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Organic Rechargeable Batteries
Published in Toshio Naito, Functional Materials, 2019
Tetrathiafulvalene (TTF) is a well-known π-electron donor. Its oxidized species are stabilized by the aromatic character of the 1,3-dithiolylium ion, with six π-electrons, as shown in Fig. 4.16 [34, 35]. It exhibits two successive one-electron reversible redox processes. The redox potentials of TTF are 3.10 and 3.50 V versus Li/Li+, in propylene carbonate containing 1 M LiBF4 as an electrolyte. The radical cation is stabilized by the delocalization of a positive charge between two 1,3-dithiole rings, in addition to aromatic stabilization. Aromatic stabilization in (TTF)2+ is larger than that in (TTF)˙+ because (TTF)2+ has two 1,3-dithiolylium rings. However, on-site coulomb repulsion between two positive charges significantly destabilizes the dicationic state. In other words, the second oxidation potential (E2ox) is much more positive than the first oxidation potential (E1ox). As a result, the two-electron oxidized state of TTF is less stable than the one-electron oxidized state. The TTF and its derivatives have been utilized as components for metallic and superconducting molecular conductors, and the TTF derivatives have actually produced a great number of molecular metals and superconductors [36–39].
Fundamentals of Molecular Layer Deposition (MLD)
Published in Yoshimura Tetsuzo, Thin-Film Organic Photonics, 2017
It is known that tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) combine through charge transfers between them to form molecular crystals of charge transfer complexes. From this property, it is expected that MLD utilizing electrostatic force might be accomplished using these molecules. Figure 3.19 shows MLD of TTF on TCNQ. As in the PMDA/DNB, PMDA/DDE, and TPA/PPDA systems, monomolecular adsorption occurs. TTF re-evaporates when shutter A is closed, however, suggesting that the connecting force between TTF and TCNQ is not sufficient. Since the time constant for thickness decay increases with decreasing substrate temperature, by optimizing the substrate temperature, we might be able to apply MLD to charge transfer complexes.
Control of Self-Assembling Behavior ofOrganic Polymers via Charge Transfer(CT) Interaction of π-Conjugated Planes
Published in Atsushi Nagai, Koji Takagi, Conjugated Objects, 2017
Tetrathiafulvalene (TTF) is π-conjugated organosulfur cycliccompound possessing 14 π-electrons, and it can act as an electrondonor to present CT interaction.36 Martin and coworkers reportedsynthesis of supramolecular polymers by using a heteroditopicmonomer consisting of a fullerene (C60) and exTTF (2-[9-(1,3-dithiol-2-ylidene]anthracen-10(9H)-ylidene)-1,3-dithiole),37 which
Synthesis and liquid crystal behaviour of tetrathiafulvalenes/1,3-dithiol-2-thione and p-cyanoazobenzene
Published in Liquid Crystals, 2021
Lina Ma, Yan Xia, Dongfeng Li, Ruibin Hou
Among the many π-functional units employed in molecular materials, tetrathiafulvalene (TTF) and its derivatives are interesting heterocyclic systems, particularly because they can be oxidised to produce conductive materials through π-stacked columnar arrangement in bulk and thin film states [21–24]. TTF derivatives with LC properties are promising semiconductor materials because their ordered molecular structures in the LC phase generate fewer structural defects on a macroscopic scale. Although a considerable number of TTF derivatives have been synthesised to date, only a few reports describe TTF derivatives with LC properties. Consequently, establishing structure–property relationships for this family of compounds has not yet been possible [25–29].
Engineering the electronic properties of siligraphene sheets by organic molecules: a density functional theory investigation
Published in Molecular Physics, 2021
In this paper, we explore the effect on the electronic properties of siligraphene sheets of the adsorption of organic molecules by density functional theory (DFT). The organic molecules investigated in this work are tetracyanoethylene (TCNE), tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ). Those molecules are selected since they are investigated intensively in organic chemistry due to their wide range of applications for the fabrication of electronic devices.