The activation energies of reactions involving conjugated systems

Structure-reactivity relationship in pyrolysis of plastics: A comparison with natural polymers

“…The existence of a commonly reported trend is confirmed, but the correlation (R 2 = 0.25) is weak for this limited data set. Formation of first radicals by initiation reactions is therefore not necessarily the rate-determining step; and pyrolysis reactions not only include both atom and electron transfer, as well as polar effects [95], but also reflect important bond-strength and structural differences between reactants and products, including kinetically important transition-state stabilization due to aromatic resonance [96][97][98]. And its implications are instructive, especially when considering the deviation of the slope (0.25 ± 0.20) from the value of 1.0 for homolytic dissociation [88,99], which emphasizes the fundamental differences existing within pyrolysis modes (e.g., ionic and non-ionic modes) of polymers.…”

Conversion of Hydrocarbons into Butadiene.

“…The endothermic heat of decomposition of 1-vinylcyclohexene-3 is 23 kcal. per converted gram-mole (48). Dehydrogenation of ethylcyclohexane or ethylcyclohexene is also endothermic.…”

A Critical Assessment of Classical and Semi-Classical Models for Electron Transfer Reactions in Solution

“…a reaction coordinate inspired by the "diabatic reaction path" proposed by Evans and Polanyi [118]. This path is constructed by taking two intersecting potential-energy surfaces and then obtaining the cross-section through the two surfaces which leads to the lowest point of intersection between them [119]. The resonance energy between the initial and final states is treated as an additional factor.…”