Themed collection Mechanical Bond and Dynamic Covalent Bond

Jishan Wu and Fraser Stoddart introduce the Materials Chemistry Frontiers themed collection on mechanical bonds and dynamic covalent bonds.

This review describes recent advances and scientific challenges in the area of post-synthetic methodologies to tailor the functionalities and properties of COFs.

This review summarizes pH-controlled mechanical motions including translocation in rotaxanes, circumrotation in catenanes and other motions in more sophisticated mechanomolecules.

Dynamic covalent bonds by stable radical species are ideal platforms for simple, facile, and clean rearrangements of chemical bonds without the need for catalysts and the formation of byproducts.

This review summarizes recent advances in dynamic pseudorotaxane crystals with response to external stimuli, such as light and/or heat.

This research revealed a distinct manipulation manner of a molecular emissive system, that is an orthogonally tunable dual-pathway mode, enabling a multi-color fluorescent system covering the whole white-light region.

Mechanofluorescent polymer/silsesquioxane composites were prepared by introducing tetraarylsuccinonitrile derivatives, which are mechanically cleaved to generate the corresponding pink carbon-centred radicals that exhibit yellow fluorescence.

Dramatic differences were disclosed in the supramolecular polymerizability of dioxynaphthalene motif bridged bifunctional ureidopyrimidinone isomers and their different host–guest behaviors with a blue-box.

A push–pull perylene dye shows solvent dependent diradical character and negative solvatochromism.

Effective linear-to-cyclic polymer topology transformation of poly(methyl acrylate) (PMA) utilizing the translocation property of the introduced [1]rotaxane unit.

Kinetically and thermodynamically favored [2]rotaxanes, with an axle component positioned within a large and small ring, respectively, were provided by bridging of a [2]pseudorotaxane formed from an unsymmetric mono-crown ether and the ammonium salt.

Rotaxanes were studied for their selective sensing to trivalent metal ions and Au³⁺ with turn-on fluorescence and for bioimaging.

An efficient strategy to increase the photosensitivity of a fast photochromic molecule is demonstrated by introducing aryl groups as sensitizers.

Facile synthesis of diverse rotaxanes was successfully realized through a simple and efficient supramolecular transformation strategy.

Folic acid conjugated hollow silica nanocarriers loaded with zinc phthalocyanine are employed for selective photodynamic therapy of cutaneous squamous cell carcinoma.