Table 2 Association constants (Ka, M−1) and thermodynamic parameters (ΔHo and −TΔSo, kJ mol−1) of naphthotubes 5a and 5b with G1–G3 in phosphate buffer (50 mM, pH = 7.4 or 12, H2O) at 298 K as determined by ITC titrationsa.
Guest | Host | pH 7.4 | pH 12 | ||||
|---|---|---|---|---|---|---|---|
Ka | ΔHo | −TΔSo | Ka | ΔHo | −TΔSo | ||
G1 | 5a | (4.5 ± 0.2) × 103 | −35 ± 4 | 14 ± 4 | (2.5 ± 0.2) × 102 | −10.3 ± 0.1 | −3.3 ± 0.2 |
5b | (4.4 ± 0.1) × 103 | −18 ± 1 | −2 ± 1 | (5.0 ± 0.3) × 102 | −15 ± 2 | −1 ± 2 | |
G2 | 5a | (8.4 ± 0.1) × 104 | −42.4 ± 0.5 | 14.3 ± 0.5 | (2.4 ± 0.4) × 103 | −22 ± 2 | 2 ± 2 |
5b | (3.7 ± 0.1) × 105 | −36 ± 1 | 4.2 ± 0.9 | (1.5 ± 0.2) × 104 | −30 ± 3 | 7 ± 3 | |
G3 | 5a | (2.0 ± 0.2) × 104 | −29 ± 2 | 5 ± 2 | (5.8 ± 0.3) × 102 | −20 ± 2 | 5 ± 2 |
5b | (9.4 ± 0.3) × 104 | −28 ± 2 | −1 ± 2 | (1.7 ± 0.1) × 103 | −19 ± 1 | 1 ± 1 | |
