Photodissociation of ClNO2 at 235 nm

The photodissociation of jet-cooled nitryl chloride ClNO2 + hv --> Cl + NO2 at 235 nm was investigated by resonance enhanced multiphoton ionisation/ti me-of-flight spectroscopy. In a one-colour experiment using nanosecond lase r pulses, the Cl ground state (P-2(3/2)) photofragment was detected and its speed distribution P(upsilon) and recoil anisotropy beta were obtained. Tw o contributions are observed in the P(upsilon) which are assigned to a Cl P -2(3/2), fragment emerging with a (X) over tilde (2)A(1) ground state and e lectronically excited (most likely in the (A) over tilde B-2(2) state) NO2 counterfragment, respectively. The recoil anisotropy was found to be beta = +1.1 +/- 0.1, yielding an upper limit of the dissociation lifetime of tau similar to 2 ps. (C) 1999 Elsevier Science B.V. All rights reserved.