Solvation effects and inhomogeneous broadening in optical spectra of phenol blue

Electronic and vibrational spectra of phenol blue dissolved in a few solvents are carefully analyzed on the basis of a simple theoretical model accounting for electron−molecular vibration coupling and for solvation. Nonresonant Raman and electronic absorption spectra measured in a series of solvents with similar refractive index and increasing dielectric constant are the basis to extract a reliable set of microscopic parameters. On the basis of these parameters, we reproduce the large and impressive inhomogeneous broadening effects observed in resonant Raman spectra collected in polar solvents. Solvation effects on the first hyperpolarizability are also discussed.