Giant regular polyhedra from calixarene carboxylates and uranyl

Abstract

Self-assembly of large multi-component systems is a common strategy for the bottom-up construction of discrete, well-defined, nanoscopic-sized cages. Icosahedral or pseudospherical viral capsids, built up from hundreds of identical proteins, constitute typical examples of the complexity attained by biological self-assembly. Chemical versions of the so-called 5 Platonic regular or 13 Archimedean semi-regular polyhedra are usually assembled combining molecular platforms with metals with commensurate coordination spheres. Here we report novel, self-assembled cages, using the conical-shaped carboxylic acid derivatives of calix[4]arene and calix[5]arene as ligands, and the uranyl cation UO22+ as a metallic counterpart, which coordinates with three carboxylates at the equatorial plane, giving rise to hexagonal bipyramidal architectures. As a result, octahedral and icosahedral anionic metallocages of nanoscopic dimensions are formed with an unusually small number of components.

Solvent‐Dependent Self‐Assembly Behaviour and Speciation Control of Pd6L8 Metallo‐supramolecular Cages

“…Other types of molecular hosts have also been employed to this effect, most particularly from the calixarene family. [5] Cyclotriveratrylene is a relatively rigid and pyramidal-shaped host with an open upper rim. [6] Both CTV and its chiral analogue cyclotriguaiacylene (CTG) can be converted into extended-armed host molecules through upper rim functionalisation.…”

Amphiphilic p‐tert‐butylthiacalix[4]arenes containing quaternary ammonium groups: from small molecules toward water‐soluble nanoscale associates

“…Self‐association of p‐tert ‐butylthiacalix[4]arenes 1 , 2 , 3 , 4 , 5 and aggregation of the compounds 1 , 2 , 3 , 4 , 5 with amino acids were studied in water (Table ). It should be mentioned that according to the literature, the NO 3 − anions of p‐tert ‐butylthiacalix[4]arenes do not play a role in the self‐assembly process.…”

Pesticides Removal by Filtration over Cactus Pear Leaves: A Cheap and Natural Method for Small‐Scale Water Purification in Semi‐Arid Regions

“…Uran ist eher selten in supramolekularen Systemen zu finden. Die Fähigkeit des Uranyl(VI)‐Kations UO22+, drei Carboxylatliganden in der äquatorialen Ebene zu koordinieren, nutzten Mendoza et al, um große Gebilde wie den in Abbildung 25a gezeigten calixarenbasierten, sphärischen Käfig zu synthetisieren 43…”