Formation of the iodine monoxide radical from gas-phase reactions of iodoalkyl radicals with molecular oxygen

Formation of the iodine monoxide radical (IO) was observed during the reaction of iodoalkyl radicals (RCHI) or cyclo-C6H10I radical with O2 at 298 K, where R stands for CnH2n+1 (n = 0-3). Figure shows a typical time profile of IO produced from the reaction of CH3CHI with O2 in 20 Torr N2 diluent at 298 K. The inset shows the absorption spectrum of IO at 1 ms after 355 nm photolysis of the CH3CH2I/Cl2/O2/N2 mixture (20 Torr total pressure at 298 K).