Alternating Stereospecificity upon Central-Atom Change: Dynamics of the F +PH Cl S 2 Reaction Compared to its C- and N-Centered Analogues.

Central-atom effects on bimolecular nucleophilic substitution (S 2) reactions are well-known in chemistry, however, the atomic-level S 2 dynamics at phosphorous (P) centers has never been studied. We investigate the dynamics of the F +PH Cl reaction with the quasi-classical trajectory method on a novel full-dimensional analytical potential energy surface fitted on high-level ab initio data. Our computations reveal intermediate dynamics compared to the F +CH Cl and the F +NH Cl S 2 reactions: phosphorus as central atom leads to a more indirect S 2 reaction with extensive complex-formation with respect to the carbon-centered one, however, the title reaction is more direct than its N-centered pair.