Rates of enantiomerization in axially chiral 2,2′-bipyridines with restricted rotation: an ab initio study

Abstract

Herein, we describe our findings concerning a 6,6′-bridged-2,2′-bipyridine derivative whose dynamic properties were described by Rebek and Trend in 1978. While the enantiomerization processes of the neutral molecule, the dication and the Zn complex were correctly described by DFT calculations, those of the monoprotonated cation were in disagreement. This led us to search for possible explanations, which led us to conclude that the experimental barrier corresponds to a N–H⋯O CMe 2 hydrogen bonded complex between the cation and one solvent molecule.