State-to-state photodynamics of nitrous oxide and the effect of long-range interaction on the alignment of O(1D2)

The photodissociation of N2O was studied around 203–205 nm by preparation of the parent molecule in a single rovibrational quantum state using a hexapole state-selector. The resulting photofragments N2(v, J) and O(1D2) were quantum-state selectively detected and their angular recoil distribution was measured using ion-imaging techniques. Information on the electronic alignment of the 1D2 state is obtained from analysis of the polarization sensitivity of the O(1D2) images using two different probe schemes. We present a theoretical analysis based on ab initio potential energy surface calculations and a semiclassical model incorporating the effects of the long-range quadrupole–quadrupole interaction between the N2 and O(1D2) fragments.