Quantum-chemical study of structure and spectral properties of triphenylamine-rhodanine dye 2-(5-(4-(diphenylamine)benzylidene)-4-oxo-2-thioxothiazolidine-3-yl) acetic acid

The structure and optical properties of triphenylamine-rhodanine dye 2-(5-(4-(diphenylamine)benzylidene)-4-oxo-2-thioxothiazolidine-3-yl) acetic acid, which is used as a sensitizer for nanocrystalline TiO 2 solar cells, are studied based on the density functional theory. The nature of the absorption of this dye in the visible and near UV regions is discussed within the time-dependent density functional theory (TDDFT). The calculations of the vertical excitation energies of the dye molecule taking into account the effect of solvent reveal a strong positive solvatochromic effect compared to the calculations in the vacuum approximation. The IR absorption bands of this dye in the region of 600–1850 cm −1 are completely interpreted.