The C($^{\mathrm{3}}$P) $+$ NH$_{\mathrm{3}}$ reaction in interstellar chemistry.

The kinetics and product formation channels of ground state carbon atoms, C($^{\mathrm{3}}$P), reacting with ammonia, NH$_{\mathrm{3}}$, have been investigated using two complementary experiments and electronic structure calculations. Reaction products are detected in a gas flow tube experiment (330 K, 4 Torr) using tunable vacuum-ultraviolet photoionization coupled with time of flight mass spectrometry. Temporal profiles of the species formed and photoionization spectra are used to identify primary products of the C $+$ NH$_{\mathrm{3}}$ reaction. In addition, C($^{\mathrm{3}}$P) decay and H-atom formation are monitored by laser induced fluorescence from room temperature to 50 K in a supersonic gas flow. The combination of experiments supported by theoretical calculations indicates that in the temperature and pressure range investigated, the H $+$ H$_{\mathrm{2}}$CN production channel represents 100{\%} of the product yield for this reaction. The effects of the new rate constants on interstellar nitrogen hydride abundances using a model of dense interstellar clouds are discussed.