Rotational diffusion of oxazine 17 in hydrogen-containing and deuterated alcohols

The rotational relaxation time and its spectral dependence were determined for oxazine 17 in hydrogen-containing alcohols and it was found that the governing factor was an intermolecular hydrogen bond with the solvent. A strong reduction in the strength of this intermolecular interaction in deuterated alcohols was accompanied by a short-wavelength shift of the fluorescence spectrum and by an increase in its quantum efficiency.