35079-56-2

Upstream product

• 31366-25-3 tetrathiafulvalene 
• 84-58-2 2,3-dicyano-5,6-dichloro-p-benzoquinone 
• 4587-25-1 2,3-dibromo-5,6-dicyano-1,4-benzoquinone 
• 118-75-2 chloranil 
• 1518-16-7 7,7',8,8'-tetracyanoquinodimethane 
• 527-17-3 Duroquinone 

Downstream Products

• 31366-25-3 tetrathiafulvalene 
• 84-58-2 2,3-dicyano-5,6-dichloro-p-benzoquinone 
• 741268-81-5 [5,6]fullerene-C₇₀ 
• 4587-25-1 2,3-dibromo-5,6-dicyano-1,4-benzoquinone 
• 118-75-2 chloranil 
• 1518-16-7 7,7',8,8'-tetracyanoquinodimethane 

Relevant academic research and scientific papers

A systematic study of the variation of tetrathiafulvalene (TTF), TTF+ and TTF2+ reaction pathways with water in the presence and absence of light

The chemistry of the strongly electron donating tetrathiafulvalene (TTF) molecule is exceptionally well known, but detailed knowledge of the chemistry of its technologically important one (TTF+) and two (TTF2+) electron oxidised redox partners is limited. In this paper, the different pathways that apply to the reaction of TTF, TTF+ and TTF2+ with water have been identified in the absence and presence of light. On the basis of data obtained by transient and steady state voltammetric methods in CH3CN (0.1 M Bu4NPF6) containing 10% (v/v) H2O, TTF is shown to participate in an acid base equilibrium reaction with HTTF+, with H2O acting as the proton donor. In contrast, TTF+ generated by one electron bulk oxidative electrolysis of TTF remains unprotonated and fully stable in the presence of 10% H2O in the dark. However, when this cation radical is exposed to white or blue (λ = 425 nm) light, TTF+ is photoreduced to TTF, with oxidation of water to give oxygen (detected by a Clark electrode) and protons that react with TTF to give HTTF+ as the counter reaction. Again emphasising important reaction pathway differences associated with each redox level, TTF2+ generated by bulk two electron oxidative electrolysis of TTF reacts rapidly with water, even in the dark, to give TTF+, protons, HTTF+ and oxygen as the products.

Charging a Li-O2 battery using a redox mediator

The non-aqueous Li-air (O2) battery is receiving intense interest because its theoretical specific energy exceeds that of Li-ion batteries. Recharging the Li-O2 battery depends on oxidizing solid lithium peroxide (Li2O2), which is formed on discharge within the porous cathode. However, transporting charge between Li 2O2 particles and the solid electrode surface is at best very difficult and leads to voltage polarization on charging, even at modest rates. This is a significant problem facing the non-aqueous Li-O2 battery. Here we show that incorporation of a redox mediator, tetrathiafulvalene (TTF), enables recharging at rates that are impossible for the cell in the absence of the mediator. On charging, TTF is oxidized to TTF+ at the cathode surface; TTF+ in turn oxidizes the solid Li2O 2, which results in the regeneration of TTF. The mediator acts as an electron-hole transfer agent that permits efficient oxidation of solid Li 2O2. The cell with the mediator demonstrated 100 charge/discharge cycles.

In Situ Electrochemical EPR Studies of Charge Transfer across the Liquid/Liquid Interface

The in situ measurement of EPR spectra of radical ions generated at the polarized liquid/liquid interface is described in relation to the 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrachloro-p-benzoquinone (TCBQ), and 2,3,5,6-tetrafluoro-p-benzoquinone (TFBQ) radical anions and the tetrathiafulvalene (TTF) radical cation. TCNQ and TTF were chosen as model compounds with which to quantify the performance of a novel liquid/ liquid electrochemical EPR cell. The anion radical of TCNQ and the cation radical of TTF in 1,2-dichloroethane (DCE) were produced at the water interface by electron transfer from/to the aqueous-phase ferricyanide/ferrocyanide redox couple by applying a potential difference between the two phases with a four-electrode potentiostat. The EPR signal intensity (at constant magnetic field) of the resultant organic radicals was monitored during potential step experiments which indicated that the EPR data could be modeled in terms of diffusional transport. TCBQ and TFBQ were chosen as compounds to model the electron transfer behavior of biologically important quinones at the oil/water interface. The EPR and voltammetric data obtained from TCBQ/TCBQ-· and TFBQ/ TFBQ-· indicated unambiguously that the two semiquinones are stable at the DCE/water interface and do not undergo immediate protonation.

