Host–Guest Complexes of Oligopyridine Cryptands: Prediction of Ion Selectivity by Quantum Chemical Calculations

✍ Scribed by Ralph Puchta; Rudi van Eldik

• Book ID: 102166017
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 205 KB
• Volume: 2007
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200600715

✦ Synopsis

Abstract

The structures and complex‐formation energies for the cryptands 6,6′,6″,6″′,6″″,6″″′‐bis[nitrilotri(methylene)]tris(2,2′‐bipyridine) (1) and 2,2′,2″,9,9′,9″‐bis[nitrilotri(methylene)]tris(1,10‐phenanthroline) (2) with alkali and alkaline‐earth cations are obtained by PM3/SPASS and density functional (B3LYP/LANL2DZp) calculations and the results used to predict the ion selectivity. Both cryptands 1 and 2 have a cavity size similar to [2.2.2] and prefer Ca^2+^ and Sr^2+^, while 1 has a preference for K^+^ and 2 favours Na^+^ and K^+^. The cryptand flexibility for 1 is attributed mainly to the bipyridine building block and that for 2 to the groups neighbouring the bridgehead nitrogen atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)