.