Crown Ether Ditopic Receptors for Ammonium Salts with High Affinity for Amino Acid Ester Salts
Two bis crown ether receptors were synthesized and tested as host molecules for protonated forms of alkyl amines and amino acid esters. Molecular recognition studies were conducted in CH2Cl2:MeOH (92:8) by spectrophotometric UV/Vis titrations and by spectrometric 1H NMR titrations in CDCl3. The calc...
| Autores: | , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2009 |
| País: | México |
| Recursos: | Universidad Autónoma del Estado de Morelos |
| Repositório: | Redalyc-UAEM |
| OAI Identifier: | oai:redalyc.org:47512356002 |
| Acesso em linha: | https://www.redalyc.org/articulo.oa?id=47512356002 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Química Amino Acid Crown Ethers Alkyl Ammonium Binding Constant Ditopic Receptors |
| Resumo: | Two bis crown ether receptors were synthesized and tested as host molecules for protonated forms of alkyl amines and amino acid esters. Molecular recognition studies were conducted in CH2Cl2:MeOH (92:8) by spectrophotometric UV/Vis titrations and by spectrometric 1H NMR titrations in CDCl3. The calculated binding constants are in the range 102-105 M-1. A high affinity for L-amino acid methyl ester derivatives was found. A theoretical study at the DFT level of the synthesized receptor and some analog ligands with three different ammonium ions helps to rationalize the experimentally found trends. |
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