Novel nonequilibrium solvation theory for calculating the solvatochromic Stokes shift by State-specific TD-DFT

Abstract

The expression of solvatochromic Stokes shift was deduced using self-consistent SS-PCM/TD-DFT method based on the novel nonequilibrium solvation theory. As a typical case, a fluorescent dye of 2,5-bis (6-amine-benzoxazol-2-yl) thiophene (BBTA) was investigated. The obtained absorption and emission energies as well as Stokes shift for BBTA in DMSO are in line with available experimental findings. The contributions to the solvatochromic shift are discussed and the electrostatic components are found to be crucial for the electronic absorption and emission spectra in polar solvents. We hope this work can shed new light on the synthesis and application of fluorescent organic dyes.