The effect of reagent rotation on steric requirements of elementary exchange reactions

The body-fixed coordinate system appears to be particularly suited for discussing the role of reagent rotation. The simple picture provided by the j_z-conserving approximation accords with the available evidence and with specially performed trajectory computations for the O + HCl(v= 0,j) and O + DCl(v= 0,j) reactions. An even simpler, Line-of-centers-type model is also discussed. Both the possible decline in reactivity at low rotational excitation and its increase at higher levels of excitation can be accounted for.