Novel Cavity Design Using Calix[n]arene Skeletons:  Toward Molecular Recognition and Metal Binding

Highly constrained guests in complexes of p-tert-butylcalix[6]arene dianion: Pentane-1,5-diammonium and choline

“…Similar examples of chain distortions promoted by complexation can be found in the complexes of p-t-bu-calix [6]arene dianion with hexylammonium [9] and diethylammonium [21], and calix [4]arene derivatives with L-lysine [22], however any eclipsed conformation was reported in these structures. For example, the dihedral angles formed by N + -C 1 -C 2 -C 3 and C 1 -C 2 -C 3 -C 4 for the structure of hexylammonium are 60.9°and 56.3°, with a gauche conformation, but gauche is a local minimum for the plot of energy vs. dihedral angle, and eclipsed is the absolute maximum, so the constraint imposed for pentanediammonium cation is higher than for the previously reported structures.…”

“…Calixarene based receptors are able to interact with organic and inorganic molecules and ions [1], and the interactions with biomolecules [2][3][4] have special interest for sensors and carriers, which increase the solubility of bioactive molecules [5] and allow the controlled delivery of pharmaceuticals.…”

A synthetic icosahedral DNA-based host–cargo complex for functional in vivo imaging

“…In host-guest complexes, two independent entities are supramolecularly associated resulting typically in the entrapment of one of these (guest or cargo) inside the available volume of the other (host) 2 . Host-guest complexes based on synthetic molecular hosts, such as cyclodextrins 3 , calixarenes 4 , cucurbiturils 5 , porphyrins 6 , crown ethers 7 , zeolites 8 and cryptands 9 , form structurally well-defined, synthetic scaffolds. A general strategy to achieve encapsulation within synthetic hosts involves the controlled polymerization of host units resulting in a well-defined cavity within which the guest (cargo) is accommodated and stabilized by molecular recognition 2 .…”

Chloride Selective Calix[4]arene Optical Sensor Combining Urea Functionality with Pyrene Excimer Transduction

“…These supramolecular systems contain a central annulus which is largely aromatic in nature, and are typically substituted on the upper or lower rim of the annulus, resulting in effective host compounds for a wide variety of guests 4,[6][7][8][9] . Calixarenes remain popular building blocks in host-guest chemistry due to the aesthetic and practical preorganised nature of the host cavity for target compounds.…”