Host–guest complexes of mixed glycol-bipyridine cryptands: prediction of ion selectivity by quantum chemical calculations, part V

Beilstein Journal of Organic Chemistry

卷:9

Rudi van Eldik¹  Svetlana Begel¹  Ralph Puchta¹ 

[1] Inorganic Chemistry, Department of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstr. 1, 91058 Erlangen, Germany;

关键词: cryptands;    DFT;    quantum chemistry;    selective ion complexation;   

DOI  :  10.3762/bjoc.9.142

来源: DOAJ

【 摘 要 】

The selectivity of the cryptands [2.2.bpy] and [2.bpy.bpy] for the endohedral complexation of alkali, alkaline-earth and earth metal ions was predicted on the basis of the DFT (B3LYP/LANL2DZp) calculated structures and complex-formation energies. The cavity size in both cryptands lay between that for [2.2.2] and [bpy.bpy.bpy], such that the complexation of K+, Sr2+ and Tl3+ is most favorable. While the [2.2.bpy] is moderately larger, preferring Rb+ complexation and demonstrating equal priority for Sr2+ and Ba2+, the slightly smaller [2.bpy.bpy] yields more stable cryptates with Na+ and Ca2+. Although the CH2-units containing molecular bars fixed at the bridgehead nitrogen atoms determine the flexibility of the cryptands, the twist angles associated with the bipyridine and glycol building blocks also contribute considerably.

【 授权许可】

Unknown