Reversible helix–random coil transition of poly(m-phenylenediethynylene) by a rotaxane switch

Abstract

Pendant rotaxane switch-tethering poly(m-phenylene diethynylene) was synthesized by the polyoxidative coupling of a rotaxane containing an axle-terminal m-diethynylbenzene group and an optically active crown ether. The reversible helix-random coil transition of the polymer was successfully performed by the positional switching of the rotaxane wheel.

Chiroptical inversion of a planar chiral redox-switchable rotaxane

“…Comparable rotaxanes also showed this behaviour on the same position. 27,28 HR-ESI mass and tandem MS experiments support the interlocked architecture ( Fig. S1 †).…”

“…13 Chiral rotaxanes may be chiral from inclusion of classical stereogenic elements or by virtue of being mechanically planar chiral. Since then, several examples followed, [14][15][16][17][18][19][20][21][22][23][24][25] in which the mechanically interlocked structure was used to induce directionality in polymers, [26][27][28] for sensing, [29][30][31] and to act as an enantioselective catalyst. 32 Today, sophisticated synthetic protocols allow an efficient enantioselective synthesis.…”

Dondorff Rings: Synthesis, Isolation, and Properties of 60°‐Directed Bisterpyridine‐Based Folded Tetramers

“…These intricate ensembles have revolutionized the field of supramolecular chemistry. The work of Lehn,5, 6 Stoddart,7, 8 Schmittel,9–11 and others12–22 continues to introduce increased complexity into multicomponent systems; however, most self‐assembly techniques rely on the target compound having the most thermodynamic stability leading to the desired structure. Less stable products must be synthesized by kinetic control, utilizing structural factors such as steric or ionic effects to achieve the desired macromolecular targets.…”

A novel switchable [2]rotaxane driven by light energy with Rhodamine B as a stopper

“…These changes were due to the strong hydrogen bond between DB24C8 and the secondary ammonium salt and offer additional proof of this synthetic method's ability to synthesize [2]rotaxane. Moreover, all of the proton peaks belonging to the macrocyclic DB24C8 (21,22,23,24) appeared in Fig. 2d at 4.151, 3.912, 3.835 and 6.884 ppm, respectively, and moved downfield significantly (Dd¼0.173, 0.199, 0.226, and 0.070 ppm, respectively) because the macrocyclic ring was interlocked on the dumbbell of 7 to form [2]rotaxane.…”