IODINE AS A RADICAL SCAVENGER IN THE RADIOLYSIS OF CYCLOPENTANE

Scavenging techniques with iodine in the concentration range of 0.1 to 30 mM were used to elucidate the radical yields in the gamma-radiolys is of cyclopentane. In solutions below about 1 mM iodine reacts solely with alkyl radicals in the bulk of the medium. However, above this co ncentration the scavenging of thermal hydrogen atoms becomes significa nt and virtually all of the hydrogen atoms are scavenged at an iodine concentration of 30 mM. High concentrations of iodine are also found t o reduce the cyclopentene yield, probably by reaction with ionic speci es produced as intermediates in cyclopentane radiolysis. At low iodine concentrations the yield of the main scavenging product, cyclopentyl iodide, and thereby the yield of the scavenged cyclopentyl radicals th at escape the spur into the bulk medium was found to be 4.0 radicals/1 00 eV. The total cyclopentyl radical yield derived from the observed k (d)/k(c) ratio and the bicyclopentyl yield is estimated to be 4.9 radi cals/100 eV.