INFLUENCE OF THE ELECTRONIC ASYMMETRY IN NH (1-DELTA) STATE LAMBDA DOUBLETS ON THE PHOTODISSOCIATION DYNAMICS OF HN3 AND DN3

The influence of the electronic asymmetry in the 1-DELTA(A') and 1-DELTA(A") LAMBDA doublets of NR (R = H,D) on the photodissociation dynamics of hydrazoic acid (R N3) has been investigated. Hydrazoic acid was prepared in its first excited electronic state, approximately A 1A". A variety of scalar (internal state and translational energy distribution) and vectorial (angular distribution, rotational alignment, correlation between translational and rotational motion) properties of the ejected NH or ND fragment were analyzed by LAMBDA-doublet-specific Doppler profile measurements. While the population of the 1-DELTA(A') and 1-DELTA(A") states are equal, the vector correlations for both LAMBDA-sublevels are different. NR(A") products are preferentially ejected in the original plane formed by the parent, and the recoil of NR fragments in the symmetric DELTA(A') state is preferentially perpendicular to that plane. The vector correlation between the translational and the rotational motion of the fragment also indicates a strong nonplanar dissociation geometry for NR products in the DELTA(A') state. About 50% of the ND(A') product rotation is generated by a torsional motion, while 80% of the ND(A") fragments are formed with J being aligned perpendicular to the recoil direction (M(J) = 0).