Rotational and Vibrational State Distributions of HNC(0 0) from the Hot H Atom Reaction: H + (CN)2 → HNC + CN

Abstract

The reaction dynamics of the five-atom system, H + (CN)2, was investigated by probing the minor product channel producing the transient HNC molecule. The complete initial energy disposition, translation, rotation, and vibration was determined for the HNC(0 0), = 00,11, product. The reaction was studied under bulk conditions and was initiated by energetic H atoms with a mean translational energy of 92 kJ mol-1. The HNC molecule was monitored by time- and frequency-resolved absorption spectroscopy with sub-Doppler resolution. The initial rotational state distribution of each HNC(0 0) vibrational level was measured and found to be well-described by a Boltzmann distribution. Only two vibrational levels were detected so that the initial HNC product vibrational level distribution was determined as well. The absolute reaction cross section for the title reaction was measured to be 2 × 10-18 cm2 for H atoms with a nominal translational energy of 113 kJ mol.-1