The Effects of Molecular Anions on the Chemistry of Dark Clouds
  We have investigated the role of molecular anion chemistry in pseudo-time
dependent chemical models of dark clouds. With oxygen-rich elemental
abundances, the addition of anions results in a slight improvement in the
overall agreement between model results and observations of molecular
abundances in TMC-1 (CP). More importantly, with the inclusion of anions, we
see an enhanced production efficiency of unsaturated carbon-chain neutral
molecules, especially in the longer members of the families CnH, CnH2, and
HCnN. The use of carbon-rich elemental abundances in models of TMC-1 (CP) with
anion chemistry worsens the agreement with observations obtained in the absence
of anions.
