This paper concerns the semiclassical description, calculation and measurement of angular momentum polarization in the products of elementary gas-phase bimolecular reactions. A unified, semiclassical treatment of the centre-of-mass correlated (k,k′,j′) angular distribution involving the reagent and product relative velocity and the product angular momentum vectors is described, and is related to other methodologies already existing in the literature. Explicit expressions are provided enabling experimentalists to extract rotational polarization information from crossed-molecular beam and photon-initiated reaction studies, under a variety of experimental conditions. Furthermore, the strategy developed is well suited to the theoretical calculation of reaction product polarization, in particular, using classical trajectory methods. An illustrative example of such a calculation is presented, and the centre-of-mass polarization data provided is used to simulate the laboratory frame rotational moments that can be determined experimentally using 1+1 Doppler-resolved polarized Laser product probing techniques.

in this issue, is divided into two parts. In the first, equations for the laboratory (LAB) velocity distribution of products generated via photoionitiated bimolecular reaction are presented. These equations provide the basis for numerical simulation of these distributions from assumed forms for the centre-of-mass (CM) differential cross-section : the results may be compared directly with those derived experimentally via Fourier-transform Doppler 1 + 1 LIF or REMPI spectroscopy. The latter inversion technique is described in detail in the second part of the paper.

Velocity-aligned, superthermal O(1D) atoms generated via the photodissociation of N2O have been employed to investigate the stereodynamics of the title reaction. The power of this experimental technique, when coupled with Doppler-resolved, polarized laser-induced fluorescence probing of the reaction products, is demonstrated by reference to the specific reaction channel leading to NO(υ′=0)+NO(υ′=16,17), which is shown to proceed via direct stripping dynamics. Furthermore, the observed product-state selective linear and angular momenta disposals imply that the reaction is stereodynamically constrained to occur via collinear collision geometries.

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The application of polarised, Doppler-resolved laser-induced fluorescence (LIF) probing of the products scattered from photon-induced ' half-collision ' (photodissociation) and 'full-collision ' (bimolecular reaction) processes is developed to include the velocity dependence of their stereodynamics. Fourier-transform inversion procedures are used to derive the products' speed distributions W(v') and vector correlations Blj(v') (a) in the photodissociation of HONO, and (b) in the bimolecular reaction of O('D) with CH, . In the former example, they provide new insight into the stereodynamics of the photodissociation HONO, + hv 4 HO(v = 0, N ) + NO,(%, A) In the latter, together with newly developed LAB --+ CM simulation methods, they provide new insight into the ste reod y n am ics of the react ion O('D) + CH, --+ OH(v = 4, N) + CH,The OH is shown to be generated with its rotational angular momentumj', constrained to lie in a plane directed perpendicular to its centre-of-mass relative velocity, k'.