Alkali Metal Cation Binding of Tetraethyl Resorcarene: An Ab Initio and Mass Spectrometry Study

Abstract

The complex formation between alkali metal cations (Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺) and the most stable conformation of tetraethyl resorcarene, the C ⁴ crown, was studied by ab initio methods. The conformational change of the host resorcarene, the most favourable binding locations and the relative binding energies of the cations are reported. In addition, mass spectrometric H/D exchange reactions were carried out; the divergent results obtained for the lithium complex are well explained by the results obtained in the ab initio calculations.

Keywords:

• Supramolecular complexes
• Resorcarenes
• H/D exchange
• ESI mass spectrometry

Acknowledgements

Funding by the Academy of Finland, Grant 68194, is gratefully acknowledged.

Notes

^†IUPAC name: 2,8,14,20-tetraethyl-5,11,17,23-tetramethylpentacyclo-[19.3.1.1^13,7.1^9,13.1^15,9]octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene-4,6,10,12,16,18,22,24-octol.

^‡Basis sets were obtained from the Extensible Computational Chemistry Environment Basis Set Database, Version 7/30/02, as developed and distributed by the Molecular Science Computing Facility, Environmental and Molecular Sciences Laboratory, which is part of the Pacific Northwest Laboratory, PO Box 999, Richland, WA 99352, USA, and funded by the US Department of Energy. The Pacific Northwest Laboratory is a multiprogram laboratory operated by Battelle Memorial Institute for the US Department of Energy under contract DE-AC06-76RLO 1830. Contact David Feller or Karen Schuchardt for further information.