Complete characterization of the constrained geometry bimolecular reaction O ( D 1 ) + N 2 O → NO + NO by three-dimensional velocity map imaging

The bimolecular reaction O ( D 1 ) + N 2 O → NO + NO was photoinitiated in the ( N 2 O ) 2 dimer at a wavelength of 193 nm and was investigated by three-dimensional (3D) velocity map imaging. State selective 3D momentum vector distributions were monitored and analyzed. For the first time, kinetic energy resolution and stereodynamic information about the reaction under constrained geometry conditions is available. Directly observable NO products exhibit moderate vibrational excitation and are rotationally and translationally cold. Speed and spatial distributions suggest a pronounced backward scattering of the observed products with respect to the direction of motion of the O ( D 1 ) atom. Forward scattered partner products, which are not directly detectable are also translationally cold, but carry very large internal energy as vibration or rotation. The results confirm and extend previous studies on the complex initiated reaction system. The restricted geometry of the van der Waals complex seems to favor an abstraction reaction of the terminal nitrogen atom by the O ( D 1 ) atom, which is in striking contrast to the behavior observed for the unrestricted gas phase reaction under bulk conditions.