where 𝐸 R is the activation energy, 𝑘 S is the Boltzmann constant, 𝐴 is the frequency factor, 𝛥𝐻 ‡ is the activation enthalpy, 𝛥𝑆 ‡ is the activation entropy and κ is the transmission coefficient. 𝐸 R = 0.26 eV is determined from the Arrhenius plot (Figure ). This activation is associated with the reorganization required for the molecular framework change between the anthracene units, as mentioned above. We also performed the Eyring plot in Figure to determine the activation enthalpy (𝛥𝐻 ‡ = 0.23 eV ) and the activation entropy (𝛥𝑆 ‡ = 0.45 meV K -1 ). ) and (c)