36th DPS Meeting, 8-12 November 2004 Session 20 Titan
[Previous] | [Session 20] | [Next]  [20.08] Atmospheric
Chemistry of Titan: Total Rate Constant for the Reaction of CH3
+ C2H5 + M arrow C3H8 + M at Low Temperatures and Pressures  R.
J. Cody, A. S. Pimentel, W. A. Payne (NASA / GSFC), F. L.
Nesbitt (Catholic University of America)  The recent infrared
observation by Roe et al (2003, ApJ 597, L65) has unambiguously
detected the hydrocarbon propane in the stratosphere of Titan.
Photochemical models predict that the reaction CH3 + C2H5 + M
arrow C3H8 + M (1) is the source of C3H8 in the atmospheres of
Titan and the Outer Planets and is expected to be one of the
important loss processes for C2H5. There have been four direct
studies of the rate constant for Reaction 1 but none at the
lower temperatures and pressures needed for the atmospheric
modeling studies. Therefore, we have measured the total rate
constant at T = 295 and 202 K, and P = 0.4, 1 and 2 Torr. The
measurements are performed in a discharge - fa