Stepwise Motion in a Multivalent [2](3)Catenane

Abstract

The motions of biomolecular machines are usually multistep processes, and are involved in a series of conformational changes. In this paper, a novel triply interlocked [2](3)catenane composed of a tris(crown ether) host eTC and a circular ditopic guest with three dibenzyl ammonium (DBA) sites and three N-methyltriazolium (MTA) sites was reported. Due to the multivalency nature of the catenane, the acid-base triggered motion was performed by a stepwise manner. The coconformations of the four related stable states have been directly identified and quantified which confirmed the multistep process. In order to quantify the dynamics with environmental acidity changes, the values of the three levels of dissociation constant pKa have been determined. The special interlocked topology of the [2](3)catenane also endows the motion of each crown ether ring in the host with unexpected selectivity for the MTA sites. This study provides clues to comprehend the underlying motion mechanism of intricate biological molecular machines, and further design artificial molecular machine with excellent mechanochemistry properties.

Electrospun nanofibrous membrane of porous fluorine-containing triptycene-based polyimides for oil/water separation

“…Triptycene and its derivatives have attractive applications in supramolecular chemistry [26][27][28][29] and microporous polymers [30][31][32][33] because of their 3D rigid structures. More and more triptycene based PIMs [34][35][36] are being reported in gases separation, but not in oil/water separation.…”

One-pot synthesis of a [c2]daisy-chain-containing hetero[4]rotaxane via a self-sorting strategy

“…As a modification platform for functional groups, the structural complexity of MIMs significantly provides infinite possibilities in designing novel functional molecular machines. 3 Hence, the construction and efficient synthesis of MIMs with high structural complexity have been greatly attractive but challenging. 4 Recently, much attention has been focused on the topological, 3 a interpenetrating, 5 knotted 6 structures of MIMs with high structural complexity.…”

Wholly Synthetic Molecular Machines

“…[66][67][68][69] For example, dibenzo [24]crown-8 (DB24C8) forms strong hydrogen bonds with secondary dialkylammonium ions, [70] leading to the formation of an interpenetrating 1:1c omplex which dissociatesa ss oon as the -CH 2 NH 2 + CH 2 -c enter is deprotonated (Figure 3a). [66][67][68][69] For example, dibenzo [24]crown-8 (DB24C8) forms strong hydrogen bonds with secondary dialkylammonium ions, [70] leading to the formation of an interpenetrating 1:1c omplex which dissociatesa ss oon as the -CH 2 NH 2 + CH 2 -c enter is deprotonated (Figure 3a).…”

“…Initially,c hemical fuels provedt ob ea na ttractive source of energy because of their ready accessibility based on am ultitude of reversible chemical reactions, amongst which the acidbase ones are the most common. [66][67][68][69] For example, dibenzo [24]crown-8 (DB24C8) forms strong hydrogen bonds with secondary dialkylammonium ions, [70] leading to the formation of an interpenetrating 1:1c omplex which dissociatesa ss oon as the -CH 2 NH 2 + CH 2 -c enter is deprotonated ( Figure 3a). While www.chemphyschem.org living organismsh ave evolveds ophisticated circulatory systems to transport chemicalf uels from one place to another in order to eliminate chemical waste, chemists have yet to address the challenge of managing simultaneously fuel delivery and waste transport in artificial systems.…”