title: First synthesis and structure of beta-ketoimine calix[4]arenes: complexation and extraction studies.
abstract: The synthesis of a new series of beta-ketoimine calix[4]arene derivatives is described. The reaction of calix[4]arene or p-tert-butylcalix[4]arene with bromoacetonitrile or bromobutyronitrile afforded di-, tri-, and tetranitrile calixarene derivatives (3-8, 3a), which were then reduced into the corresponding amine (9-13, 3b). The condensation of these aminocalixarenes with acetylacetone led to six beta-ketoimine calix[4]arene derivatives (14-18, 3c) as a class of selective receptors toward transition metals. Molecular structures of 4, 7, and 17 have been determined by X-ray diffraction. The packing of 17 revealed a network of intramolecular and intermolecular hydrogen bonds. The complexation properties of receptors 15, 17, and 3c toward different metal ions have been investigated by UV-vis titrations in organic media. The stoichiometries of complexes with 17 were determined by both the mole ratio method and Job plots. These novel receptors selectively complex Cu2+, Hg2+, and Ag+. Moreover, the extraction properties of 17 toward cations have been studied by liquid-liquid extraction and atomic absorption spectrometry. Compound 17 has good affinity and selectivity toward Pb2+.
authors.affiliation: Laboratoire d'Application de la Chimie à l'Environnement, UMR 5634, Université Claude Bernard, Lyon1, 69622 Villeurbanne Cedex, France.
authors.forename: Hatem
authors.initials: H
authors.lastname: Halouani
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dumazet-Bonnamour
authors.forename: Monique
authors.initials: M
authors.lastname: Perrin
authors.forename: Roger
authors.initials: R
authors.lastname: Lamartine