Abstract:
Rates of H2 formation have been determined for the thermal decomposition
of isopropyl peroxide at l30o-l50oC in toluene and methanol and at l400C in
isopropyl alcohol and water. Product studies have been carried out at l400C
in these solvents.
The decomposition of isopropyl peroxide was shown to be unimolecular
with energies of activation in toluene, and methanol of 39.1, 23.08 Kcal/mole
respectively.
It has been shown that the rates of H2 formation in decomposition of
isopropyl peroxide are solvent dependent and that the ~ vs "'2';' values
(parameters for solvent polarity) givesastraight line. Mechanisms for
hydrogen production are discussed which satisfactorily explain the
stabilization of the six-centered transition state by the solvent. One
possibility is that of conformation stabilization by solvent and the other,
a transition state with sufficient ionic character to be stabilized by a
polar solvent.
Rates of thermal decomposition of 1,2-dioxane in tert-butylbenzene
at l40o-l70oC have been determined. The activation energy was found to
be 33.4 Kcal/mole. This lower activation energy, compared to that for
the decomposition of isopropyl peroxide in toluene (39.1 Kcal/mole) has
been explained in terms of ring strain. Decomposition of 1,2 dioxane in
MeOH does not follow a first order reaction.
Several mechanisms have been suggested for the products observed
for decomposition of 1;2-dioxane in toluene and methanol.
