Temperature Dependence of Collisional Energy Transfer in Ethyl Acetate

Article abstract of DOI:10.1021/j150643a030

Results are reported for the temperature and pressure dependence of the rate coefficient for the thermal unimolecular decomposition of ethyl acetate, obtained by using very low-pressure pyrolysis (VLPP) over the range 800-1150 K, both under conditions where only gas/wall collision occur and also (at 837 K) dilute in a number of bath gases (He, Ar, Ne, Kr, N2, and C2H4).Solution of the appropriate reaction-diffusion master equation yields from these data both the extrapolated high-pressure rate coefficient (10^12.7 exp(-201.5 kJ mol^-1/RT) s^-1) and the average downward collisional energy transfer, <ΔE_down>.The <ΔE_down> values are compared with those obtained for the same collision partners at ca. 340 K using multiple-photon dissociation (mpd).It is found that, for mon- and diatomic bath gases, <ΔE_down> is approximately proportional to T^-(0.1-0.3) (for He, Ne) and to T^-(0.3-0.5) (for Ar, Kr, N2).The combination of thermal and mpd techniques used here is generally applicable to obataining collisional energy-transfer data of highly vibrationally excited molecules over a wide range of temperatures and collision partners.