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Radically enhanced molecular recognition

Trabolsi, Ali and Khashab, Niveen and Fahrenbach, Albert C. and Friedman, Douglas C. and Colvin, Michael T. and Cotí, Karla K. and Benítez, Diego and Tkatchouk, Ekaterina and Olsen, John-Carl and Belowich, Matthew E. and Carmielli, Raanan and Khatib, Hussam A. and Goddard, William A., III and Wasielewski, Michael R. and Stoddart, J. Fraser (2010) Radically enhanced molecular recognition. Nature Chemistry, 2 (1). pp. 42-49. ISSN 1755-4330.

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The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host–guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication.

Item Type:Article
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URLURL TypeDescription ReadCube access
Goddard, William A., III0000-0003-0097-5716
Wasielewski, Michael R.0000-0003-2920-5440
Stoddart, J. Fraser0000-0003-3161-3697
Additional Information:© 2010 Nature Publishing Group. Published online: 17 December 2009. The research was supported by the US Air Force Office of Scientific Research (AFOSR) under their Multidisciplinary University Research Initiative (MURI), award number FA9550-07-1-0534 and by the US National Science Foundation (NSF) under grant numbers CHE-0718928 (M.R.W.) and CHE-0924620 (J.F.S.). M.T.C thanks the Link Foundation for a fellowship. MSC facilities were funded by grants from ARO-DURIP and ONR-DURIP.
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-07-1-0534
Link FoundationUNSPECIFIED
Subject Keywords:Electrochemistry; Organic chemistry; Supramolecular chemistry
Issue or Number:1
Record Number:CaltechAUTHORS:20100115-112029668
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17198
Deposited By: Jason Perez
Deposited On:28 Jan 2010 23:30
Last Modified:09 Mar 2020 13:19

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