Chiral self-recognition in the gas phase:: the case of glycidol dimers

Supersonic jet FTIR spectra of the OH-stretching bands of glycidol monomers and clusters are presented. Chiral discrimination leads to marked differences in the absorption patterns of RR (SS) vs. RS glycidol dimers. The dominant absorption peaks are located at 3492 (RR, SS) and 3488 cm(-1) (RS) within a rich line spectrum with sizeable variations between enantiomerically pure and racemic dimers. A spectral difference technique is used to emphasize the intermolecular diastereomeric effects. Glycidol is possibly the first and likely the smallest molecule for which chiral self-recognition has been experimentally demonstrated in the gas phase. It thus lends itself very well to accurate quantum chemical calculations of the chiral discrimination effect. Qualitative results of exploratory calculations are reported.