Chirality-Induced Switch in Hydrogen-Bond Topology: Tetrameric Methyl Lactate Clusters in the Gas Phase


  • Support by the DFG research training group GRK 782 and the Fonds der Chemischen Industrie is acknowledged. We are grateful to A. de Meijere for advice on nomenclature, U. Buck, C. Rice, and U. Schmitt for help and discussions, and A. Bochenkova for preliminary MP2 studies.


original image

Supersonic jet expansions of racemic methyl lactate show a prominent OH-stretching infrared absorption at 3401 cm−1 which is not present in the enantiopure compound. Experimental results and quantum chemical calculations show that the underlying tetrameric cluster has 2:2 stoichiometry of the R and S isomers and S4 symmetry (see picture; C orange, O red, H gray).