High-Resolution Experimental Study on Photodissocaition of N2O

We study the photodissociation dynamics of nitrous oxide using the time-sliced ion velocity imaging technique at three photolysis wavelengths of 134.20, 135.30, and 136.43 nm. The O(S-1(J=0))+N-2(X-1 Sigma(+)(g)) product channels were investigated by measuring images of the O(S-1(J=0)) products. Vibrational states of N-2(X-1 Sigma(+)(g)) products were fully resolved in the images. Product total kinetic energy releases (TKER) and the branching ratios of vibrational states of N-2 products were determined. It is found that the most populated vibrational states of N-2 products are v=2 and v=3. The angular anisotropy parameters (beta values) were also derived. The beta values are very close to 2 at low vibrational states of the correlated N-2(X-1 Sigma(+)(g)) products at all three photolysis wavelengths, and gradually decrease to about 1.4 at v=7. This indicates the dissociation is mainly through a parallel transition state to form products at lower vibrational states, and the highly vibrational exited products are from a more bent configuration. This is consistent with the observed shift of the most intense rotational structure in the TKER as the vibrational quantum number increases.