Tetrathiofulvalene tetracyanoquinodimethane

Espinosa, E., Molins, E. and Lecomte, C. (1997), Electron density study of the one dimensional organic metal bis(thiodimethylene)-tetrathiofulvalene tetracyanoquinodimethane, Phys. Rev. B, 56(4), 1820-1833. 

NEUTRON AND X-RAY DIFFUSE SCATTERING STUDY OF TETRATHIOFULVALENE TETRACYANOQUINODIMETHANE (TTF - TCNQ)... 

Interest in electrically conducting polymers began in the mid-1960s with the su estion of Little [17] in his theoretical studies that some organic materials could become superconductors. The first example that has been extensively studied is tetrathiofulvalene-tetracyanoquinodimethane (TTF-TCNQ) and its derivatives. The first covalent polymer exhibiting the electronic properties of a metal was polymeric sulfur nitride, (SN), which attracted much attention in the mid- to late 1970s. 

Batra, I.P., Bennett, B.I., Herman, F. Simple molecular model for crystalline tetrathiofulvalene-tetracyanoquinodimethane (TTF-TCNQ). Phys. Rev. B 11, 4927-4934 (1975)... 

There is a very short list of organic semiconductors with reported thin-film field-effect mobilities greater than 1 cm2 V-1 s h These include pentacene, sexithio-phene [5a], and anthradithiophene [17]. If we extend this list to include single crystal and n-type materials, we can add perylene [18], rubrene [19], copper phtha-locyanine (CuPc) [20], tetracyanoquinodimethane (TCNQ) [21], and dithiophene-tetrathiofulvalene (DT-TTF) [22] - still a short list. 

Infinite Stacks of TCNQ and TTF Molecules.—The quasi one-dimensional charge-transfer molecular crystal TCNQ (7,7, 8,8 -tetracyanoquinodimethane)-TTF (tetrathiofulvalene) has received considerable attention in the past decade because of its interesting solid-state physical properties. In recent publications81... 

Figure 3 Examples of molecular conductor building blocks. TTF, tetrathiofulvalene TSF, tetraselena-fulvalene TMTSF, tetramethyltetraselenafulvalene TCNQ, tetracyanoquinodimethane BEDT-TTF, bis-ethylene-dithio-tetrathiofulvalene EDT-TTF, ethylene-dithio-tetrathiofulvalene dmit, dimercaptoisotri-thione or 2-thioxo-l,3-dithiole-4,5-dithiolato dmise, 2-selenoxo-l,3-dithiole-4,5-dithiolato dddt, 5,6-dihydro-...

Alternatively to carbon pastes, conducting organic salts have been used to imbed bioactive components, in particular to immobilize enzymes. The redox mediator tetrathiofulvalene acts as electron donor and forms a solid, conducting salt with the electron acceptor tetracyanoquinodimethane. This salt has a low melting point and can be mixed with proteins to give a conducting... 

It is well known that the mixed three-dimensional molecular crystal built up from alternating 7,7, 8,8 -tetracyanoquinodimethane (TCNQ) and tetrathiofulvalene (TTF) stacks exhibits metallic conductivity owing to charge transfer of about 0.6 from a TTF molecule to a TCNQ unit. For the band-structure calculations of the two stacks we have applied the CNDO/2 method, and in the case of the TCNQ stack also the MINDO/2 method. (No MINDO/2 calculations could be conducted for the TTF chains owing to the lack of a parametrization scheme for sulfur at that time.) All band-structure calculations were performed in the first-neighbor-interaction approximation. This approximation is well justified in view of the large distances between neighboring molecules in the chain. 

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