Redox-Induced Ring Shuttling and Evidence for Folded Structures in Long and Flexible Two-Station Rotaxanes

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Title:Redox-Induced Ring Shuttling and Evidence for Folded Structures in Long and Flexible Two-Station Rotaxanes
Creators:
Yamamoto, Tohru
Tseng, Hsian-Rong
Stoddart, J. Fraser
Balzani, Vincenzo
Credi, Alberto
Marchioni, Filippo
Venturi, Margherita
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 68, 8, pp. 1488-1514
Uncontrolled Keywords:Photochemistry, Tetrathiafulvalene, Molecular shuttles, Cyclophanes, Bipyridinium ions, Electrochemistry, Rotaxanes, Charge-transfer interactions

Abstract

Two dumbbell-shaped components with tetraarylmethane-type stoppers - one hydrophobic and one hydrophilic - and a rod-like section containing a tetrathiafulvalene (TTF) unit and a 1,5-dioxynaphthalene (DNP) moiety as electron-donating units, and their [2]rotaxanes, incorporating the cyclobis(paraquat-<i>p</i>-phenylene) (CBPQT<sup>4+</sup>) cyclophane as their electron-accepting ring component, have been synthesized, the latter using template-directed protocols. The two amphiphilic [2]rotaxanes, which differ from each other only in the lengths of the polyether chains associated with their hydrophilic stoppers, were designed in order (i) to have them exhibit enhanced amphiphilicities and, by altering the lengths of polyether chains, (ii) to improve the qualities of their Langmuir-Blodgett films, and by removing the phenolic residues, (iii) to increase the oxidative stabilities of these switchable molecules, and so extend the lifetimes of electronic devices fabricated from amphiphilic hysteretic molecular switches of this type. UV-VIS absorption and<sup> 1</sup>H NMR spectra, as well as electrochemical measurements, show that both [2]rotaxanes exist to all intents and purposes in solution as the translational isomer in which the CBPQT<sup>4+</sup> cyclophane surrounds the TTF unit. Evidence has also been obtained for the presence in solution of folded conformations of these [2]rotaxanes. While ox/red stimulation of the TTF unit causes shuttling of the CBPQT<sup>4+</sup> cyclophane between the TTF and DNP stations, reduction of CBPQT<sup>4+ </sup>causes unfolding of the [2]rotaxane molecules. <p>

Title:Redox-Induced Ring Shuttling and Evidence for Folded Structures in Long and Flexible Two-Station Rotaxanes
Creators:
Yamamoto, Tohru
Tseng, Hsian-Rong
Stoddart, J. Fraser
Balzani, Vincenzo
Credi, Alberto
Marchioni, Filippo
Venturi, Margherita
Uncontrolled Keywords:Photochemistry, Tetrathiafulvalene, Molecular shuttles, Cyclophanes, Bipyridinium ions, Electrochemistry, Rotaxanes, Charge-transfer interactions
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:68
Number:8
Page Range:pp. 1488-1514
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc20031488UNSPECIFIED
ID Code:2133
Item Type:Article
Deposited On:06 Feb 2009 17:15
Last Modified:06 Feb 2009 16:15

Citation

Yamamoto, Tohru; Tseng, Hsian-Rong; Stoddart, J. Fraser; Balzani, Vincenzo; Credi, Alberto; Marchioni, Filippo; Venturi, Margherita (2003) Redox-Induced Ring Shuttling and Evidence for Folded Structures in Long and Flexible Two-Station Rotaxanes. Collection of Czechoslovak Chemical Communications, 68 (8). pp. 1488-1514. ISSN 0010-0765

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