Photodissociation of ClNO2 at 235 nm

The photodissociation of jet-cooled nitryl chloride ClNO2+hν→Cl+NO2 at 235 nm was investigated by resonance enhanced multiphoton ionisation/time-of-flight spectroscopy. In a one-colour experiment using nanosecond laser pulses, the Cl ground state (2P3/2) photofragment was detected and its speed distribution P(v) and recoil anisotropy β were obtained. Two contributions are observed in the P(v) which are assigned to a Cl 2P3/2 fragment emerging with a X̃ 2A1 ground state and electronically excited (most likely in the à 2B2 state) NO2 counterfragment, respectively. The recoil anisotropy was found to be β=+1.1±0.1, yielding an upper limit of the dissociation lifetime of τ∼2 ps.