Fig. 3. Energy plot of -CN bending out of the plane of the uridine ring.
The energies for various geometries of 6-CN-UMP with C6–C7 bent with respect to the plane of the pyrimidine moiety were computed using Gaussian 98, using the basis set 6-31+G*, at the DFT/B3-LYP theory level in gas phase. The potential energy scans (PES) were conducted at 15° angle steps. Solid circles trace the energy for bending the angle (centre of the aromatic ring) – C6 – C7 and open circles trace the energy for the angle C6 – C7 – N8.