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Tetrathiafulvalene Derivatives (tetrathiafulvalene + derivative)

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Chemistry100%

Selected Abstracts

Arborol-Functionalised Tetrathiafulvalene Derivatives: Synthesis and Thin-Film Formation

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2003
Thierry Le Gall
Abstract The syntheses of a series of novel tetrathiafulvalene derivatives substituted with four side-chains terminating in hydrophilic amidoalcohol (arborol) groups are reported, for example the tetrathiafulvalene derivative 15. Some of these arborol derivatives formed thin films by spin-coating from methanol solution onto solid supports such as glass, ITO-coated glass and gold. The quality of the films improved markedly with an increasing number of alcohol substituents at the periphery of the molecule. Optical absorption spectroscopy showed that oxidative doping of these films could be achieved chemically and electrochemically. The observation of low-energy bands in the UV/Vis absorption spectra (,max = 820 nm tailing to ca. 1300 nm) and the moderate levels of conductivity (,rt , 10,4 S cm,1) in these doped films strongly suggest that a significant degree of supramolecular order is present, with ,-, stacking of the TTF cores. To the best of our knowledge this is the first time that semiconducting behaviour has been achieved in molecular arborol systems that possess an electroactive core unit. This work offers the prospect of using spin-coated films of TTF-arborols as semiconducting charge-transport layers in optoelectronic devices. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Semiconducting Neutral Microstructures Fabricated by Coordinative Self-Assembly of Intramolecular Charge-Transfer Tetrathiafulvalene Derivatives

CHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2009
Yan Geng Dr.
Abstract A new class of tetrathiafulvalene-based microstructures fabricated by coordinative self-assembly has been prepared by a solution process. Upon incorporation of Pb2+ and Zn2+ ions, 1D wirelike microstructures and spherical polymer particles were achieved, respectively (see picture). The neutral coordination polymers are conductive and magnetic at room temperature without external manipulation. A new class of tetrathiafulvalene(TTF)-based microstructures fabricated by coordinative self-assembly has been successfully prepared by a solution process. The morphology of the TTF coordination polymers is readily tuned by the variation of metal ions. Upon incorporation of Pb2+ and Zn2+ ions, one-dimensional (1D) wirelike microstructures and spherical polymer particles were achieved, respectively. These results indicate that the coordinative approach pursued in this work, in which the building blocks of 1 are linked in a coordination polymer chain by association with metal ions, is an efficient and versatile approach to produce more mechanically robust micro- and nanometer-sized coordination polymer materials. More interestingly, the neutral coordination polymers are conductive and magnetic at room temperature without external manipulation. Such conductivity is reminiscent of the behavior of the neutral conductive TTF in single crystals. [source]

Highly Conjugated p -Quinonoid ,-Extended Tetrathiafulvalene Derivatives: A Class of Highly Distorted Electron Donors

CHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2004
Marta C. Díaz
Abstract A new class of ,-extended TTF-type electron donors (11,a,c) has been synthesized by Wittig,Horner olefination of bianthrone (9) with 1,3-dithiole phosphonate esters (10,a,c). In cyclic voltammetry experiments, donors 11,a,c reveal a single, electrochemically irreversible oxidation,yielding the corresponding dicationic products,at relatively low oxidation potentials (,0.7,0.8 V). Theoretical calculations, performed at the DFT level (B3,P86/6-31,G*), predict a highly-folded C2h structure for 11,a. In the ground state, the molecule adopts a double saddle-like conformation to compensate the steric hindrance. The calculations suggest that the intramolecular charge transfer associated with the HOMO,LUMO transition is responsible for an absorption band observed above 400 nm. While the radical cation 11,a.+ retains the folded C2h structure predicted for the neutral molecule as the most stable conformation, the dication 11,a2+ has a fully aromatic D2 structure, formed by an orthogonal 9,9,-bianthryl central unit to which two singly-charged dithiole rings are attached. The drastic conformational changes that compounds 11 undergo upon oxidation account for their electrochemical properties. By means of pulse radiolysis measurements, radical-induced one-electron oxidation of 11,a,c was shown to lead to the radical cation species (11,a,c.+), which were found to disproportionate with generation of the respective dication species (11,a,c2+) and the neutral molecules (11,a,c). Una nueva familia de moléculas dadoras de electrones de tipo TTF , -extendido, altamente conjugadas, (11,a,c) se han sintetizado mediante la reacción de olefinación de Wittig,Horner de la biantrona (9) con fosfonatos de 1,3-ditiol (10,a,c). En los experimentos de voltamperometría cíclica, los dadores 11,a,c muestran una única onda de oxidación electroquímicamente irreversible,dando lugar a los productos dicatiónicos,a potenciales relativamente bajos (,0.7,0.8 V). Cálculos teóricos, llevados a cabo a nivel DFT (B3,P86/6-31,G*), predicen una estructuraC2haltamente distorsionada para 11,a. La molécula adopta una conformación en forma de doble mariposa para aliviar el impedimento estérico. Los cálculos sugieren que la transferencia de carga intramolecular asociada a la transición HOMO,LUMO es responsable de la banda de absorción observada por encima de 400 nm en el espectro electrónico. El catión radical 11,a.+retiene la estructura C2hplegada predicha para la molécula neutra como la conformación más estable. Por el contrario, el dicatión 11,a2+muestra una estructuraD2totalmente aromática,formada por una unidad central de 9,9,-biantrilo ortogonal, unida a los anillos cargados de ditiol. Los profundos cambios conformacionales que experimentan los compuestos 11 tras la oxidación explican sus propiedades electroquímicas. Medidas de radiólisis de pulso, esto es, la oxidación monoelectrónica de 11,a,c inducida por radicales, conduce a las especies catión radical (11,a,c.+), las cuales dismutan para generar las respectivas especies dicatiónicas (11,a,c2+) y la molécula neutra (11,a,c). [source]

Arborol-Functionalised Tetrathiafulvalene Derivatives: Synthesis and Thin-Film Formation

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2003
Thierry Le Gall
Abstract The syntheses of a series of novel tetrathiafulvalene derivatives substituted with four side-chains terminating in hydrophilic amidoalcohol (arborol) groups are reported, for example the tetrathiafulvalene derivative 15. Some of these arborol derivatives formed thin films by spin-coating from methanol solution onto solid supports such as glass, ITO-coated glass and gold. The quality of the films improved markedly with an increasing number of alcohol substituents at the periphery of the molecule. Optical absorption spectroscopy showed that oxidative doping of these films could be achieved chemically and electrochemically. The observation of low-energy bands in the UV/Vis absorption spectra (,max = 820 nm tailing to ca. 1300 nm) and the moderate levels of conductivity (,rt , 10,4 S cm,1) in these doped films strongly suggest that a significant degree of supramolecular order is present, with ,-, stacking of the TTF cores. To the best of our knowledge this is the first time that semiconducting behaviour has been achieved in molecular arborol systems that possess an electroactive core unit. This work offers the prospect of using spin-coated films of TTF-arborols as semiconducting charge-transport layers in optoelectronic devices. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Synthesis, structure and electrochemical properties of two new unsymmetrical tetrathiafulvalene derivatives

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2005
Ming Xu
Two new unsymmetrical tetrathiafulvalene (TTF) derivatives, 2,3-bis(cyanoethylthio)-6,7-(methyl-ethylenedithio)tetrathiafulvalene (6a) and 2,3-bis(cyanoethylthio)-6,7-(cyclopentodithio)tetrathiafulvalene (6b), have been prepared and characterized by NMR, MS, IR and Elemental analyses. The molecular structures have been determined by X-ray crystallography. Their redox properties have been investigated by cyclic voltammetry in dichloromethane solution and each compound shows two reversible single-electron redox couples. [source]