Conductors, tetrathiafulvalene-based

Tetrathiafulvalene-Based Conductors Containing Organometallic Components... 

Recent synthetic advances of tetrathiafulvalene-based organic conductors 04BCJ43. 

T. Otsubo and K. Takimiya, Recent synthetic advances of tetrathiafulvalene-based organic conductors. Bull. Chem. Soc. Jpn., 77, 43-58 (2004). 

Formigue M, Batail P (2004) Activation of hydrogen- and halogen-bonding interactions in tetrathiafulvalene-based crystalline molecular conductors. Chem Rev 104 5379-5418... 

In recent years, the amount of research time devoted to materials chemistry has risen almost exponentially and sulfur-based radicals, such as the charge-transfer salts based upon TTF (tetrathiafulvalene), have played an important role in these developments. These TTF derivatives will not be discussed here but are dealt with elsewhere in this book. Instead we focus on recent developments in the area of group 15/16 free radicals. Up until the latter end of the last century, these radicals posed fundamental questions regarding the structure and bonding in main group chemistry. Now, in many cases, their thermodynamic and kinetic stability allows them to be used in the construction of molecular magnets and conductors. In this overview we will focus on the synthesis and characterisation of these radicals with a particular emphasis on their physical properties. 

The earliest considerations of how electrical conductivity might be associated with molecular materials emphasized the polarizability of the constituent molecules as the most important factor (65JCP(42)4307). The efforts of synthetic chemists to devise an organic conductor based solely on these ideas were unsuccessful. Discovery of the electrical conductivity in the material prepared from A-2,2 -bi-l,3-dithiolylidene (tetrathiafulvalene, TTF ... 

One approach to chiral conductors using the counterions as the source of asymmetry is that employed in the preparation of a conductor based on bis(ethylenedithio)-tetrathiafulvalene (BEDT, Fig. 3) [39]. When this organic donor is electrocrystallised in the presence of the L-tartrate salt K2[Sb2 (L-tart)2] the compound that is formed is BEDT3Sb2(L-tart)2 MeCN. Thus, the BEDT is in a mixed valence state, with two third charge per molecule on average. The salt, which pertains to the P2i2i2i space group, has layers of donor molecules and ions derived from BEDT which alternate with layers of the chiral counter-ions. 

As part of an effort to synthesize novel organic conductors based upon tetrathiafulvalene, 4,6-dihydrothieno[3,4-rf]-1,2,3-thiadiazole (70) was prepared from the hydrazone (100), together with an appreciable amount of 4,5-dihydrothieno[2,3-c/]-l,2,3-thiadiazole (99) (89TL7249). 

D. O Hare),many new findings have appeared in this field. First of all, new superconducting phases based on [M(dmit)2] complexes have been isolated, and the first neutral metallic conductors based on nickel complexes of the TTF (tetrathiafulvalene)-extended dithiolene... 

Organic r-donors based on tetrathiafulvalene (TTF) and its derivatives have been the subject of numerous studies in organic media, due to their ability to form charge-transfer compounds and their wide range of potential applicability as, for instance, molecular conductors, semiconducting films, electroactive polymers (including low-band gap materials), molecular switches, and superconductors [8]. 

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