Table 2. Pseudorotation Phases Pθ, Pucker Amplitudes Ar, and Relative Energies ΔE of Minima (MIN) and Transition States (TS) of Abasic Nucleosides, dH and rHa.
| MIN1 |
MIN2 |
TS1 |
TS2 |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pθ (deg) | Ar (deg) | ΔE (kcal/mol) | Pθ (deg) | Ar (deg) | ΔE (kcal/mol) | Pθ (deg) | Ar (deg) | ΔE (kcal/mol) | Pθ (deg) | Ar (deg) | ΔE (kcal/mol) | ||
| dH | CBS-QB3b | 6.3 | 42.0 | 2.5 | 156.2 | 40.5 | 0.0 | 77.8 | 42.6 | 2.9 | 317.0 | 42.0 | 3.0 |
| CBS-QB3 | 336.4 | 38.4 | 2.9 | 157.8 | 39.8 | 0.0 | 78.2 | 39.4 | 3.0 | 263.4 | 36.8 | 1.9 | |
| MP2c | 6.3 | 42.0 | 2.4 | 156.2 | 40.5 | 0.0 | 77.8 | 42.6 | 2.8 | 317.0 | 42.0 | 2.9 | |
| MP2tzd | 2.5 | 42.1 | 2.6 | 155.6 | 40.5 | 0.0 | 76.6 | 42.8 | 3.0 | 319.0 | 42.2 | 2.9 | |
| B3LYPe | 358.4 | 38.6 | 1.4 | 153.1 | 38.3 | 0.0 | 58.9 | 38.8 | 1.6 | 293.2 | 37.5 | 1.8 | |
| rH | CBS-QB3b | 357.4 | 43.2 | 1.5 | 150.8 | 43.2 | 0.0 | 74.2 | 42.1 | 3.6 | 278.9 | 32.7 | 5.1 |
| CBS-QB3 | 355.1 | 39.9 | 1.6 | 153.0 | 41.3 | 0.0 | 68.2 | 38.7 | 3.6 | 274.8 | 30.9 | 5.1 | |
| MP2c | 357.4 | 43.2 | 1.4 | 150.8 | 43.2 | 0.0 | 74.2 | 42.1 | 3.5 | 278.9 | 32.7 | 4.9 | |
| MP2tzd | 356.4 | 43.1 | 1.5 | 150.5 | 43.2 | 0.0 | 73.2 | 42.2 | 3.4 | 280.1 | 32.8 | 4.7 | |
| B3LYPe | 359.0 | 39.9 | 1.2 | 149.3 | 40.9 | 0.0 | 64.1 | 38.2 | 2.3 | 276.6 | 30.0 | 4.0 | |
a
Nucleobases in the dH and rH are replaced by hydrogen atoms.
b
CBS-QB3//MP2/6-31++G(d,p).
c
MP2/6-311++G(3df,2p)//MP2/6-31++G(d,p).
d
MP2/cc-pVTZ//MP2/6-31+G(d).
e
B3LYP/6-311++G(3df,2p)//B3LYP/6-31++G(d,p).