Investigation of Nucleosides Molecular Structure

The investigations of nucleoside molecular structures are of fundamental interest for molecular biology. Up to the present the main experimental information about their structure was obtained from the data for the crystals and solutions [1]. But the intermolecular interaction strongly influences on the conformational and tautomeric equilibrium. And their result can not be compared with quantum chemical calculations. Therefore it is very interesting to obtain an information about nucleoside structure in the isolated conditions. Owing to weak intermolecular interactions in the inert matrices and their optic transparent, matrix isolation spectroscopy is very useful tool for such investigations. The main problem is low thermostability of nucleosides and consequently it is difficult to obtain the molecular beam. Previously we solved this problem for uridine and thymidine [2]. In this work we compare the results of our calculation method PM3 with the data obtained from FTIR matrix isolation spectroscopy.