Solvation of C2H5OH, CH3CHO, and CH3COCH3 molecules on D2O and CD3OD–ice surfaces

TOF-SIMS is used to characterize the solvation of C2H5OH, CH3COCH3, and CH3CHO molecules on the D2O and CD3OD layers at cryogenic temperatures (15–200 K). The C2H5OH and CH3COCH3 molecules are basically not incorporated in the D2O layer up to the evaporation temperature (170 K), whereas the CH3CHO molecule disappears from the surface above the phase transition temperature of the D2O ice (140 K). All of these molecules are incorporated in the CD3OD layer above 100–120 K. These results suggest that the alkyl group tends to be excluded from the D2O layer but attractive interactions between the alkyl groups promote solvation of these molecules in the CD3OD layer. The yields of the Hþ(C2H5OH)n ions sputtered from the pure C2H5OH layer decreases with increasing temperature since the hydrogen-bond defects are annealed.