Diffusion coefficients, D (m2 s−1) and hydrodynamic radii, rH (Å) for 2 mM solutions at 298 K. Rotational radii, rRot (Å) calculated from molecular models and hypothetical diffusion coefficient Dprolate (m2 s−1) considering that the molecule has an ellipsoid shape.
| Ent. | Comp. (solv.) | D a/10−10 | r H b | r Rot | D prolate/10−10 |
|---|---|---|---|---|---|
| 1 | 3 (CDCl3) | 7.33c | 5.6 | 8.4 | 7.72 |
| 2 | 1 (CDCl3) | 5.76d | 7.1 | 7.6 | — |
| 3 | 2 (CDCl3) | 4.76e | 8.6 | 8.8 | — |
| 4 | 5 (CDCl3) | 3.68f,g | 11.1 | 17.8 (5·5) | 3.30 (5·5) |
| 10.9 (5) | 5.08 (5) | ||||
| 5 | 5 (DMSO-d6) | 0.98h | 11.2 | — | — |
a
Experimental error: ±2.0%.
b
Standard deviation: ±0.1 Å.
c
At 8.12 and 2.57 ppm.
d
At 4.64 and 3.77 ppm.
e
At 8.26 and 4.36 ppm.
f
At 2.58 ppm.
g
The diffusion coefficients at 8.63, 8.16, 8.00 and 3.26 ppm are in the range of 3.65–4.14 × 10−10 m2 s−1 (rH in the range of 9.8–11.2 Å).
h
Measured at 7.99 and 1.59 ppm. η (CHCl3, 298 K) = 0.536 × 10−3 kg s−1 m−1; η (DMSO, 298 K) = 1.991 × 10−3 kg s−1 m−1.37