Raman spectroscopy of glycerol/D₂O solutions

Raman spectra of neat glycerol, neat D₂O, and glycerol/D₂O solutions with glycerol mole fractions (X_G) of 0.00, 0.02, 0.12 and 0.32 and 1.00 are presented. Vibrational assignments are discussed for the bands observed in the 1000-1600 and 2000-3700 cm^-1 spectral regions. Upon dilution of neat glycerol with D₂O, glycerol hydrogen-bonds with D₂O through its oxygen atoms as hydrogen-bond acceptors. With progressive glycerol dilution, D₂O breaks the dimers and higher oligomers present in neat glycerol to form glycerol monomers. D₂O molecules in the X_G 0.02 solution are in an environment similar to that of neat D₂O due to minimal perturbation of the D₂O network. The absence of bands due to weakly hydrogen-bonded D₂O in the X_G 0.12 solution suggests that most D₂O are more strongly hydrogen-bonded than in neat D₂O as would occur in D₂O clusters. D₂O in X_G 0.32 solutions are in a unique environment in that they lose their hydrogen-bonding network completely, mixing into the solution as monomers.