Spectroscopic study on the complex formation of chromogenic bridged calixarenes with aliphatic amines

The complex formation between chromogenic capped calix 4 arene derivatives comprising indophenol indicator group(s), and aliphatic amines has been studied by UV/Vis spectroscopy. The equilibrium constants have been determined in ethanol, and—for one ligand—also in dimethylsulfoxide. The results have been interpreted in terms of various types of host–guest interactions and of steric effects.     

Synthesis, Characterisation and UV-Vis Properties of Azocalix[4]crowns

This article describes the synthesis, structure andUV properties of azocalixcrowns in which the photoresponsivetrans-cis azo benzene unit has been introduced in the glycolicchains of the calix[4]crowns. The synthesis proceeded via the selective-1,3O-dialkylation of calix[4]arene with glycolic chains terminated bynitrophenyl residues. After reduction of thenitro groups into amino functions,intramolecular oxidative coupling produced thecapping of the calixarene. Thesynthetic approaches and the cis-transstructure of these new ligandsare discussed and full details on synthesesand structural data are given. Apreliminary example of cesium complexation byone of the ligands is proposed.     

Hetero-calix[4]pyrroles: incorporation of furans, thiophenes, thiazoles or fluorenes as a part of the macrocycle

Furans, thiazoles, fluorene or thiophene incorporated calix[4]pyrrole analogues were synthesized and characterized. The synthesis was achieved by utilization of various building blocks such as 7, 13, 14, 18 and 21. Acid catalyzed condensation of those building blocks with acetone or meso-disubstituted dipyrromethanes afforded desired macrocycles.     

Cation recognition by new diester- and diamide-calix[4]arenediquinones and a diamide-benzo-15-crown-5-calix[4]arene

The synthesis, metal, ammonium and alkyl ammonium cation coordination chemistry and electrochemical recognition studies of new diester-and diamide-calix[4]arenediquinone receptors are described. In addition the synthesis and coordination properties of a novel diamide benzo-15-crown-5-calix[4]arene molecule is reported.This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes.     

Calix[4]arene-based ditopic receptor for dicarboxylates

Shape-selective recognition for the dicarboxylates in DMSO can be attained by a new calix[4]arene-based receptor 1 having two urea groups. Biologically active chorismate selectively bound in 1 over its dehydrated derivative. Molecular mechanics calculations gave a plausible explanation for the selective binding.     

Synthesis and structure characterization of a novel series of N-alkylphthalimidylaminocarbonylmethoxylcalix [4] arenes

A novel series of N-alkylphthalimidylaminocarbonylmethoxylcalix[4]arenes with the reaction between 4-(N-bromoacetyla- mino)-phthalimide derivatives and calix[4]arene has been synthesized and structurally characterized by IR,~1HNMR and MS.From their analysis data,it was found that compounds 7a-7d adopted a cone conformation.     

Synthesis and amino acid extraction abilities of chiral calix[4]arene triamides containing amino alcohol units

Herein the synthesis and extraction abilities of new d-/l-phenylalaninol substituted p-tert-butylcalix[4]arene triamide derivatives (3 and 4) towards amino acids are reported. These compounds (3 and 4) have been easily synthesized via aminolysis of p-tert-butylcalix[4]arene trimethylester (2) with d-/l-phenylalaninol in methanol-toluen solvent system at one step. The extraction properties of the prepared chiral calix[4]arene triamide derivatives (3 and 4) towards some selected amino acid methylesters are studied by liquid–liquid extraction. Results show that these chiral calix[4]arene triamide derivatives (3 and 4) exhibited a good affinity towards all amino acid species without any remarkably discrimination.     

A selective fluorescent probe for La and Y based on calix[6]arene

A new fluorescent probe based on calix[6]arene functionalized with three naphthoic acid groups was synthesized and showed selective fluorescence enhancement in the presence of La³⁺ and Y³⁺. In addition, the fluorescence enhancement behaviors depended on the pH values of the solution.     

A doubly deprotonated form of calix[6]arene: Crystal and molecular structure of (calix[6]arene-2H)2−·(HNEt 3 + )2

The doubly deprotonated form of calix[6]arene, with two protonated triethylamines as counter-ions, crystallizes in the monoclinic system: space groupP2₁/n,a=8.465(4),b=17.822(8),c=15.182(6) Å,=90.18(4)°,V=2291(2) ų,Z=2. Refinement led to a final conventionalR value of 0.063 for 1046 reflections. The macrocycle conformation is not apinched cone, usual for freeR-calix[6]arene, but a distorted 1,2,3-alternate cone, since the molecule lies on a symmetry center. Furthermore, one of the torsion angles defined by the methylene bridges is near to zero, which is unusual in calixarene structures. Supplementary Data relating to this article (atomic coordinates for hydrogen atoms, anisotropic displacement parameters for oxygen and nitrogen atoms, and observed and calculated structure factors) are deposited with the British Library as Supplementary Publication No. SUP 82182 (7 pages).     

Self-inclusion properties of C60-linked calix[5]arene

C₆₀-linked calix[5]arenes were synthesized and their intramolecular binding properties were investigated. The self-inclusion ratio of the C₆₀ moiety was determined by using UV-vis spectroscopy, and the ratio depends on chain length, temperature, and solvent. Influence of temperature and solvent was explained by the thermodynamic data of the intramolecular complex formation process.