Stereodynamical effects with laser-prepared reagents

Stereodynamical effects with laser-prepared reagents 

Since the early days of reaction dynamics, the vectorial character of the elementary chemical reaction has been well recognized. In this view, not only are scalar quantities such as collision energy or total reaction cross-section important in governing the reactive collision, but also vectorial properties such as the 

For the reaction A + BC AB + C, the partition of the total angular momentum J between the initial and flnal momentum of the colliding particles L, V and the rotational momenta of the reactant and product molecules j,f has been shown to be very useful in the diagnosis of the reaction dynamics. The main problem is that even if one lets two molecular beams collide with well-defined speeds and directions, one cannot select the impact parameter and its azimuthal orientation about the initial relative velocity vector. A currently popular way to circumvent this lack of resolution is to use vector correlations, particularly in laser studies, photofragmentation dynamics and, more generally, the so-called field of dynamical stereochemistry . One of the most commonly used correlations is that between the product rotation angular momentum and the initial and final relative velocity vectors. 

For the limiting cases, i.e. pure parallel or perpendicular transitions, jS takes the values +2 and —1 respectively. An isotropic angular distribution is represented by = 0. 

The other correlations fi v, v j and fi v j can be extracted using narrow-band and sub-Doppler polarization spectroscopy, e.g. from the analysis of the Doppler profiles at different geometries (e.g. see Dixon (1986) for a full discussion of this topic). 

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Stereodynamical effects with laser-prepared reagents... 

STEREODYNAMICAL EFFECTS WITH LASER-PREPARED REAGENTS... 

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