Raman and infrared (IR) spectra were recorded for crystalline cytidine samp
les at 298, 160, 75 and 10 K. Data were taken over the spectral range 20-40
00 cm(-1). The wavenumbers of most vibrational modes were found to increase
as the temperature was lowered, but several peaks near 3000 cm(-1) showed
the opposite trend. A number of peaks split into multiplets at low temperat
ure. No evidence was found of any structural phase transitions in this temp
erature range. Plausible assignments of all main observed features are sugg
ested. Copyright (C) 2001 John Wiley & Sons, Ltd.