Normal coordinate analysis of 2'-deoxythymidine and 2'-deoxyadenosine

The proposed valence force field allows us to reproduce the vibration modes of 2'-deoxythymidine and 2'-deoxyadenosine. The present calculations are based on the Wilson GF-method and a non-redundant set of symmetrical coordinates. The calculated wavenumbers have been compared to the available Raman and infrared peak positions observed in solid, amorphous or aqueous samples. Moreover, the results obtained with the present force field allow us to assign some of the characteristic vibration modes for the thymidine and adenosine residues involved in DNA double-helical chains.