A pH-sensitive lasso-based rotaxane molecular switch.

Autor: Clavel C; Supramolecular Machines and Architectures Team, Institut des Biomolécules Max Mousseron-UMR CNRS 5247, Université Montpellier 2 et 1, place Eugène Bataillon, case courrier 1706, 34095 Montpellier Cedex 5, France., Romuald C, Brabet E, Coutrot F
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2013 Feb 25; Vol. 19 (9), pp. 2982-9. Date of Electronic Publication: 2013 Jan 23.
DOI: 10.1002/chem.201203597
Abstrakt: The synthesis of a pH-sensitive two-station [1]rotaxane molecular switch by self-entanglement of a non-interlocked hermaphrodite molecule, containing an anilinium and triazole moieties, is reported. The anilinium was chosen as the best template for the macrocycle benzometaphenylene[25]crown-8 (BMP25C8) and allowed the self-entanglement of the molecule. The equilibrium between the hermaphrodite molecule and the pseudo[1]rotaxane was studied by (1)H NMR spectroscopy: the best conditions of self-entanglement were found in the less polar solvent CD(2)Cl(2) and at high dilution. The triazole moiety was then benzylated to afford a benzyltriazolium moiety, which then played a dual role. On one hand, it acts as a bulky gate to trap the BMP25C8, thus to avoid any self-disentanglement of the molecular architecture. On another hand, it acts as a second molecular station for the macrocycle. At acidic pH, the BMP25C8 resides around the best anilinium molecular station, displaying the lasso [1]rotaxane in a loosened conformation. The deprotonation of the anilinium molecular station triggers the shuttling of the BMP25C8 around the triazolium moiety, therefore tightening the lasso.
(Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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