Kinetic‐energy dependence of the reactions of $C+(2P)+N2$ from threshold to 28 eV CM

Guided‐ion‐beam mass spectrometry is used to examine the kinetic‐energy dependence of the reaction of ground‐state atomic carbon ion with molecular nitrogen. Integral reaction cross sections are measured for the three possible product channels: $N2+ + C,$ $CN+ + N,$ and $N+ + CN,$ all strongly endothermic. Thresholds for all three channels are found to be consistent with literature thermochemistry, although formation of $N2+$ is inefficient near threshold. The observed behavior suggests that the $Π3$ state of $CN+$ is either the ground state or within 0.14 eV of the ground state, and that $N2+$ is formed primarily in its $A 2Πu$ first excited state rather than the $X 2Σg+$ ground state. The thermochemistry measured here finds $ΔfH00(CN)=102±3$ kcal/mol, $D00(CN)=7.82±0.14 eV,$ and $IE(CN)=14.02±0.14 eV.$ The reaction mechanism for this system is explored by examination of the electronic state correlations and by phase‐space calculations.