Homogeneous and Heterogeneous Electron Transfer Rates of the Tetrathiafulvalene-System

Using ESR spectroscopy and cyclic voltammetry the rate constants of homogeneous and heterogeneous electron self exchange in the system TTF/TTF+radical were measured at different temperatures in solvents of different polarities and relaxation times (TTF = tetrathiofulvalene = 2-(1,3-dithiol-2-ylidene)-1,3-dithiol).The rate constants were expressed by the preequilibrium encounter model for adiabatic processes.For both reactions the results are discussed in terms of Marcus's theory for the reorganization of ellipsoidal molecules in the overdamped relaxation case.From the experiments the geometric term g = 1/r - 1/d'was derived and compared with model calculations ( r = mean molecular radius, d'= formal distance between the reactants resp. reactant and image charge).Approximately interaction energies of the reactants (in the homogeneous case) and double layer correction (in the heterogeneous case) can be neglected.Preexponential and activation terms of the rate constants agree satisfactorily with the theory. g(het) is about the tenfold of g(hom).This is explained by an increased d' caused by strong adsorption of the counterions of the supporting electrolyte on the electrode.

An ESR Study of the Radical Cations of Tetrathiafulvalene (TTF) and Electron Donors Containing the TTF Moiety

Hyperfine data and g factors are reported for the radical cations of tetrathiafulvalene (TTF; 1) and of its derivatives 2-13.From the intense satellite spectra of 1+. - 13+. not only the coupling constants of the 33S isotopes in the TTF moiety could be determined, but also, in favourable cases, those of the 13C isotopes in the central double bond.The former values range from 0.370 (8+.) to 0.470 mT (4+.) and the latter from 0.255 (8+.) to 0.360 mT (4+.) in the radical cations of bis(ethylenedithio)-TTF (8+.) and tetracyano-TTF (4+.).The radical cation of TTF (1+.) exhibits intermediate values, 0.425 for the 33S and 0.285 mT for the 13C isotopes.The spin population in 1+. - 13 +. resides, to a large extent, in the central S2C = CS2 part of the ?-system.It tends to increase (decrease) by substitution with electron-accepting (donating) groups in the 2,3,6,7-positions of TTF.

Tetrathiafulvalenes. XXII. - Redox- and Spectroscopic Properties of Tetratiafulvalenes (TTF) and Tetraselenafulvalenes (TSF) and their Mono- and Dications

The polarographic oxidation potential of TTF is decreased by alkyl- and increased by aryl-substituents.The oxidation potentials of arylated TTF can be correlated with ?(+)-constants (ρ = 0,1).TSF are weaker donors than the respective TTF.Alkyl substitution at TTF causes a bathochromic shift and aryl substitution a hypsochromic shift of the longest wavelength absorption band.In the mono- and dications of TTF a bathochromic shift of this absorption band is observed by alkyl- as well as aryl-substituents which is especially pronounced, when the molecule is planar.

Dimer Cation Formation in Anionic Microemulsion Media. Duroquinone-Sensitized Photooxidation of 2,6-Dimethylnaphthalene and Tetrathiafulvalene

Flash photolysis studies using a ruby laser (λ=347 nm, doubled line) were performed on the systems duroquinone (DQ)/2,6-dimethylnaphthalane (DMN) and DQ/tetrathiafulvalene (TTF) principally in sodium hexadecyl sulfate (SCS) microemulsion media.Electron transfer from both DMN and TTF to triplet duroquinone with efficient charge separation to produce the product cations and anion was observed in these media.Identical experiments performed in homogeneous media demonstrated electron transfer but with less efficient charge separation and consequently lower product ion yields.Dimer cation formation of both DMN and TTF, i.e., (DMN)2+ and (TTF)2+, in the anionic microemulsion media was readily detected.The formation of (TTF)2+ was reverified by pulse radiolysis experiments.Although tetrathiafulvalene stacks easily in organic conducting salts and thus should have no difficulty in obtaining the supposed sandwichlike configuration of the dimer, no previous reports announce its detection.Dimer cation formation of aromatic compounds in microemulsion media is unique in itself since the majority of previous studies of this type involved γ irradiation of substrate solubilized in glassy alkane matrices at low temperatures (77 K).The dimer formation constant for DMN was evaluated graphically as K=4.76*102.

Electron Transfer Reaction between Δ2,2'-Bi-1,3-dithiole (TTF) and 7,7,8,8-Tetracyanoquinodimethane (TCNQ). Electron Donating Property of TTF

The reaction between Δ2.2'-bi-1,3-dithiole (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) in acetonitrile solution, TTF + TCNQ = TTF +. =TCNQ -., was analyzed spectrophotometrically.The thermodynamical data of chemical equilibrium were determined to be K=(2.8 +/- 0.1)*10-3 at 11 deg C, ΔH=-6.7 +/-1.3 kJ mol -1 and Σ=-72.8 +/- 17 JK-1mol-1.The reaction-rate study of the equilibrium in several solvents was also made by temperature-jump technique.The difference in the electron-donating properties between TTF and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) is discussed by comparing the results with those of the reaction between TMPD and TCNQ.

One-electron Reduction Potentials of Several Electron Acceptor Molecules and Cation Radicals of Donors

Reversible one-electron reduction potential values of several electron acceptor molecules and cation radicals of donors were estimated by means of the equilibrium constant of electron transfer reaction between ion radicals in acetonitrile solution, and the results were compared with the observed electrochemical data.