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A series of catenanes have been synthesized through olefin metathesis from a BMP32C10-based cryptand and paraquat guests attached with two terminal alkenes. Distribution of the catenane products can be significantly affected by the linkage length on the paraquat guests. In the presence of BMP32C10-based cryptand, the paraquat salt with a long linkage facilitates intramolecular olefin metathesis to release a [2]catenane as the sole catenation product, while the use of a paraquat salt with a shorter linkage leads to the simultaneous generation of [2]-, [3]-, and [4]-catenanes. [ABSTRACT FROM AUTHOR]

A pillar[5]arene[1]quinone and a difunctionalized pillar[6]arene were synthesized. Their application in host-guest chemistry was investigated by using 1-adamantanylammonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate ( 3), which possesses a weakly coordinating counteranion, as a model guest. These hosts showed different binding affinities for 3 with different association constants. [ABSTRACT FROM AUTHOR]

Cavity-extended pillar[5]arenes containing electron-rich naphthyl groups have been demonstrated to have enhanced binding affinity to linear guests containing electron-deficient pyridinium units. The importance of size effect, charge density, cooperative effect, and C-H ···π interactions were investigated, and these factors play significant roles in the complexation of these host-guest systems. [ABSTRACT FROM AUTHOR]

As a unique property of the interlocked structures, rotaxane allows for intramolecular motions between its wheel and axle components. Introduction of rotaxanes into polymers can endow them with distinctive macroscopic features and outstanding mechanical properties. Here, we prepare a copillar[5]arene with a hydroxyl and an amino‐group on each end, which can spontaneously form a pseudo[1]rotaxane through intramolecular hydrogen bonds. This pseudo[1]rotaxane possesses a releasable extra alkyl chain, which is then incorporated into a linear polyurethane by reacting with a diisocyanate to prepare polyurethane elastomers with spring‐like structures. The results of stress‐strain test and dynamic mechanical analysis all indicate that sliding motions of the axle part on the pseudo[1]rotaxane in the polymer skeleton can greatly dissipate energy, which endows the elastomers with higher toughness and better fatigue resistance. Moreover, the addition of moderate amount of cuprous bromide to form cuprous‐thioether coordination in the polymers can further improve the mechanical properties. [ABSTRACT FROM AUTHOR]