Imaging isocyanic acid Photodissociation at 193 nm: The NH (a1Δ) + CO (X1Σ+) Channel
Zhiguo Zhang,a* Min Xin,a* Shutao Zhao,a and Yang Chenb*
Isocyanic acid (HNCO) as a small molecule of four atoms is a model system for studying the process of multiple dissociation channels. It plays an important role in the field of combustion chemistry, environmental chemistry and other fields. The photodissociation dynamics of isocyanic acid has been studied by the time-sliced velocity map ion imaging technique at 193 nm. The center-of-mass translational energy distribution derived from the NH(a1Δ) images imply that the CO vibrational distributions are inverted for most of the measured 1NH(v|j) internal states. A bimodal rotational state distribution of CO(v) has been observed, which coincide with the theoretical results. This result implies that isocyanic acid dissociates in the S1 state in two different pathways.