An Efficient, Redox-Enhanced Pair of Hydrogen-Bond Tweezers for Chloride Anion Recognition, a Key Synthon in the Construction of a Novel Type of Organic Metal based on the Secondary Amide-Functionaliz
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- 作者：Karine Heuzé ; Cé ; cile Mé ; ziè ; re ; Marc Fourmigué ; Patrick Batail ; Claude Coulon ; Enric Canadell ; Pascale Auban-Senzier ; and Denis Jé ; rome
- 刊名：Chemistry of Materials
- 出版年：2000
- 出版时间：July 2000
- 年：2000
- 卷：12
- 期：7
- 页码：1898 - 1904
- 全文大小：100K
- 年卷期：v.12,no.7(July 2000)
- ISSN：1520-5002
文摘
Electrocrystallization of 1,1,2-trichloroethane solutions of the redox-active secondary amide,3-methylamido-3',4'-ethylenedithiotetrathiafulvalene (EDT-TTF-CONHMe 1) in the presenceof n-Bu4NF supported on silica gel afforded a mixed-valence chloride salt, formulated (1)2[Cl·H2O] from elemental analysis and X-ray crystal structure resolution. The chloride anionand water molecule are disordered on the same site, and coordinated to the 
-donor moleculeby two strong hydrogen bonds involving the amidic N-H and the aromatic C-H group orthoto the amide, thereby qualifying a robust pair of tweezers-like cyclic motif. This efficientanion recognition effect is also observed in solution, as demonstrated by 1H NMR downfieldshifts of both the N-H and C-H hydrogen atom resonances, as well as by a cathodic shiftof the oxidation potential of 1 upon Cl- complexation, establishing that the actualelectrocrystallized species is a solvated anionic chloride complex [(1·Cl-)(H2O)n] rather thanthe free amide. (1)2[Cl·H2O] adopts a layered 
' '-type structure with segregation of thehydrophobic (EDT-TTF) and hydrophilic (amide, Cl-, H2O) fragments. The HOMO-HOMOintermolecular interaction energies for the donor layers are large and the Fermi surfaceexhibits a pronounced two-dimensional character. The EPR Dysonian line observed below120 K indicates an highly conducting system, confirmed by high room-temperatureconductivity of 120 S cm-1 and metallic behavior down to 0.47 K, with a 167-fold increaseof the conductivity, but no indication however of a transition to a superconducting state, alikely consequence of the Cl-/H2O disorder.
-donor moleculeby two strong hydrogen bonds involving the amidic N-H and the aromatic C-H group orthoto the amide, thereby qualifying a robust pair of tweezers-like cyclic motif. This efficientanion recognition effect is also observed in solution, as demonstrated by 1H NMR downfieldshifts of both the N-H and C-H hydrogen atom resonances, as well as by a cathodic shiftof the oxidation potential of 1 upon Cl- complexation, establishing that the actualelectrocrystallized species is a solvated anionic chloride complex [(1·Cl-)(H2O)n] rather thanthe free amide. (1)2[Cl·H2O] adopts a layered ' '-type structure with segregation of thehydrophobic (EDT-TTF) and hydrophilic (amide, Cl-, H2O) fragments. The HOMO-HOMOintermolecular interaction energies for the donor layers are large and the Fermi surfaceexhibits a pronounced two-dimensional character. The EPR Dysonian line observed below120 K indicates an highly conducting system, confirmed by high room-temperatureconductivity of 120 S cm-1 and metallic behavior down to 0.47 K, with a 167-fold increaseof the conductivity, but no indication however of a transition to a superconducting state, alikely consequence of the Cl-/H2O disorder.