TETRAHEDRON, cilt.61, sa.35, ss.8345-8350, 2005 (SCI-Expanded)
Lariat ether carboxylic acids of structure CECH2OCH2C6H4-2-CO2H with crown ether (CE) ring sizes of 12-crown-4, 15-crown-5 and 18-crown-6 are prepared and converted into alkali metal-lariat ether carboxylate complexes. Absorptions for the diastereotopic benzylic protons in the H-1 NMR spectra of the complexes in CDCl3 are utilized to probe the extent of side arm interaction with the crown ether-complexed metal ion as a function of the crown ether ring size and identity of the alkali metal cation. (c) 2005 Elsevier Ltd. All rights reserved.