Energy partitioning in the 532 nm photofragmentation of nitrosyl cyanide (NCNO)

The 532 nm photodissociation of gaseous NCNO has been studied by a tandem pulse technique utilizing repetitive nanosecond laser pulses for dissociation and for delayed, time-correlated laser-induced fluorescence probing. Dissociation occurs within less than 3 ns, and both CN(X) and NO(X) have been identified as primary fragments. The central portions of their rotational distributions correspond to Boltzmann distributions with temperatures of (1010 ± 50) K for CN and (930 ± 50) K for NO. Parent rotation and angular momentum from bending vibrations of the A state levels populated at 532 nm account for the observed fragment rotation. Little angular momentum is partitioned into orbital motion of the fragments indicating that the molecule dissociates from a linear or quasilinear nuclear configuration. The observed distribution of the 9300 cm^-1 of available energy into internal and relative translational degrees of freedom of the fragments is consistent with predissociation of bound à state levels into the continuum of ground state NCNO. © 1983 American Institute of Physics.