Table 1.
Complex | Ancillary ligand | KB(CC)/M-1 | KB (AC)/M-1 |
---|---|---|---|
Rh(NH3)4chrysi3+ | NH3 | 1.0 × 108 | 3.4 × 106 |
Rh(bpy)2chrysi3+ | 3.4 × 107 | 2.2 × 106 | |
Rh(HDPA)2chrysi3+ | 2.0 × 107 | 2.6 × 106 | |
Rh(phen)2chrysi3+ | 3.2 × 106 | 1.4 × 106 | |
Rh(DIP)2chrysi3+ | 9.1 × 104 | < 104 |
Uncertainties are estimated to be 10%. Binding constants are determined from photocleavage or binding competition titrations using a DNA hairpin with the sequence 5′-GGCAGGXATGGCTTTTTGCCATCCCTGCC-3′ (X = C or A, underline denotes the mismatch). Samples were irradiated with a solar simulator (340–440 nm) at 37 °C in 50 mM NaCl, 10 mM NaPi, pH 7.1, as described in the Experimental Procedures.
For the polypyridyl complexes, values are given for racemic mixtures.