Lb. Herbert et al., RATE CONSTANTS FOR THE RELAXATION OF CH(X(2)PI,NU=1) BY CO AND N-2 ATTEMPERATURES FROM 23 TO 584 K, Journal of physical chemistry, 100(36), 1996, pp. 14928-14935
Rate constants have been determined for the collisional relaxation of
CH(X(2) Pi,nu = 1) by CO and N-2 over a wide range of temperatures. Ex
periments between 584 and 86 K have been performed in heated and cryog
enically cooled cells, and rate constants from 295 to 23 K have been m
easured in a CRESU (cinetique de reaction en ecoulement supersonique u
niforme) apparatus. In both series of experiments, pulsed laser photol
ysis was employed to generate CH radicals and the laser-induced fluore
scence technique was used to observe the rate of removal of CH(nu = 1)
. Vibrational relaxation is rapid, k(298) = 9.7 x 10(-11) cm(3) molecu
le(-1) s(-1) for CO and k(298) = 3.1 x 10(-11) cm(3) molecule(-1) s(-1
) for N-2, and the dependence of the rate constants on temperature is
quite slight but complex. The results suggest that relaxation occurs v
ia strongly bound complexes, and the implications of the results for t
he interpretation of the reactions between CH radicals and CO and N-2
are discussed.