Imaging the Effect of Reactant Rotations on the Dynamics of the Cl + CHD3(v1 = 1, |J,K⟩) Reaction.

The effect of the rotational excitations of CHD3(v1 = 1, |J,K⟩) in reaction with the Cl atom was investigated in a crossed-beam, product-imaging experiment over the collisional energy (Ec) range 1-6 kcal mol(-1). It was found that the initial J- and K-selections affect only the total reactivity, not the more detailed product-state and angular distributions-a surprising result that defies conventional wisdom. Although the higher reactivity with increasing J states could be understood as a result of a wider range of attack angles near the barrier, the observed K-propensity of σ|J0⟩ < σ|JJ⟩ for J = 1 at Ec < 2 kcal mol(-1), opposite to that reported previously at higher Ec's, is perplexing and yet to be explained.