Study of conformational behavior of CMP(O)-cavitands by NMR spectroscopy and X-ray analysis in relation to the extraction properties
| Autor: | Boerrigter, Harold, Verboom, Willem, Hulst, Ron, van Hummel, Gerrit J., Harkema, Sybolt, Reinhoudt, David N., Pons, M. |
|---|---|
| Přispěvatelé: | Faculty of Science and Technology, Molecular Nanofabrication |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
ROESY spectrum
Picrate Conformational behavior Substituent Cavitand Fluorine-19 NMR Nuclear magnetic resonance spectroscopy Nuclear magnetic resonance crystallography chemistry.chemical_compound Crystallography chemistry Amide Extraction property Transverse relaxation-optimized spectroscopy Amide moiety Trivalent actinide |
| Zdroj: | NMR in Supramolecular Chemistry, 19-35 STARTPAGE=19;ENDPAGE=35;TITLE=NMR in Supramolecular Chemistry NMR in Supramolecular Chemistry ISBN: 9789401059503 |
| ISSN: | 1389-2185 |
| Popis: | Tetra-CMP(O)-functionalized cavitands are very effective europium(III) extractants. Cavitand 1b is the strongest ligand and has the highest extraction constant for 1:1 complexation with Eu(picrate)3 (viz. Kex 1 = 2.7 × 1012M−4). The conformational behavior of the CMP(O) cavitands 1a,b and 2a,b was studied by means of NMR spectroscopy. The introduction of an N-propyl substituent imposes large conformational differences due to inhibition of the free rotation around the amide N-C(O) bond. The Gibbs free energy of activation is about 75 kJ/mol for a rotation around the amide moiety (inwardoutward motion). The N-propyl-substituted cavitands form clusters; this aggregation originates from the association of propyl and pentyl chains of the cavitand molecules. The ability of bromomethylcavitand 3 to complex solvent molecules (e.g. CH2C12 or toluene) in the cavity is illustrated by a single crystal X-ray structure (with CH2C12). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|