VIBRATIONAL-SPECTRUM OF URIDINE OBTAINED BY MEANS OF NONRESONANT-BACKGROUND-FREE CARS SPECTROSCOPY

The vibrational spectrum of uridine in aqueous solution is observed by means of the phase-mismatched CARS technique, in which the nonresonan t background is cancelled. The optimum condition for background suppre ssion is discussed. The skeletal vibrational modes of the base ring, C -H and N-H bending modes are resolved clearly. The vibrational modes o f the base ring are calculated using symmetry coordinates. The calcula ted values agree in principle with the experimental results and some d etailed characteristics of these modes are obtained.