Table 3. Molecular geometry (Å, °) of N1-substituted uracil.
N denotes the number of CSD fragments used to determine the parameters. The recommended restraints are printed in bold.
| Parkinson (N = 46) | CSD (N = 180) | QM for U | QM for AU | |
|---|---|---|---|---|
| N1—C2 | 1.381 (9) | 1.381 (9) | 1.392 | 1.400 |
| C2—N3 | 1.373 (7) | 1.373 (8) | 1.378 | 1.376 |
| N3—C4 | 1.380 (9) | 1.381 (8) | 1.404 | 1.389 |
| C4—C5 | 1.431 (9) | 1.432 (8) | 1.450 | 1.451 |
| C5—C6 | 1.337 (9) | 1.337 (8) | 1.345 | 1.355 |
| C6—N1 | 1.375 (9) | 1.374 (8) | 1.371 | 1.371 |
| C2—O2 | 1.219 (9) | 1.219 (8) | 1.214 | 1.225 |
| C4—O4 | 1.232 (8) | 1.231 (8) | 1.215 | 1.236 |
| C6—N1—C2 | 121.0 (6) | 121.1 (5) | 121.27 | 121.07 |
| N1—C2—N3 | 114.9 (6) | 114.9 (6) | 114.26 | 115.27 |
| C2—N3—C4 | 127.0 (6) | 127.0 (5) | 128.25 | 126.84 |
| N3—C4—C5 | 114.6 (6) | 114.5 (6) | 112.95 | 114.71 |
| C4—C5—C6 | 119.7 (6) | 119.7 (6) | 119.89 | 119.31 |
| C5—C6—N1 | 122.7 (5) | 122.7 (5) | 123.38 | 122.80 |
| O2—C2—N1 | 122.8 (7) | 122.8 (7) | 122.30 | 121.28 |
| O2—C2—N3 | 122.2 (7) | 122.3 (6) | 123.44 | 123.46 |
| O4—C4—C5 | 125.9 (6) | 126.0 (7) | 126.60 | 124.62 |
| O4—C4—N3 | 119.4 (7) | 119.5 (7) | 120.45 | 120.67 |
| RMSD versus QM for U (d/a) | 0.0109/1.090 | |||