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Tetrathiafulvalene Crowns: Redox-Switchable Ligands

2001; Wiley; Volume: 7; Issue: 2 Linguagem: Inglês

10.1002/1521-3765(20010119)7

1521-3765

Franck Le Derf, Miloud Mazari, Nicolas Mercier, Eric Levillain, G. Allard, Amédée Riou, Pascal Richomme, Jan Becher, Javier Garı́n, J. Orduna, N. Gallego-Planas, Alain Gorgues, Marc Sallé,

Solid-state spectroscopy and crystallography

A series of redox-responsive ligands that associate the electroactive tetrathiafulvalene core with polyether subunits of various lengths has been synthesized. X-ray structures are provided for each of the free ligands. The requisite structural criteria for reaching switchable ligands are satisfied for the largest macrocycles, that is, planarity of the 1,1',3,3'-tetrathiafulvalene (TTF) pi system and correctly oriented coordinating atoms. The ability of these ligands to recognize various metal cations as a function of the cavity size has been investigated by various techniques (LSIMS, 1H NMR, and UV/Vis spectroscopy, cyclic voltammetry). These systems exhibit an unprecedented high coordination ability among TTF crown ethers. Their switchable ligating properties have been confirmed by cyclic voltammetry, and metal-cation complexation has been illustrated by X-ray structures of three of the corresponding metal complexes (Pb2+, Sr2+, and Ba2+). Solid-state structures of these complexes display original packing modes with channel-like arrangements.