UNUSUAL NARROW LINE FIR MODES OF CYTIDINE

We report the FIR (< 200 cm-1) optical absorption of crystalline powders of cytidine at cryogenic temperatures. The spectrum is unusual insofar as it can be described by 3 series of equally spaced very sharp lines. The data are interpreted as arising from rotations or librations of side groups (OH and NH2) of the molecule coupled with a very low frequency lattice vibration of the 4 molecules in the unit cell of the crystal. © 1979.