Erkennung und Nachweis von Anionen: gegenwärtiger Stand und Perspektiven

Abstract

Die Chemie der Anionenerkennung hat sich seit ihren Anfängen in den späten sechziger Jahren des 20. Jahrhunderts stark entwickelt. Anfangs waren nur positiv geladene Ammonium‐Cryptanden als Rezeptoren für Halogenid‐Ionen bekannt. Nun, am Ende des Millenniums, sind eine Vielzahl geladener und neutraler, cyclischer und acyclischer, anorganischer und organischer supramolekularer Wirte für die selektive Komplexierung, den Nachweis und die Trennung anionischer Gastmoleküle verfügbar. Bei der Anionenerkennung spielen Solvatationseffekte und der pH‐Wert eine entscheidende Rolle. In jüngerer Zeit wurden wichtige Fortschritte bei Synthesen mit anionischen Templaten, der durch Anionen gesteuerten Selbstorganisation, der Ionenpaarerkennung und der Funktion von Anionen bei der supramolekularen Katalyse erzielt.

Four transition metal complexes constructed with mixed mercaptotetrazole and 4,4′-bipyridine ligands

“…Herein, we present four transition coordination polymers containing mtms (Scheme 1) and bpy (Scheme 2) coligands, namely {[Cd 2 (mtms)(bpy) 2 4 ]ÁH 2 O} n (4).…”

“…The Cd atom is in a distorted octahedral geometry, with three N atoms from three bpy ligands, two O atoms from two coordinated water ligands, and one S atom from an mtms ligand. The mtms ligand adopts an S-bonding monodentate coordination mode (Scheme 1, mode II), and the tetrazole ring is on the outside, as also found in our previously reported mercaptotetrazole complexes [Cd(mtz) 2 mode I, IV), coordinated water, and the uncoordinated O atom of the mtms ligand (Fig. 2b ).…”

“…Chemical templates have an important role in the formation of complexes containing multiple components that have defined structural assemblies [1,2]. Several previous studies have shown that geometries and sizes of ligands, the coordinating ability of anions, and the nature of metals are all important in determining the structures of such complexes [3][4][5][6][7][8].…”

A TD‐DFT study on the cyanide‐chemosensing mechanism of 8‐formyl‐7‐hydroxycoumarin

“…6 Among the various chemosensors, fluorescent chemosensors have many advantages, including high sensitivity, low cost, ease of detection, and suitability as diagnostic tools for biological concerns. [8][9][10][11][12][13] Different anions can be easily discerned with the naked eye by virtue of the distinct fluorescence wavelengths that they elicit. 14 Unfortunately, this spectroscopic technique provides only indirect information about spectrophotometrical properties and geometries involved in the sensing process.…”

Ditopic Binding of Alkali Halide Ions to Trimethylboroxine

“…1,2 Recently, the ion-pair binding 3 has attracted much attention because of the potential application in zwitterion recognition and/or selective extraction of zwitterionic species of environmental importance. 4,5 Both cation and anion co-operatively bind to the ditopic receptors that possess the separate binding site for each charge type; the binding of one charged species induces the subsequent binding of the counter ion.…”