Molecular Torsion Balances: Evidence for Favorable Orthogonal Dipolar Interactions Between Organic Fluorine and Amide Groups

• DOI: 10.1002/anie.200702497
• Publication Date: 2007-09-26T16:49:13Z
• Authors: Felix R. Fischer; W. Bernd Schweizer; François Diederich
• Keywords: Amide; Non-covalent interactions

Finding the right balance: An indole-extended molecular torsion balance has geometry for measuring a truly orthogonal noncovalent interaction between CF bond dipole and an amide carbonyl group (see picture, green F, red O, blue N). Employing double-mutant cycle approach, negative free enthalpies were determined. Thus dipolar interactions can be new tool stabilizing protein–ligand complexes assembling supramolecular architectures.