Direct structural determination of conformations of photoswitchable molecules by laser desorption-electron diffraction

Fluorine in charge! The fluorine-iminium ion gauche effect has been exploited in the design of conformational probes for organocatalysis (see scheme). Stabilizing hyperconjugative [σ C- H→σ^*C-F] and/or electrostatic [N⁺ F ^δ-] interactions render the C-F bond an excellent steering group for controlling molecular topology without introducing additional steric constraints.