%0 Journal Article
%T A radical route to interstellar propylene formation
%A J. M. C. Rawlings
%A D. A. Williams
%A S. Viti
%A C. Cecchi-Pestellini
%J Physics
%D 2013
%I arXiv
%R 10.1093/mnrasl/slt113
%X Complex organic molecules, such as propylene (CH3CHCH2), are detected in molecular clouds (such as TMC1) with high fractional abundances (~2.10^{-9}, relative to hydrogen) that cannot be explained by gas-phase chemical reactions under normal dark cloud conditions. To obtain such high abundances requires an efficient grain-driven chemistry to be operating, coupled with effective desorption of the complex organics back into the gas-phase. We propose that the mechanism that we have previously described; rapid high density gas-phase chemistry in the gas released following sudden, total, ice mantle sublimation - can explain the high abundances, without recourse to ill-defined surface chemical pathways. Our model provides a natural explanation for why it is that some sources harbour high abundances of propylene, whilst others do not; based on the age and level of dynamical activity within the source (which affects the ice composition) and the chemical composition of the ambient gas.
%U http://arxiv.org/abs/1308.2559v1