Table 5.
Coordination numbers (CN) and numbers of solute−water hydrogen bonds a.
| Oring/Hw | Sring/Hw | N/Hw | NH/Ow | −O/Hw | OH/Ow | =O/Hw | nHB(E) | |
|---|---|---|---|---|---|---|---|---|
| Oxazole | ||||||||
| 1a | --- b | 1.4 | 0.6 | 1.0 | 2.1(−14.6) | |||
| 1c | 0.3 c | 1.1 | 2.3 | 2.8(−16.7) | ||||
| 1d | 0.1 c | 0.6 | 1.9 | 2.1(−16.7 d) | ||||
| 3b | 0.4 | 1.3 | 0.8 e | 1.0 | 2.6(−14.6) | |||
| 3c | 0.1 f | 0.9 | 1.9 | 2.4(−16.7) | ||||
| Thiazole | ||||||||
| 2a | --- b | 1.3 g | 0.7 | 1.0 | 1.7(−14.6) | |||
| 2c | --- b | 1.0 | 2.1 | 2.7(−16.7) | ||||
| 2d | --- b | 1.0 | 1.9 | 2.2(−16.7 d) | ||||
| 4b | --- b | 1.6 | 0.9 | 1.0 | 2.7(−14.6) | |||
| 4c | --- b | 1.0 | 2.1 | 2.8(−14.6) | ||||
| Isoxazole | ||||||||
| 5a | 1.9 h | 2.0 i | 0.7 | 1.0 | 2.5(−14.6) | |||
| 5c | --- b | 1.0 | 2.4 | 3.2(−16.7) | ||||
| 7b | 1.1 | 1.7 | 0.8 | 1.0 | 2.2(−16.7) | |||
| 7c | 0.7 j | 1.1 | 1.5 | 2.2(−12.6 d) | ||||
| Isothiazole | ||||||||
| 6a | (0.2) k | 1.5 g | 0.9 | 1.0 | 2.8(−10.5) | |||
| 6c | --- b | 1.0 | 2.6 | 3.5(−16.7) | ||||
| 8b | --- b | 1.5 | 0.9 | 1.0 | 1.9(−16.7 d) | |||
| 8c | --- b | 0.4 l | 1.7 | 1.3(−16.7) |
a Coordination numbers were determined by the integration of the corresponding radial distribution functions up to their first minima generally at 250 ± 10 pm. Values in parentheses for nHB stand for the integration limits in kJ/mol for the solute−solvent pair-energy distribution functions; b No local minimum of rdf below 250 pm; c End of a rdf plateau at 225 pm; d End of a pedf plateau; e Rdf minimum at 230 pm; f Rdf minimum at 220 pm; g Rdf minimum at 265 pm; h Rdf minimum at 275 pm; i Rdf minimum at 270 pm; j End of a rdf plateau at 245 pm; k 0.2 Hw around the sulfur atom up to S…Hw = 250 pm without having a local rdf minimum up to this limit; l End of a rdf plateau at 240 pm.