Table 1.
Binding affinity, pKa, and Log P values for each metalloinsertor
| Metalloinsertor | Binding Constant (× 106 M−1)a | pKa (2+ to 1+) | Log P |
|---|---|---|---|
| Δ-[Rh(phen)(chrysi)(PPO)]2+ | 6.6 | – | – |
| Λ-[Rh(phen)(chrysi)(PPO)]2+ | 9.2 | – | – |
| rac-[Rh(phen)(chrysi)(PPO)]2+ | 5.5b | 8.3 ± 0.3a | 1.4 ± 0.1 |
| rac-[Rh(bpy)(chrysi)(PPO)]2+ | 7.2 | 8.9 ± 0.1 | 0.68 ± 0.07 |
| rac-[Rh(HDPA)(chrysi)(PPO)]2+ | 3.0 | 9.1 ± 0.1 | 0.69 ± 0.08 |
| rac-[Rh(4,7-DMP)(chrysi)(PPO)]2+ | 1.5 | 9.1 ± 0.1 | 1.1 ± 0.1 |
| rac-Rh[(5,6-DMP)(chrysi)(PPO)]2+ | 2.3 | 9.0 ± 0.3 | 0.71 ± 0.01 |
| rac-[Rh(DIP)(chrysi)(PPO)]2+ | 1.6 | 8.1 ± 0.1 | > 2.0c |
a
binding affinities measured using the DNA hairpin 5′-GGCAGGCATGGCTTTTTGCCATCCCTGCC-3′ (underline denotes mismatch) in 100 mM NaCl, 20 mM NaPi, pH 7.1 buffer. Competition titrations were performed against the photocleaving metalloinsertor [Rh(bpy)2(chrysi)]Cl3.
b
Values from reference 19
c
The change in absorbance in the [Rh(DIP)(chrysi)(PPO)]2+-containing 1-octanol phase before and after equilibration with the aqueous phase was too small to accurately and consistently measure.