A Chronology of Cavitands

Hydrophobic and Metal-Coordinated Confinement Effects Trigger Recognition and Selectivity

“…Cavitands are container host molecules with an open end and movable walls that allow uptake and release of guests. Since their introduction by Cram , and Dalcanale, cavitands are widely used in studies of molecular recognition and confinement. , Many structural variants have been reported on the basis of the resorcinarene platform and with a wide variety of aromatic panels or “walls”. − They exist in two different shapes: the receptive “vase” shape and unreceptive “kite” (or velcrand) shape . Both shapes often exist in dimeric forms known as capsules and velcrands, respectively.…”

“…The guest molecules fill the space of the cavities and solvate the interior surfaces of the hosts. Additional functional groups that create further possibilities for selectivity in guest recognition can be introduced on the upper rim …”

Recent Advances in the Applications of Water‐soluble Resorcinarene‐based Deep Cavitands

“…Many structural variants of cavitands have been reported that are based on the resorcinarene platform, with additional functional groups on the upper rim for further possibilities in selective guest recognition. [32] We recently expanded the applications of metal complexation by using 2‐aminobenzimidazoles for the walls of the cavitand (Figure 8 A). [33] The reorganized shape of the space in metallo‐cavitand H7−2Pd showed a good shape and size selectivity for o ‐difluorobenzene over its isomers.…”

Bamboo-like Chained Cavities and Other Halogen-Bonded Complexes from Tetrahaloethynyl Cavitands with Simple Ditopic Halogen Bond Acceptors

“…Resorcinarenes, − their salts, − and resorcinarene cavitands − ,,− are well-studied families of macrocyclic receptors. Resorcinarenes are particularly useful due to their ease of preparation, simplicity of functionalization, and versatility as hosts for a wide variety of guests. − The known resorcinarene capsules formed through HBs, metal–ligand coordination bonds, and dynamic covalent bonds have recently been reviewed by Kobayashi and Yamanaka .…”

“…Our previous crystallographic analysis , showed that cavitands 1 – 3 , with four haloethynyl XB donor groups have two distinct XB acceptor sites: the eight ether oxygens at the cavitand bridges, and the four ethynyl (−CC−) groups on the upper rim. In addition to these XB donor and acceptor sites, the cavitand has a cavity appropriate for small guest encapsulation. − ,, All these features combine to allow for a multitude of noncovalent interactions, especially the strong X···N XBs, but also the weaker X···O and X··· π XBs and the CH···π and π···π interactions (Figure ). , …”