Knowledge Bank

Band system in the region 852 $-$ 880 nm and bands 670 and 846 nm over pressures 0.1 $-$ 1 atm in the flames of mixtures of hydrogen with oxygen and air has been detected. The system is assigned to overtone transitions of H$2$O$2$ (3$\nu 1+\sigma$) correspondingly arising from the reaction of HO$2+$HO$2-$H$2$OO$_2 +$33.5kcal/mole.Thebands670and846nmareassignedtoovertonetransitionsofHO$_2$ radical (4$\nu 1+\sigma$) and (3$\nu 1+\sigma$) correspondingly arising from the reaction of H$+$O$2$($+$M)$-$HO$2$($+$M) $+$ 44 kcal/mole. By this means the extent of energy of these elementary processes is located in vibrational degrees of freedom of products. It has been detected that HO$2$ radicals occur originally in overtone-excited states in combustion both of hydrogen and deuterium in the presence of small additives of propylene as an inhibitor.