The synthesis of a cyclophane containing both a crown ether and an expanded porphyrin, sapphyrin, is described. This system acts as a receptor for the concurrent complexation of both anionic and cationic substrates.
Ammonium redox-responsive receptors containing two or three ferrocene redox-active centres attached to di- and tri-aza crown ether macrocycles
作者:Paul D. Beer、Declan B. Crowe、Brian Main
DOI:10.1016/0022-328x(89)85104-6
日期:1989.10
The binding of NH4+ to novel ferrocenyl aza crownethers 7 and 6, respectively, containing two and three ferrocene redox-active centres attached to amine functionalised di- and tri-aza crownethermacrocycles, results in large anodic shifts of the ferrocene/ferricinium redox couple, by up to 220 mV with 6.
Abstract Cyclic and acyclicligands containing the hydroxypyridinone (HOPO) moiety as donor group are known as strong coordinating compounds for a wide variety of metal ions. Based on the diaza-crown[18]ether Kryptofix K22, five different tendentate ligands were prepared using 1,2-HOPO, 1,2,3-HOPO and 2,3-Me-HOPO as additional binding moieties. The diaza-crown ether basic skeleton was furnished with
The new ditopic receptors 1-3 (Figure 1) have been synthesized and their binding ability for alkaline and transition metal cations has ben investigated by halide and W-Vis titrations. The recognition of complementary molecules through hydrogen bonding has been studied by H-1-NMR. The simultaneous recognition of these two guests is an anti-cooperative event. (C) 1999 Elsevier Science Ltd. All rights reserved.
New anion receptors based on cobalticinium-aza crown ether derivatives
作者:Paul D. Beer、Andrew R. Graydon
DOI:10.1016/0022-328x(94)88051-4
日期:1994.2
New mono- and bis-substituted amide-linked aza crown ether-cobalticinium compounds have been prepared and shown by H-1 nuclear magnetic resonance and electrochemical studies to accept chloride and bromide guest anions. Preliminary association constant determinations suggest that use of aza-crown-ether-complexed sodium cations in combination with an amide-linked positively charged cobalticinium redox centre leads to cooperative enhancement of the strength of anion complexation.