Figure 13: Dependences of l o g 𝑘 Q (top) and log ( 1 / 𝑘 Q 1 / 𝑘 D i )) (bottom) on Δ 𝐺 E T for quenching of excited singlet state of thioxanthone by methylbenzenes (triangles) and methoxybenzenes (circles) in MeCN (according to the experimental data of Jacques et al. [39]). Best plots are shown for simulation of the experimental dependence by (3) ( 𝜆 = 0 . 1 and 0.5 eV, resp.) (dash lines) and by concatenated mechanism (16) (solid lines). Dotted line shows thermodynamic limit for ET. Experimental dependence of the exciplex emission frequencies, 𝜈 E x , on Δ 𝐺 E T in MeCN is shown in the middle panel.