Raman spectral changes of alcoholic zinc chloride solutions from liquid state to glassy state

Raman spectral changes associated with vitrification were measured for ZnCl₂·4OROH solutions (ROH=methanol, ethanol and 1-propanol). Solvated ZnCl₂ is the only major Zn-species in these solutions at room temperature while the dominant Zn-species stabilized in the glassy alcoholic solutions are ZnCl ₃ ^– , ZnCl ₄ ^2– and Zn(MeOH)₆]²⁺ for the methanol solution, ZnCl₂ and ZnCl ₃ ^– for the ethanol solution and ZnCl₂ for the 1-propanol solution. Together with Raman data for aqueous ZnCl₂ solutions, the differences in the dominant Zn-species in the glassy alcoholic solutions are discussed in terms of the dielectric constants of solvents (water and alcohols).