A crossed molecular beam investigation of the N(2D) + pyridine reaction and implications for prebiotic chemistry

The reactivity of the prototypical aromatic six-membered N-heterocyclic pyridine is of relevance in atmospheric/ combustion chemistry, as well as astrochemistry and prebiotic chemistry. Yet, experimental/theoretical studies of elementary reactions involving pyridine are scarce, with little information on primary reaction products and their branching fractions (BFs). Here, we report crossed molecular beam studies of the reaction of electronically excited atomic nitrogen, N(2D), with pyridine. This reaction can proceed via ring-contraction (BF approximate to 0.35) or Hdisplacement (BF approximate to 0.65) mechanisms, while the inclusion of N(2D) into the ring leads to pyrimidine + CH. Implications for prebiotic chemistry and the chemistry of Saturn's moon Titan are noted.