CIS-TRANS ISOMERIZATION BY A CHAIN MECHANISM IN LIQUID CIS-DECALIN IRRADIATED WITH HIGH-ENERGY RADIATION

Cis-trans isomerization occurs in liquid cis-decalin by a chain mechan ism, when irradiated with high-energy radiation. The cis-trans isomeri zation takes place as a result of the isomerization of the cis-9-decal yl radicals to trans-9-decalyl radicals, that subsequently form trans- decalin by a disproportionation reaction with other decalyl radicals a nd also by hydrogen abstraction from cis-decalin molecules. The latter process gives rise to formation of 9-decalyl radicals, so that a chai n reaction results at low dose rates. The kinetics of the process is a nalyzed. The specific rate of the cis-trans isomerization of the 9-dec alyl radical is found to be larger than 10(8) s(-1) in agreement with earlier estimates.