CN Emission in Active Nitrogen. II. The Role of Energy Transfer and Atom Transfer Reactions in CN(X²Σ⁺) Excitation

A simplified mechanism is presented for excitation of ground state CN(X 2 Σ + ) formed from carbonaceous impurity in flowing N 2 subjected to a microwave discharge. Analysis of absolute intensity data from spectrometer recordings of CN(B 2 Σ + → X 2 Σ + ) violet band emission enabled order of magnitude estimates of rate constants for CN(X 2 Σ + ) excitation by energy transfer from vibrationally excited ground state nitrogen, [Formula: see text][Formula: see text]and formation of electronically excited NCN* in a three body reaction[Formula: see text]Energy transfer from [Formula: see text] is shown to be a minor source of excitation of CN to radiative levels. N 2 (A) is a source of vibrationally excited ground state nitrogen, [Formula: see text] which in turn excites CN. Vibrational population profiles under all conditions in this work are shown to be primarily a function of [Formula: see text] Evidence for the participation of the A 2 Π state of CN is shown in the population maxima at ν = 4 and 10 of the B 2 Σ + state.