Molecular recognition of barbiturates by a metalloreceptor

✍ Scribed by Arie R. van Doorn; David J. Rushton; Wilma F. van Straaten-Nijenhuis; Willem Verboom; David N. Reinhoudt

• Book ID: 104589453
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 615 KB
• Volume: 111
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19921111002

✦ Synopsis

Abstract

Metallomacrocycle 2, possessing an immobilized Lewis‐acidic uranyl cation, was synthesized by reaction of aldehyde 9 with 1,2‐cis‐cyclohexanediamine in the presence of Ba^2+^ as a template cation and subsequent transmetallation with UO~2~^2+^. Docking experiments with barbituric acid revealed that a ‐(CH~2~)~6~– spacer between the salen‐uranyl and 2,6‐diamidopyridine moieties of 2 is optimal. According to ^1^H NMR titration experiments, the barbituric acid complex of 2 is up to 2.7 kcal · mol^−1^ more stable than the complexes with five disubstituted derivatives. The flux of barbituric acid through a supported liquid membrane is enhanced 3.7 times by carrier 2 mediated transport.