Gas-phase complexes:: noncovalent interactions and stereospecificity

Chiral recognition is a fundamental phenomenon in life sciences based on the enantioselective complexation of a chiral molecule with a chiral selector. The diastereomeric aggregates, formed by complexation, are held together by a different combination of intermolecular forces and are, therefore, endowed with different stability and reactivity. Determination of these forces, which are normally affected in the condensed phase by solvent and supramolecular interactions, requires the generation of the diastereomeric complexes in an isolated state and their kinetic and spectroscopic investigation. This paper concerns enantiodiscrimination of chiral molecules in the gas phase through the application of various ESI-MSn-CID and REMPI-TOF methodologies. The measurement of the fragmentation thresholds of diastereomeric clusters by these techniques allowed to shed light upon the nature and the magnitude of the intrinsic interactions which control their formation and which affect their stability and reactivity. (C) 2002 Elsevier Science B.V. All rights reserved.