Diagnostic value of photofragment anisotropy measurements: Predissociation mechanisms of the e1 Pi(u) state of N-2

We report on a new method to identify the electronic symmetry of continuum states involved in the predissociation of long-lived rotational levels of diatomic molecules. The angular distribution of atomic fragments resulting from photodissociation is used to elucidate the dissociation mechanism. We applied this method to the e (1) Pi(u) (v = 0, J = 1,...,9) levels of N-2. These levels predissociate by two different mechanisms to N(P-2(o)) + N(S-4(o)) and N(D-2(o)) + N(S-4(o)) and each dissociation mechanism yields a different angular distribution.