Methyl Acetate and its singly deuterated isotopomers in the interstellar
  medium
  Methyl acetate (CH_3COOCH_3) has been recently observed by IRAM 30 m radio
telescope in Orion though the presence of its deuterated isotopomers is yet to
be confirmed. We therefore study the properties of various forms of methyl
acetate, namely, CH_3COOCH_3, CH_2DCOOCH_3 and CH_3COOCH_2D. Our simulation
reveals that these species could be produced efficiently both in gas as well as
in ice phases. Production of methyl acetate could follow radical-radical
reaction between acetyl (CH_3CO) and methoxy (CH_3O) radicals. To predict
abundances of CH_3COOCH_3 along with its two singly deuterated isotopomers and
its two isomers (ethyl formate and hydroxyacetone), we prepare a gas-grain
chemical network to study chemical evolution of these molecules. Since gas
phase rate coefficients for methyl acetate and its related species were
unknown, either we consider similar rate coefficients for similar types of
reactions (by following existing data bases) or we carry out quantum chemical
calculations to estimate the unknown rate coefficients. For the surface
reactions, we use adsorption energies of reactants from some earlier studies.
Moreover, we perform quantum chemical calculations to obtain spectral
properties of methyl acetate in infrared and sub-millimeter regions. We prepare
two catalog files for the rotational transitions of CH_2DCOOCH_3 and
CH_3COOCH_2D in JPL format, which could be useful for their detection in
regions of interstellar media where CH_3COOCH_3 has already been observed.
