ISSN:
1434-193X
Keywords:
Host-guest chemistry
;
Macrocycles
;
Pseudorotaxanes
;
“Self-complexation”
;
Tetrathiafulvalene
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Two “self-complexing” macrocycles (22ab and 23ab) based on a methylthio-substituted derivative of the electron donor tetrathiafulvalene (TTF) and a cyclic bipyridinium acceptor have been prepared.[1] When “decomplexed” by fractional crystallization, the rigid compound 22b was not able to undergo “recomplexation” to any significant degree, whereas for the more flexible 23b, an equilibrium between “complexed” (23a) and “uncomplexed” (23b) compounds was slowly re-established in solution according to UV/Vis measurements. 23ab was thus seen to behave as a “thermo-switch”, although with a rather slow response. Any complexation between the two separated components, i.e. the cyclic acceptor 3 and the tetrakis(methylthio)tetrathiafulvalene 6, was not observed by 1H-NMR spectroscopy. However, 3 was able to bind unsubstituted TTF (5) in its cavity, albeit with a small association constant of only 60 M-1. Taking advantage of the tetravalency of TTF, we also report the synthesis of a “self-complexing” pyromellitic diimide/TTF macrocycle (33ab). Whereas 22ab and 23ab were prepared employing the concept of template-assisted synthesis,[2] the synthesis of 33ab did not rely on this technique.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
Permalink
