Journal of the Mexican Chemical Society
versión impresa ISSN 1870-249X
ROSETE-LUNA, Sharon; MEDRANO, Felipe; BERNAL-URUCHURTU, Margarita I. y GODOY-ALCANTAR, Carolina. Crown Ether Ditopic Receptors for Ammonium Salts with High Affinity for Amino Acid Ester Salts. J. Mex. Chem. Soc [online]. 2009, vol.53, n.4, pp.209-219. ISSN 1870-249X.
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.
Palabras llave : Ditopic Receptors; Binding Constant; Crown Ethers; Alkyl Ammonium; Amino Acid.