Blue shift of the isolated CD stretching band of CH2DOH in water induced by changes in the hydrogen-bonding pattern.
The wavenumber shift in the CD stretching (ν(CD)) band of the monodeuterated methanol (CH(2)DOH) has been monitored in water-methanol mixtures. For the pure liquid, two dominant bands are observed at 2148 and 2176 cm(-1) in the ν(CD) region. The matrix isolation technique and spectral simulation based on quantum chemical calculations have revealed that these two bands are categorized into the C(1) mode and originate from methanol molecules participating in different hydrogen(H)-bonding patterns. The simulation results for methanol clusters have suggested that the 2148 cm(-1) band is concerned with the end-donor species in the H-bonding network. The relative intensity of the band near 2148 cm(-1) decreases with increasing water concentration, indicating that the population of the end-donor species decreases by the addition of water. This spectral change causes the blue shift in the mean center of the ν(CD) band of CH(2)DOH in water.
Graduate School of Science, Hiroshima University, Kagami-yama 1-3-1, Higashi-hiroshima 739-8526, Japan.
Takafumi
T
Shimoaka
Yukiteru
Y
Katsumoto