Solvation effects and inhomogeneous broadening in optical spectra of phenol blue

Electronic and vibrational spectra of phenol blue dissolved in a few solven ts are carefully analyzed on the basis of a simple theoretical model accoun ting for electron-molecular vibration coupling and for solvation. Nonresona nt Raman and electronic absorption spectra measured in a series of solvents with similar refractive index and increasing dielectric constant are the b asis to extract a reliable set of microscopic parameters. On the basis of t hese parameters, we reproduce the large and impressive inhomogeneous broade ning effects observed in resonant Raman spectra collected in polar solvents . Solvation effects on the first hyperpolarizability are also discussed.