Calixarenes as hosts

Complexation of Cations and C o as Guests with Crown Ethers, Ciyptands, and Calixarenes as Hosts... 

As part of an ongoing research programme aimed at the construction of redox-active calixarene-based host molecules designed to sense neutral... 

CONTENTS Preface. George W. Gokel. Cryptophanes Receptors for Tetrahedral Molecules, Andre Collett, Jean-Pierre Dutasta and Benedict Lozach. Inclusion Polymerization in Steroidal Canal Complexes, Kiichi Takemoto, Mikiji Miyata. Functionalized Tetraazamacrocycles Ligands with Many Aspects, Thomas A. Kaden. Calixarenes as the Third Supramolecular Host, Seiji Shinkai, Kyushu University, Japan. Fluorescent Chemosensors for Metal and Non-Metal Ions in Aqueous Solutions Based on the Chief Paradigm, Anthony W. Czamik. Index. 

Hosomi-Sakurai reaction, allylsilations, 9, 305 Host complexes calixarenes as, 12, 799 crown-ethers as, 12, 813... 

The calixarenes are extremely versatile host frameworks and, depending on their degree of functionalisation, may act as hosts for cations, anions and neutral molecules, as we will see in Chapters 4 and 5. 

As hosts for cations, the phenolic oxygen atoms at the calixarene lower rim (Figure 3.81) have the potential to act in a similar way to the anisole residues of the spherands, either in the original hydroxyl form or as alkyl ether derivatives. This kind of behaviour has been observed for the methyl ether of the parent /j-f-butylcalix[4] arene (compound 3.121) upon reaction with a mixture of sodium benzoate, one... 

Much interest has centred on the branch of cyclophanes known as calixarenes. They are polyphenol systems that can act as hosts in the formation of inclusion compounds, where a small guest molecule resides completely in a cavity within a single host they are cone-shaped cavitands . Several accounts have appeared of their history. The discovery by Baeyer of a formaldehyde/phenol resin led to Bakelite and to the work of A. Zincke and E. Ziegler, who gave to the first oligomer a tetrameric structure of a calix[4]arene. Later syntheses by Gutsche (1978) led to calixarenes with 4, 6 or 8 phenol residues.107-109... 

The area covered is very widespread and the role of the calixarene molecules reach from a simple platform or skeleton on which to assemble chiral centers to an inherent part of the chiral structure. Biologically active molecules or derivatives are involved as well as artificial ligands and their metal complexes. Chiral calixarenes have been used as stationary phases in analytical separations or as host molecules in sensors. Basic properties of calixarenes, such as their conformational stabilities, have been studied with chiral derivatives as well as more... 

P-5 A phosphinic calixarene is complexed to four Ag(I)Q molecules and one additional chloride ion to give an anion (161) that can act as host for alkali metal cations, Hg(II) and Pb(II)235 236. 

The synthesis and nomenclature of calixarenes such as 3.118 has already been in introduced (Section 3.14 - For an introduction to calixarenes and the history of their development see Box 3.4) in the context of their widespread applications as hosts for cations, generally binding to metals through... 

Calixarenes and Resorcinarenes 12.16.1.3.1 Introduction to calixarenes as supramolecular hosts... 

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