| Isotope effects were found experimentally in four fluorescent dyes: cresyl violet, darrow red, oxazine 4 and oxazine 170. To understand the underlying mechanism responsible for these effects, we searched for a first-principles approach to describe the electronic structure of these dye molecules. We found that TD-DFT methods using TPSS and B3LYP functionals with the 6-31G* basis set performed well in describing emission spectra of these dyes. This provided us with a solid base for further investigation of the isotope effect in these compounds. |
