Abstract:
Re~tes artd pJ~oducts of tllerma]. d,ecom.position of
sec-butyl peroxide at 110 - 150°C i.n four solvents h,ave
been determined.
The d,ecompos i tion vJas sb.o\'\Tn to be tlnlmolecl.llar wi tho
energies of activation in toluene, benzene, and cyclohexane of
36 .7-+ 1.0, 33.2 +- 1..0, 33.t~) +.. 1.0 I'(:cal/mol respectively.
The activation energy of thermal decomposition for the
d,et.1terated peroxide was found to be 37.2 4:- 1.0 KC8:1/1TIol in
toluene.
A.bo1J.t 70 - 80/~ ol~ tJJ.e' pl~od.1..1CtS could, be explained by
kn01rJ11 reactions of free allcoxy raclicals J and very littJ...e, i.f
allY, disPl"Opox~tiol'lation of tll10 sec-butoxy radica.ls in t116
solvent cage could be detected.
The oth,er 20 - 30% of the peroxide yielded H2 and
metb.:'ll etb..yl 1{etol1e. Tl1.e yield. o:f H2 "'lIas unafJ:'ected by the
nature or the viscosity of the solvent, but H2 was not formed
when s-t1U202 lrJaS phctolyzed. in tolttene at 35°C nor 'tl!Jrl.en the
peroxide 1;'JaS tl1.ermally o..ecoJnposed. in the gas p11ase.
~pC-Dideutero-~-butYlperoxide was prepared
and decomposed in toluene at 110 - 150°C. The yield of D2
was about ·•e1ne same 248 the yield. of I{2 from s-Bu202, bU.t th.e
rate of decomposition (at 135°C) 1iJas only 1/1.55 as fast.
Ivlecl1.anisms fOl') J:1ydrogen produ.ction are discussed,
but none satisfactorily explains all the evidence.
