Abstract
Neutron inelastic scattering (NIS) and ultraviolet resonance Raman scattering (RRS) experimental data have been obtained from purine nucleic base samples, i.e., adenine, C8-deuterated adenine, and a (N9, C6-amino)deuterated species. The two types of spectra have made it possible to carry out complete theoretical assignments of the vibrational modes of adenine and its derivatives. Normal mode wavenumbers as well as atomic displacements have been calculated by the Wilson GF method, using a valence force field and a non-redundant set of internal coordinates. In addition, the NIS intensities have been simulated by considering the fundamentals of the internal vibrational motions as well as their interaction with the lattice modes situated below 150 cm-1 in adenine and its deuterated species. The RRS intensities were simulated by using the bond-order changes induced by the electronic transition from the ground to the first excited state. It is clearly shown that the NIS spectra mainly arise from out-of-plane vibrations, while the ultraviolet RRS spectra are principally related to high-wavenumber in-plane stretching motions (above 1000 cm-1).
| Original language | English |
|---|---|
| Pages (from-to) | 1074-1084 |
| Number of pages | 11 |
| Journal | Journal of Physical Chemistry |
| Volume | 97 |
| Issue number | 5 |
| Publication status | Published - 4 Feb 1993 |
Keywords
- MOLECULAR-FORCE FIELDS
- MODES
- INTENSITIES
- STATE
- GEOMETRY