Dissociative photoionization of N2O: Analytical photoion spectroscopy

N-loss photodissociation dynamics of N2O+(B2Π) near the NO+(Σ+1) + N(2P) dissociation limit

Photodissociation dynamics of the N₂O⁺ cation in its B²Π state has been experimentally studied in an energy region around the NO⁺(¹Σ⁺) + N(²P) dissociation limit using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The results show that the NO⁺(¹Σ⁺) + N(²D) product channel dominates the dissociation dynamics and requires the NNO angle to change by 30°-50° prior to dissociation. The NO⁺(¹Σ⁺) + N(²P) product channel, which directly correlates with the B²Π state but less competitive, opens immediately when the photon energy reaches the dissociation limits, indicating a flat dissociation pathway without bending on the B²Π state surface.

Dissociative photoionization of N2O in the region of the N2O+(B 2Π) state studied by ion–electron velocity vector correlation

Dissociative direct photoionization of the N2O(X 1Sigma+) linear molecule via the N2O+(B 2Pi) ionic state induced by linearly polarized synchrotron radiation P in the 18-22 eV photon energy range is investigated using the (VA+,Ve,P) vector correlation method, where VA+ is the nascent velocity vector of the NO+, N2+, or O+ ionic fragment and Ve that of the photoelectron. The DPI processes are identified by the ion-electron kinetic energy correlation, and the IchiA+(thetae,phie) molecular frame photoelectron angular distributions (MFPADs) are reported for the dominant reaction leading to NO+ (X 1Sigma+,v) + N(2D)+ e. The measured MFPADs are found in satisfactory agreement with the reported multichannel Schwinger configuration interaction calculations, when bending of the N2O+(B 2Pi) molecular ion prior to dissociation is taken into account. A significant evolution of the electron scattering anisotropies is observed, in particular in the azimuthal dependence of the MFPADs, characteristic of a photoionization transition between a neutral state of Sigma symmetry and an ionic state of Pi symmetry. This interpretation is supported by a simple model describing the photoionization transition by the coherent superposition of two ssigma and ddelta partial waves and the associated Coulomb phases.