Diagnostic value of photofragment anisotropy measurements: the predissociation mechanisms of the e1Pu state of N2

We report on a new method to identify the electronic symmetry of continuum state 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 e¹P_u(u = 0, J = 1.,9) levels of N₂. These levels predissociate by two different mechanisms to N(²P^o)+ N(⁴S^o) and N(²D^o) + N(⁴S^o) and each dissociation mechanism yields a different angular distribution.