119effective scavengers at concentrations sufficiently low not to interfere appreciably with hot processes. We conclude that IBr and IC1 scavenge hot hydrogen systems with an efficiency comparable to that of I 2 and Br 2 . They are preferable to Br 2 because of their lower reactivity with non-radicals, and to I 2 because of their higher vapor pressure. In scavenging alkyl radicals they have the additional advantage of yielding alkyl chlorides and bromides rather than the higher boiling iodides. SummaryThe radioactive products formed in the activation of iodobenzene, iodosobenzene, iodoxybenzene and diphenyliodonium iodide have been analyzed. The radiochemical yield of zero valent iodine was 13-25%, and iodine was not an effective scavenger for hot iodine atoms. The anionic yield was only appreciable for iodoso-and iodoxy-benzene, and was largely iodide and iodate. The main labeled product in all cases was iodobenzene. Some labeled iodosobenzene was formed from iodoxybenzene. These products resulted from recombination reactions.

Die bei der Aktivierung von Jodbenzol, Jodosobenzol, Jodoxybenzol und Diphenyljodoniumjodid gebildeten radioaktiven Produkte sind untersucht worden.