Figure 4.

Influence of a competitor on the LLS lifetime of a weak ligand. The LLS lifetimes T_LLS^obs of the pair of aromatic protons of the bromothiophene spin-pair label as a function of the dissociation constant of a competing stronger ligand, calculated using Equations (6) and (7). The parameters of the weak ligand BT-GGR were obtained from the fit of the data in Figure 3: K_D=0.2 mm, T_LLS^bound=0.1 s, T_LLS^free=11 s, [L]₀=0.5 mm, [P]₀=25 μm, and [L^s]₀=50 μm. The three points correspond to T_LLS^obs in the presence of myricetin (K_D^strong=3 μm, •), apigenin (K_D^strong=39 μm, ▪) and in the absence of any competitor (★) calculated for these conditions.