Solvatochromism of a D205 indoline dye at the interface of a small TiO2-anatase nanoparticle in acetonitrile: a combined molecular dynamics simulation and DFT calculation study

A combined molecular dynamics (MD) simulation and density functional theory (DFT) calculations were used to investigate the effect of acetonitrile (ACN) solution on absorption charge transfer in a D205 indoline dye at interface TiO2 nanoparticle. DFT carried out estimate equilibrium geometry small Ti30O62H4-anatase nanoparticle derive interaction parameters for bidentate binding TiO2. series configurations anchored Ti30O62H4 generated from MD simulations as input time-dependent (TD-DFT) calculations. We found that immersion D205-Ti30O62H4 composite system into polar ACN environment results conformational changes moiety, which are accompanied by solvatochromic redshift its long-wavelength band up 1900 cm-1. Our show HOMO LUMO energy level alignment suggests favourable driving force The MD/TD-DFT-estimated shift TiO2/ACN is good agreement with experiment, showing such computational approach enables reliable predictions optical properties other dye-TiO2 composites solution.