The combination of methyl radicals: photolysis of acetone at low pressures

The kinetics of the photo-decomposition of acetone at low pressures (20 to 0$\cdot $2 mm) are consistent with the participation of a third body in the recombination of methyl radicals. Various added gases increase the relative rate of formation of ethane; approximate values, relative to acetone, are given for their efficiencies in deactivating excited ethane molecules by collision. The rate of spontaneous redissociation of the activated complex is less than 6 $\times $ 10$^{7}$ s$^{-1}$ at 520 degrees K, and increases with temperature.