Association constants (K, [M−1]) expressed as log K, effective molarities (EM), limiting NMR chemical shifts (δfree and δbound) and limiting complexation-induced changes in chemical shift (Δδ) measured by NMR titrations in toluene-d8 and chloroform-d at 298 Ka.
| Solvent | Complex | log K (M−1) | EM (mM) | 1H NMRb (ppm) | 19F NMRb (ppm) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1H (1) | 1H (2) | 19F (1) | 19F (2) | 19F (3) | ||||||||||||||
| δ free | δ bound | Δδ | δ free | δ bound | Δδ | δ free | δ bound | Δδ | δ free | δ bound | Δδ | δ free | δ bound | Δδ | ||||
| CDCl3 | D·A | 2.4 ± 0.1 | — | 5.7 | 11.8 | 6.1 | — | — | — | −61.3 | −63.0 | −1.7 | — | — | — | — | — | — |
| DD·AA | 3.9 ± 0.1 | 47 | 5.5 | 10.9 | 5.5 | 5.4 | 10.8 | 5.4 | −60.7 | −62.1 | −1.4 | −60.7 | −62.2 | −1.5 | — | — | — | |
| DDD·AAAc | 5.3 ± 0.1 | 66 | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | −60.7 | −62.0 | −1.3 | −60.7 | −62.2 | −1.5 | −61.0 | −62.4 | −1.4 | |
| Toluene | D·A | 3.6 ± 0.1 | — | 4.9 | 12.1 | 7.2 | — | — | — | −61.4 | −61.9 | −0.5 | — | — | — | — | — | — |
| DD·AAc | 6.1 ± 0.1 | 32 | n.d. | n.d. | n.d. | n.d. | n.d. | n.d. | −61.1 | −61.5 | −0.4 | −61.2 | −61.6 | −0.4 | — | — | — | |
a
Each titration was repeated twice, and the average value is reported with errors at the 95% confidence limit.
b
Data for the signals due to the OH and CF3 groups on the phenol recognition units.
c
Signals due to the OH protons were too broad to be detected. n.d. = not detected.