Kinetics of the NCS radical

The reaction kinetics of NCS radicals with several molecules was investigated for the first time, using laser-induced fluorescence spectroscopy to measure total rate constants and infrared absorption spectroscopy to probe possible reaction products. The NCS + NO reaction has a pressure-dependent total rate constant, with a low pressure (similar to 2 Torr) rate given by the expression k(NCS + NO) = (4.1 +/- 1.4) x 10(-15) exp[(1561 +/- 116)/T] cm(3) molecule(-1) s(-1) over the range 298-468 K. On the basis of the observed pressure dependence and product detection studies, this reaction is believed to be an association reaction, producing primarily NCSNO products. The NCS + NO2 reaction was pressure-independent, with a rate constant given by k(NCS + NO2) = (7.0 +/- 0.6) x 10(-12) exp[(579 +/- 39.4)/T] cm(3) molecule(-1) s(-1) over the range 298-620 K. No reaction of NCS with C2H2 or O-2 was detected, and upper limits of rate constants with these molecules were estimated at < 1.0 x 10(-14) cm(3) molecule-1 s(-1).