Data from: Dipoles affect conformational equilibrium

Electric dipoles are ubiquitous. They affect charge transfer,
self-assembly, materials performance, and enzymatic activity. Herein, we
demonstrate dipole effects on molecular geometry. An aromatic amide,
5-N-amide derivative of anthranilamide (Aaa), assumes two stable
conformations with drastically different dipole moments. In non-polar
solvents, Aaa exists predominantly as the conformer with the smaller
dipole as nuclear Overhauser effect (NOE) and density-functional theory
(DFT) analysis reveal. Increasing medium polarity drives the emergence of
the other structure with the larger dipole. Splitting of the NMR signals
at low temperature is consistent with capturing the two Aaa conformers
upon its aggregation. Analysis employing density-functional theory
quantifies the dynamics of the equilibrium between the two conformations
and how solvent polarity affects it. This synergy between molecular
electric dipoles and medium polarity reveals a paradigm for conformational
switching.