The 1,3-distal cone-calix[4]arene dialdehyde 1 undergoes Cannizzaro disproportionation in the presence of strong base, but its 1,2-vicinal regioisomer 3 and the analogous monoaldehyde 2 are unreactive under the same conditions. The high intramolecular reactivity of the 1,3-distal regioisomer 1 is measured and discussed in terms of Effective Molarity (EM).

Single Langmuir-Blodgett (LB) bilayers derived from calix[n]arene-based surfactants (n = 4, 5 and 6) and poly(acrylic acid) (PAA) exhibit exceptional H(2)/CO(2) permeation selectivities. Evidence for the importance of ionic crosslinking and self-healing processes is presented.

This study aims to investigate the application of two calix[4]arene derivatives named 5,11,17,23-tetra-(t-butyl)-25,26,27,28-tetrahydroxycalix[4]arene (TBCA) and 5,11,17,23-tetra-(t-butyl)-26,27,28-tribenzoyloxycalix[4]arene (TBMTCA) as adsorbents Pb(II) from aqueous solution in a batch system. Adsorption was carried out by varying pH solution, exposure time, concentration. The kinetics evaluat...

Varied temperature sublimation of calix[5]arene results in the formation of two distinctly different crystal structures or polymorphs alpha and beta, the latter of which is based on both 'self-included' and 'back-to-back' helical arrangements of the molecule, while also being active towards CO2 sorption at room temperature and 1 atmosphere pressure.

A direct mercuration reaction combined with a subsequent Pd-catalyzed arylation was used to introduce the aryl moiety into the meta position of the calix[4]arene skeleton. The application of organomercurial intermediates thus allows the straightforward formation of meta-aryl-substituted derivatives representing a unique substitution pattern in calixarene chemistry.

Paramagnetic liposomes used as contrast agents in magnetic resonance imaging (MRI) often suffer from low efficacies because of slow water diffusion through the membrane. We present an approach to overcome this limitation by incorporation of a calix[4]arene based agent that expresses the chelates towards the bulk water.

A novel coordination nanocage was obtained with in situ-generated tetrazole ligands from the cobalt-thiacalix[4]arene system. Four in situ-generated 1,3-bis(2H-tetrazol-5-yl)benzene ligands bolster eight Co4-calix shuttle-cock-like secondary building units (SBUs) into a hollow tetragonal prism with a high surface area. The unprecedented {Co32} nanocage presents the highest nuclearity example.

The chemistry of calixarenes has received increasing attention in the field of Supramolecular Chemistry, as this class of molecules offers a suitable platform for the synthesis of receptors for anions, cations and neutral molecules. Their structures allow acylation and alkylaton reactions of the phenolic groups. The conformation and degree of substitution of acylated products are related to the...

Abstract The mechanism of electrochemical reduction a series six cone ‐calix[4]arene‐bis‐nosylates (4‐nitrophenylsulfonate aryl esters) was investigated on mercury electrodes using DC‐polarography and cyclic voltammetry (CV) combined with in situ electron paramagnetic resonance (EPR)‐spectroelectrochemistry aprotic dimethylformamide. Model compounds – expected fragments products ‐ were studied ...

The 1, 3-bis(trimethyl silyl)ether of p-tert-butyl calix[4]arene, Rt-Bu)Ca1ixTMS21112, has beensynthesized and used as a dianionic ligand for "Sn". The complex of [(t-Bu)Ca1ixTMS2]Snexhibits exo and endo isomerism. The structural properties of [(Rp)Ca1ixTMS2]Sn, (Rpara= H,CH3, t-Bu) and the inter conversion of exoendo isomers were investigated by using of SCF-MOPM3 method.