Editing Rotaxane (section)

===Molecular machines===
[[Image:Rot.ogg|thumb|Animation of a pH-controlled molecular rotaxane shuttle]]
Rotaxane-based molecular machines have been of initial interest for their potential use in [[molecular electronics]] as logic [[molecular switch]]ing elements and as [[molecular shuttle]]s.<ref>{{cite journal |title= On the Way to Rotaxane-Based Molecular Motors: Studies in Molecular Mobility and Topological Chirality |year= 2001 |journal= [[Acc. Chem. Res.]] |volume= 34 |issue= 6 |pages= 465–476 |doi= 10.1021/ar000179i |pmid= 11412083 |last1= Schalley |first1= C. A. |last2= Beizai |first2= K |last3= Vögtle |first3= F }}</ref><ref>{{cite journal |author= Sauvage, J. P. |title= Transition Metal-Containing Rotaxanes and Catenanes in Motion: Toward Molecular Machines and Motors |year= 1999 |journal= ChemInform |volume= 30 |issue= 4 |pages= no |doi= 10.1002/chin.199904221}}</ref> These [[molecular motor|molecular machines]] are usually based on the movement of the [[macrocycle]] on the dumbbell. The [[macrocycle]] can rotate around the axis of the dumbbell like a wheel and axle or it can slide along its axis from one site to another. Controlling the position of the [[macrocycle]] allows the rotaxane to function as a molecular switch, with each possible location of the macrocycle corresponding to a different state. These rotaxane machines can be manipulated both by chemical <ref>{{cite journal |author1=Coutrot, F. |author2=Busseron, E. |title= A New Glycorotaxane Molecular Machine Based on an Anilinium and a Triazolium Station |year= 2008 |journal= [[Chem. Eur. J.]] |volume= 14 |pages= 4784–4787 |doi= 10.1002/chem.200800480 |pmid= 18409178 |issue= 16}}</ref> and photochemical inputs.<ref>{{cite journal |title= Exercising Demons: A Molecular Information Ratchet |year= 2007 |journal= [[Nature (journal)|Nature]] |volume= 445 |pages= 523–527 |doi= 10.1038/nature05452 |pmid= 17268466 |issue= 7127 |bibcode= 2007Natur.445..523S |last1= Serreli |first1= V |last2= Lee |first2= C. F. |last3= Kay |first3= E. R. |last4= Leigh |first4= D. A. |s2cid= 4314051 }}</ref> Rotaxane based systems have also been shown to function as molecular muscles.<ref>{{cite journal  |title= A New pH-Switchable Dimannosyl [c2]Daisy Chain Molecular Machine |year= 2008 |journal= [[Org. Lett.]] |volume= 10 |pages= 3741–3744 |doi= 10.1021/ol801390h |pmid= 18666774 |issue= 17  |last1= Coutrot |first1= F |last2= Romuald |first2= C |last3= Busseron |first3= E }}</ref><ref>{{cite journal |title= Bridging Rotaxanes' wheels – cyclochiral Bonnanes |year= 2006 |journal= [[Angew. Chem. Int. Ed.]] |volume= 45 |pages= 7296–7299 |doi= 10.1002/anie.200602002 |pmid= 17029314 |issue= 43|last1= Radha Kishan |first1= M |last2= Parham |first2= A |last3= Schelhase |first3= F |last4= Yoneva |first4= A |last5= Silva |first5= G |last6= Chen |first6= X |last7= Okamoto |first7= Y |last8= Vögtle |first8= F }}</ref> In 2009, there was a report of a "domino effect" from one extremity to the other in a Glycorotaxane Molecular Machine. In this case, the <sup>4</sup>''C''<sub>1</sub> or <sup>1</sup>''C''<sub>4</sub> chair-like conformation of the manno[[pyranoside]] stopper can be controlled, depending on the localization of the macrocycle.<ref>{{cite journal |author1=Coutrot, F. |author2=Busseron, E. |title= Controlling the Chair Conformation of a Mannopyranose in a Large-Amplitude [2]Rotaxane Molecular Machine |year= 2009 |journal= [[Chem. Eur. J.]] |volume= 15 |pages= 5186–5190 |doi= 10.1002/chem.200900076 |pmid= 19229918 |issue= 21 }}</ref> In 2012, unique pseudo-macrocycles consisting of double-lasso molecular machines (also called rotamacrocycles) were reported in Chem. Sci. These structures can be tightened or loosened depending on pH. A controllable jump rope movement was also observed in these new molecular machines.<ref>{{cite journal |title= Tightening or loosening a pH-sensitive double-lasso molecular machine readily synthesized from an ends-activated [c2]daisy chain |year= 2012 |journal= [[Chem. Sci.]] |volume= 3 |issue= 6 |pages= 1851–1857 |doi= 10.1039/C2SC20072D|last1= Romuald |first1= Camille |last2= Ardá |first2= Ana |last3= Clavel |first3= Caroline |last4= Jiménez-Barbero |first4= Jesús |last5= Coutrot |first5= Frédéric |hdl= 10261/60415 |hdl-access= free }}</ref>