- Mechanically linked polyrotaxanes: A stepwise approach
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A new synthetic approach for the preparation of mechanically linked polyrotaxanes was developed. Two variations of rotaxane monomers were synthesized, based on diphenylmethane and tetraphenylmethane blocking groups. Both rotaxanes bear a protected phenol
- Werts, Michel P.L.,Van Den Boogaard, Maarten,Tsivgoulis, Gerasimos M.,Hadziioannou, George
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p. 7004 - 7013
(2007/10/03)
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- Structure and Photophysical Properties of Constrained Donor-Acceptor [2]Catenanes Bearing an Appended Secondary Donor
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Procedures are reported for the synthesis of N N'-bipyridinium-based [2]catenanes bearing appended ester (1), carboxylic acid (2) or 2,5-(dimethoxy)benzyl benzoate (3) moieties as integral parts of the cationic cyclophane. Associative interaction between the donor-acceptor units that comprise the two interlocked rings of the [2]catenanes causes formation of a charge-transfer (CT) absorption band for which the maximum is slightly sensitive to structural variations. Illumination into this CT absorption band with short laser pulse generates a compact radical ion pair (RIP), which for 1 and 2 survives for ca. 50 ps before undergoing charge recombination to restore the ground state. The rate of charge recombination can be rationalized in terms of the amount of energy that has to be dissipated among skeletal vibrational modes and is slower than that found for closely-related rotaxanes. In contrast, the charge recombination dynamics within the RIP formed from catenane 3, are more complex and it is suggested that external dimethoxybenzene donor is involved in the overall process.
- Benniston, Andrew C.,Gardner, Struan,Farrugia, Louis J.,Harriman, Anthony
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p. 901 - 930
(2007/10/03)
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- Simple mechanical molecular and supramolecular machines: Photochemical and electrochemical control of switching processes
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Photochemical control of a self-assembled supramolecular 1:1 pseudorotaxane (formed between a tetracationic cyclophane, namely the tetrachloride salt of cyclobis(paraquat-p-phenylene), and 1,5-bis[2-(2-(2-hydroxy)ethoxy)ethoxy]naphthalene has been achieve
- Ashton, Peter R.,Ballardini, Roberto,Balzani, Vincenzo,Boyd, Sue E.,Credi, Alberto,Gandolfi, Maria T.,Gomez-Lopez, Marcos,Iqbal, Sayeedha,Philp, Douglas,Preece, Jon A.,Prodi, Luca,Ricketts, Howard G.,Stoddart, J. Fraser,Tolley, Malcolm S.,Venturi, Margherita,White, Andrew J. P.,Williams, David J.
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p. 152 - 170
(2007/10/03)
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