title: Differential and substrate-selective reactivity of calix[4]arene derivatives with cyclenyl-Zn(II) modifications at the upper rim.
abstract: [structure: see text] Novel "cone conformation" calix[4]arene derivatives, carrying either one or two cyclen (1,4,7,10-tetra-azacyclododecane) moieties at the upper rim, have been synthesized. The hydrolytic activities of the Zn(II) complexes of these calixarenes were studied. A surprising behavior was observed with p-nitrophenylstearate; whereas the bis-cyclenyl-2Zn(II) complex showed negligible hydrolytic activity over the background, the mononuclear complex showed a significant 400-fold rate increase at pH 8.5.
authors.affiliation: Department of Chemistry, Middle East Technical University, Ankara TR-06531, Turkey.
authors.forename: Gulsum
authors.initials: G
authors.lastname: Ozturk
authors.forename: Engin U
authors.initials: EU
authors.lastname: Akkaya