RADICAL-MOLECULE KINETICS IN PULSED UNIFORM SUPERSONIC FLOWS - TERMOLECULAR ASSOCIATION OF OH PLUS NO BETWEEN 90-K AND 220-K

The low-temperature dependence of the termolecular association reaction of OH with NO employing N-2 as the third body has been investigated using a new pulsed uniform supersonic expansion flow reactor. The absolute low-pressure reaction rate coefficient is reported for the temperature range 90-220 K. The temperature dependence of the rate coefficient for this reaction is found to be well fit by k = (7.0 +/- 2.0) x 10(-31)(T/300)(-2.6+/-0.3) cm(6) s(-1). The results agree with those obtained in the higher temperature regime and with RRKM predictions of the rate coefficient both validating the new technique and providing valuable information on the extended temperature dependence of this atmospherically relevant reaction.