No abstract

The description of C 3 hydrocarbon chemistry in current photochemical models of Titan's atmosphere is found to be far from complete. We have carefully investigated the photochemistry involving C 3 H p compounds in the atmosphere of Titan (considering both photolysis and neutral reactions), which considerably impacts the abundances of many other hydrocarbon species (including C 2 compounds). Model results indicate that three species (C 3 , c−C 3 H 2 and C 3 H 3 ) could be abundant enough to be present in the Cassini/INMS data. Because the error bars on predicted C 3 -hydrocarbon abundances are considerably larger than those of the observational data, new experimental and theoretical studies targeting the measurement of low-temperature reaction rate constants and product branching ratios are required to reduce current model uncertainties. In particular, we highlight 30 "key reactions", the uncertainty factors of which should be lowered to improve the quality of photochemical models involving C 3 H p molecules.

Kinetic and Theoretical Studies of the Reactions CH3C(0)02 + N02 + M *e CH3C(0)02N02 + M between 248 and 393 K and between 30 and 760 Torr