The Mercury Photosensitized Reactions of Methyl Alcohol

Abstract

The mercury photosensitized reactions of methyl alcohol have been investigated at pressures of 30 and 100 mm Hg and over a temperature range from 25° to 500°C. Below 400°C the products are almost entirely hydrogen and ethylene glycol and small amounts of carbon monoxide, formaldehyde and methane. It has been established that the primary step in the reaction mechanism is $\mathrm{Hg}{(}^3{\mathrm{P}}_1\mathrm{)+}{\mathrm{CH}}_3\mathrm{OH}\to {\mathrm{CH}}_2\mathrm{OH}+\mathrm{H}+\mathrm{Hg}{(}^1{\mathrm{S}}_0)$ . There is considerable supporting evidence that the alternative split into H+CH₃O does not occur. Above 400°C the rates of production of CH₂O and CO become significant and increase with rising temperature which has been explained by the fact that the decomposition of the CH₂OH radical is taking place. An activation energy of 29 kcal. has been obtained for this decomposition reaction.