Poly-Lewis Acids

Poly-LEWIS-Acids are molecules with multiple LEWIS-acidic functions linked by an organic skeleton. They can be used as receptors for anionic or neutral LEWIS bases, with which they form a LEWIS-acid-base adduct. The host system can be rigid to flexible or cage-like, and typical LEWIS-acidic functions are those based on group 13 and 14 elements. Depending on the spatial orientation of the organic backbone and the distance between the LEWIS-acidic functions, as well as the steric and electronic properties of the substituents, suitable guest molecules can be selectively bound. Systems studied in our group include the bidentate 1,8-diethynylanthracene and its tetradentate photo­dimer, as well as larger representatives such as the three- and sixfold functiona­lized trisilacyclohexane and tribenzotriquinacene.

The structures of the adducts can be studied using X-ray diffraction on single crystals, while the dynamics and energetics of adduct formation can be understood by DOSY-NMR experiments as well as quantum chemical calculations.