title: Construction of pendant-armed Schiff-base macrocyclic dinuclear zinc complexes and their selective recognition of acetate ions.
abstract: Two new flexible extended dialdehydes (H2hpdd and H2pdd) with different functional pendant arms (-CH2CH2PhOH and -CH2CH2Ph) have been synthesized and reacted with 1,2-bis(2-aminoethoxy)ethane to prepare Schiff-base macrocyclic complexes in the presence of a Zn(II)-ion template. As a result, two preorganized dinuclear Zn(II) intermediates (1 and 2), as well as two 42-membered folded [2+2] macrocyclic dinuclear Zn(II) complexes (3 and 4), were produced. The central zinc ions in compounds 1-4 showed distinguishable coordination patterns with the dialdehydes and the [2+2] macrocyclic ligands, in which a subtle pH-adjustment function of the two pendant arms (with or without the phenolic hydroxy group) was believed to play a vital role. Furthermore, cation- and anion-recognition experiments for complexes 3 and 4 revealed that they could selectively recognize acetate ions by the formation of 1:1 stoichiometric complexes, as verified by changes in their UV/Vis and MS (ESI) spectra and even by the naked eye.
authors.affiliation: State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (P. R. China), Fax: (+86) 2583314502.
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Jin
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Chen
authors.forename: Gui
authors.initials: G
authors.lastname: Yin
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
keywords: Schiff bases; acetate; anion recognition; macrocycles; zinc