Orientedcalix[6]arene-basedpseudorotaxanes and rotaxanes where the axial component bears a terpyridine ligand as a stopper positioned at the upper rim of the calixarene have been synthesized. The binding ability of the terpyridine unit present in the axle toward zinc salts is affected by the presence of the wheel, its distance with respect to the calix[6]arene upper rim, and the nature of the counterion
the engulfment of a positively charged pyridinium-based guest inside the π-rich cavity of a tris-(N-phenylureido)calix[6]arene host affects its reactivity towards a SN2 reaction. We found that the alkylation of the complexed substrates leads to the formation of pseudorotaxanes and rotaxanes with faster kinetics and higher yields with respect to the standard procedures exploited so far. More importantly
of appropriately designed molecular components, the essential feature of which is their non‐symmetric structure. Specifically they are an axle containing a central electron‐acceptor 4,4′‐bipyridinium core functionalized with a hexanol chain at one side, and a stilbene unit connected through a C6 chain at the other side, and a heteroditopic tris(phenylureido)‐calix[6]arene wheel. In apolar solvents the
Toward Directionally Controlled Molecular Motions and Kinetic Intra- and Intermolecular Self-Sorting: Threading Processes of Nonsymmetric Wheel and Axle Components
kinetic control elements in the self-assembly, thereby dictating which side of the axle pierces the calixarene cavity. Specifically, nonsymmetricaxles with alkyl side chains of different length thread the wheel with the shorter chain. Such a selectivity, in combination with the face-selective threading of viologen-type axles afforded by tris(N-phenylureido)calix[6]arenes, enables a strict directional
Traffic control: By exploiting the interplay of kinetic and thermodynamic effects, the direction of threading/dethreading in a nonsymmetric calixarene wheel can be selected by an appropriate choice of the head group incorporated in the molecular axle (see figure).