813987.fig.0017
Figure 17: Experimental apparent activation free energy (blue □) and activation enthalpy (red ○) for quenching of aromatic compounds by various quenchers [6671]. Free energies of transient exciplex formation (magenta ▲) are calculated according to (10) (for 𝜏 0 = 1  ns); the entropy of transient exciplex formation (green ♦) 𝑇 Δ 𝑆 E x = Δ 𝐻 E x Δ 𝐺 E x (assuming Δ 𝐻 E x Δ 𝐻 A p p ). Simulated curves are: ( 1 ) Δ 𝐺 for Marcus mechanism ((2), 𝜆 = 0 . 6  eV) and ( 2 ) Δ 𝐺 E x for transient exciplex mechanism ((15), 𝑎 = 0 . 1 3 , 𝑏 = 0 . 0 7 , 𝑐 = 0 . 1 4  eV); ( 3 ) Δ 𝐻 A p p = 0 . 1 2 Δ 𝐺 E T / 2 ( ( Δ 𝐺 E T / 2 ) 2 + 0 . 1 4 2 ) 1 / 2 .