Chiral discrimination on the host-guest-complexation of resorc[4]arenes with quarternary amines

Eur. J. Mass Spectrom. 10, 649–655 (2004)
DOI: 10.1255/ejms.675

Chiral discrimination on the host-guest-complexation of resorc[4]arenes with quarternary amines

Ahmad Mehdizadeh, Matthias C. Letzel, Michael Klaes, Ceno Agena and Jochen Mattay^*
Organische Chemie I, Fakultät für Chemie, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany. E-mail: mattay@uni-bielefeld.de

ABSTRACT:

The interaction of inherently chiral resorc[4]arenes with different chiral ammonium ions was measured by ESI-MS. For that purpose one enantiomer of the ammonium guests was labeled with deuterium to distinguish the enantiomers by their mass. We synthesized the ammonium salts by reaction of chiral primary amines with either CH₃I or CD₃I and analyzed the resulting ammonium iodides by NMR and optical rotation. The complexation experiments were performed by mixing the chiral host with various ratios of the unlabeled guest and its labeled enantiomer. By analysis of the integrals of the host- guest complexes we observed a chiral discrimination effect and a secondary isotope effect as well.

Keywords: host-guest chemistry, chiral discrimination/recognition, calixarene, resorc[4]arene, electrospray mass spectrometry

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