From this study, two degradation species were detected, and it was determined that R-22 decomposed both by reduction and disproportionation reaction
According to (2a) and (2b), the disproportionation reaction
displayed by (2b) only happens under high hydrogen pressure.
Briefly, Mn(II) ion is firstly oxidized to the intermediate species of Mn(III) ion, which is thermodynamically unstable, and then disproportionation reaction
of Mn(III) ion occurs to generate Mn[O.sub.2] before Mn(III) ion is reduced to be Mn(II) ion.
At high temperature, hexatomic ring was cracked into free radical I and II (Scheme 1(a)), and then free radical I and II recurred disproportionation reaction
and generated 10-[(2-ethylhexyl)oxy]-10-oxodecanoate and 2-ethylhexene (peak 4, Scheme 1(b)).
, [Cu.sub.2]O should be also formed due to the disproportionation reaction
of Cu and [Cu.sup.2+]:
Practically, carbon formation could originate from the following four side reactions: methane decomposition/cracking reaction (1), Boudouard reaction or CO disproportionation reaction
(2), CO/H2 reduction reaction (3) and CO2 hydrogenation reaction (4).
One is the combination reaction and the other is the disproportionation reaction
. In general, radical polymerization proceeds with the abovementioned elementary reactions.
All the measurements were carried out at pH = 12, lower values were avoided to avoid the possible disproportionation reaction
of Mn(V) and Mn(VI) [5,9] and higher pH was avoided to slowdown the reaction rate.
Bhaskar, "Toluene Disproportionation Reaction
over HZSM-5 Zeolites.
2 shows the more common disproportionation reaction
leading to [S.sub.8][S(0)] and sulfite from the chemical literature (Cotton et al.
([double dagger]) The disproportionation reaction
derives its driving force from the formation of two newstrong bonds and from the fact that the [beta]-CH bonds in radicals are usually weak.
In alkaline solutions, a disproportionation reaction
occurs to hypochlorite resulting in the formation of chloride and chlorate (Mahan 1969).