FAR-INFRARED STUDY OF THE VIBRATIONAL-MODES OF 5'-GMP GELS AND CRYSTALS OF NA+ AND K+

Five Far-Infrared (50 - 600 cm-1) spectra are presented: the sodium an d potassium salts of 5' Guanosine Monophosphate (GMP), each salt in bo th the gel and crystal conformations, and poly(rG). Measurements were performed at a sample temperature of 10 K under vacuum with a liquid H e-cooled bolometer. The spectra were fit with Lorentzians and assignme nts are suggested. There are noteworthy differences in oscillator stre ngths and frequencies of the bands between all spectra. We report the tentative observation of a 100 cm-1 mode which is in the neighborhood of a mode observed by Raman spectroscopy in solution (1) and dried gel s (2).