Consequences of the ‘Pedersen papers’ on crown type chemistry at Würzburg and Bonn Universities: From heteroaromatic crowns and podands to large molecular and crystalline cavities including multisite receptors,cascade molecules,chromoionophores, siderophores,surfactant-type,and extreme ligands

We thank the editors of this issue for the opportunity to present the historic development of crown chemistry at the Universities of Wurzburg and Bonn in memory of C. J. Pedersen, the originator of the crown ethers. His legacy of science has tremendously stimulated research at both universities.This paper is dedicated to the memory of the late Dr C. J. Pedersen.     

Efficient Route for the Synthesis of New Dinaphthosulfoxide Aza Crowns Using Ethyleneglycol Under Microwave (MW) Irradiation: Macrocyclization is Preferred to Oligomerization Under MW Irradiation

Abstract

New dinaphthosulfoxide aza crowns were prepared from the corresponding dinaphthosulfoxide diester and diamines under reflux conditions (conventional heating) and microwave (MW) irradiation. These reaction routes were used for the synthesis of a series of aza crowns, such as dinaphthosulfide, dinaphthosulfone, dibenzosulfide, and dibenzosulfoxide. The synthesis of aza crowns under MW irradiation in comparison with conventional heating has several advantages, such as shorter reaction times, simpler reaction conditions, and the use of ecofriendly solvents, higher yields, and regioselectivity. In the MW synthesis, macrocyclization is preferred to oligomerization, and thus, the yields of byproducts are low.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT      

Synthesis, optical and electroanalytical characterizations of a thiacalix[4](N-phenylazacrown-5)ether-BODIPY ionophore

Novel fluorogenic 1,3-alt thiacalix[4](N-phenylazacrown-5)ether ionophore has been synthesized by conjugation of the N-phenyl group with borondipyrromethene (BODIPY) fluorophore moiety. The ionophore exhibits pronounced off-on type fluorescent responses to some transition metal ions, in particular to Cu²⁺. In a PVC membrane electrode, distinct Ag⁺ selectivity was observed in potentiometric transduction.     

Unprecedented cyclisations of calix[4]arenes with glycols under the Mitsunobu protocol. Part 1: A new perspective for the synthesis of calixcrowns

Selective ring closures of p-tert-butylthiacalix[4]arene and p-tert-butylcalix[4]arene with oligoethylene glycols were performed under the Mitsunobu protocol using the DEAD/TPP system. The method opens a new perspective for the syntheses of 1,3-calixcrowns.     

Magnesium-25 NMR studies of magnesium salts and complexes in nonaqueous solvents

Magnesium-25 NMR measurements were carried out on aqueous and non-aqueous solutions of magnesium salts. In the former case the²⁵Mg resonance frequency was independent of the concentration or of the counterion. In nonaqueous solvents, however, the resonance frequency was dependent on the solvent, the concentration, and on the nature of the counterion, indicating some cation-anion interactions. Measurements on Mg²⁺—phosphonoacetic acid mixtures in aqueous solutions gave strong indications of complexation. Only inconclusive evidence was obtained on the complexation of Mg²⁺ by macro-bicyclic cryptand C211 in methanol solutions, and no evidence of complexation was obtained with macrocycle 12-crown-4 in dimethylformamide solutions.     

杯[4]冠醚对过渡金属离子的液膜传输行为

藉杯芳烃衍生物的识别作用可以实现对金属离子的选择性液膜传输,本文研究了4种新型杯[4]冠醚对5种过渡金属离子（Cu^2 ,Fe^3 ,Co^2 ,Ni^2 ,Zn^2 ）的液膜传输行为,发现其中酯型杯[4]冠醚（Ⅲ）对Cu^2 有优良的传输效能,并考察考察了各种因素（包括源相和受相酸度、离子载休Ⅲ的浓度、时间及温度等）的影响,指出载体Ⅲ对C ^2 的传输为H^ 交换机理,并对该过程进行了初步解释。     

Unprecedented Cyclizations of Calix[4]arenes with Glycols under the Mitsunobu Protocol. Part 4. An Expedient Route to Thiacalix[4](Aza and Thia)Crowns

The Mitsunobu cyclization of p-t-butylthiacalix[4]arene with glycols was expanded to oligoethylene glycol analogues composed of O, S and N atoms in the chain. In this way a number of 1,3-thiacalix[4]monocrowns have been synthesized, offering simple and general access to a large variety of crowned thiacalixarenes. The binding properties of some ligands towards transition metal cations have been studied by ¹H NMR, UV/Vis spectroscopic and potentiometric methods.     

Spectroscopic Study of Some Alkali and Alkaline Earth Complexes with Benzo Crown Ethers in Ethanol Solution

The interaction between Na⁺, K⁺, Mg²⁺ and Ca²⁺ ions and benzo crown ethers B15C5, DB18C6, DB21C7, DB24C8 and DB30C10 in ethanol solution has been studied spectrophotometrically at 25°C. The formation constants for 1:1 complexes were determined by computer fitting of the resulting UV-absorbance-mole ratio data. In the case of all crown ethers used, K⁺ ion was found to form the most stable complexes. The observed selectivities of different benzo crowns for the cations used are discussed in terms of the cavity-cation size ratio, number of the donating oxygens participating in the cation binding, conformations of the free and complexed ligands and ionic solvation.     

二氧化硅固载苯并冠醚的合成与性能

3-烯丙基邻苯二酚与氯乙醇反应,得到3-烯丙基-1,2-双羟乙氧基苯,它与二缩三乙二醇双对甲苯磺酸酯反应,得到3-丙烯基苯并18-冠-6。从4-烯丙基邻苯二酚类似地制得4-烯丙基1,2-双羟乙氧基苯。它与1,2-双羟乙氧基苯双对甲苯磺酸酯反应,合成了4-丙烯基二苯并-18-冠-6。二种丙烯基取代冠醚与三氯硅烷反应,以二氧化硅固载化,得到二氧化硅固载苯并冠醚,它们皆可与铂形成配合物,是一类新型烯烃硅氢化催化剂。     

Syntheses and Metal-ion Binding Properties of Calix[4]arene Derivatives Containing Soft Donor Atoms: Highly Selective Extraction Reagents for Ag+

A series of calix[4]arene derivatives containing N or S atoms atthe lower rim were synthesized by etherification of OH groups and their metal-ion extraction abilities were studied. The extraction selectivity for Ag⁺ over other ions with these novel receptors was outstanding. Among these ligands, calix[4]arene podand, which possessed two linear ligands, has shown better binding ability with Ag⁺ than calix[4]crowns.