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 N-2(nu, J) and O(D-1(2)) were quantum-state selectively detected and their angular recoil distribution was measured using ion-imaging techniques. Information on the electronic alignment of the D-1(2) state is obtained from analysis of the polarization sensitivity of the O(D-1(2)) 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 N-2 and O(D-1(2)) fragments. (C) 2000 Elsevier Science B.V. All rights reserved.