Figure 8: 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 (1) and triplet (2) states of biacetyl by alkenes in MeCN (according to the experimental data of Gersdrof et al. [33]). Best plots are shown for simulation of the experimental dependence by (3) ( 𝜆 = 0 . 9  eV) (dash line) and by concatenated mechanism (16) (solid line). Dotted line shows thermodynamic limit for ET.