Pair-correlated stereodynamics for diatom-diatom rotational energy transfer: NO(A2Σ+) + N2

Abstract

We have performed a crossed molecular beam velocity-map ion imaging study of state-to-state rotational energy transfer of NO(AΣ, v = 0, N = 0, j = 0.5) in collisions with N and have measured rotational angular momentum polarization dependent images of product NO(A) rotational levels N' = 3 and 5-11 for collisions at an average energy of 797 cm. We present an extension of our previously published [T. F. M. Luxford et al., J. Chem. Phys. 145, 174 304 (2016)] image analysis which includes the effect of rotational excitation of the unobserved collision partner and critically evaluate this methodology. We report differential cross sections and angle-resolved angular momentum alignment moments for NO(A) levels N' = 3 and 5-11 as a function of the rotational excitation of the coincident N partner. The scattering dynamics of NO(A) + N share similarities with those previously reported for NO(A) + Ne and Ar, although with detailed differences. We use comparison of the measurements reported here to the scattering of NO(A) with Ne, and the known NO(A)-Ne potential energy surface, to draw conclusions about the previously unknown NO(A)-N potential.

Correlated energy transfer in rotationally and spin–orbit inelastic collisions of NO(X2Π1/2, j = 1/2f) with O2(X3Σg−)

“…Rotational energy transfer to or from the collision partner will result in a lower or greater kinetic energy, respectively. In VMI, one measures the velocity distribution, such that these different kinetic energies lead to a series of nested spheres, 4 whose projections on the two-dimensional detector yield a set of concentric circles. These circles in principle contain the full kinematic information of the collision process, including the integral and differential state-resolved correlated cross sections.…”

“…It is, however, extremely challenging to experimentally resolve the individual circles, as the experimental blurring associated with, for instance, the collision energy spread and the crushing of spheres on the detector plane is in most cases much larger than the inherent spacing between the circles. [4][5][6][7][8][9][10][11][12] Recently, we reported the first observation of rotational product pair correlations in NO-O 2 inelastic collisions at a collision energy of 160 cm À1 , 13 by using a Stark decelerator to produce reagent beams of NO with very narrow velocity spread. 14 Here, we present a joint experimental and theoretical study of state-to-state resolved RET in the inelastic collisions of NO(X 2…”

Observation of correlated excitations in bimolecular collisions

“…Resolving the individual rings requires exceptional experimental resolutions, which are often not available in crossed beam experiments due to the velocity and angular spreads of the reagent beams. Recently, several state of the art experiments were performed to study collisions of NO and ammonia with several molecular collision partners (26)(27)(28)(29)(30)(31), however, the direct experimental observation of rotational product pairs has remained elusive.…”

Stereodynamics of rotational energy transfer in NO(A2Σ+) + Kr collisions

“…However, following our initial demonstration of the combination of optical state preparation of NO(A) with crossed molecular beams and VMI detection, [20][21][22] we have performed a series of systematic experimental and theoretical studies of rotationally inelastic collisions of NO(A). [23][24][25][26][27] In these experiments we have measured both DCSs and angle-resolved rotational alignment moments for the NO(A) + He, Ne and Ar systems. We observed quantitative agreement between experiment and theory for NO(A) + He, and very good agreement for NO(A) + Ar.…”