Kinetics of reactions involving CN emission IV. Study of the reactions of CN by electronic absorption spectroscopy

The kinetics of the reaction between oxygen atoms and cyanogen have been studied in a capacity flow reactor at temperatures between 570 and 687 °K. The concentration of CN radicals was measured by electronic absorption spectroscopy. This work confirms the previously proposed mechanism (part II). The initial step has a rate constant of k1 = 2∙5 (± 0∙3) x 1013exp ( – 11000±2000/RT) cm3 mole–1 s–1. CN radicals are removed mainly by reactions (4) and (2) for which k4 = 6∙3 (±3∙5) x 1013exp (–2400±700/RT) cm3 mole–1s–1 and k2 = 4∙4 (±2∙0) x 1012 cm3 mole–1s–1. CN+O = CO+N, (4) CN+O2 = NCO+O. (2) The rates of reaction of CN with NO and NH3 were also measured; for CH4 and H2 limiting values were obtained.