Tetrathiafulvalene crystal structure

The (EDT-TTF-I)2Br salt described above [36] and the 1 1 (TTFI4)I salt reported by Gompper [51] were the only structurally characterized salts with simple halide anions until Imakubo recently described an extensive series of Cl" and Br" salts from several ortho-diiodo tetrathiafulvalene, tetraselena-fulvalene and dithiadiselenafulvalene derivatives (Scheme 8) [62], The X-ray crystal structure analysis of the nine salts described there show a variety of halogen bonded motifs, demonstrating the adaptability of the supramolecu-lar interactions to other structural requirements imposed by the nature of the heteroatoms (O, S, Se) in the TTF frame. Indeed, in (EDT-TTF-l2)2X-(H20)2 (X = Cl, Br), a bimolecular motif (Fig. 6) associates two partially oxidized EDT-TTF-I2 molecules with one Br" anion and one water molecule. 

The redox reaction shown in Scheme 7.60 results in the formation of an amide a-radical and tetrathiafulvalene cation-radical. These initially formed a-radical and cation-radical combine to give salts of the S-arylated tetrathiafulvalene (a minor product) and C-alkylated tetrathiafulvalene (the main product). The latter demonstrates an unprecedented carbon-carbon bond formation with the cation-radical of tetrathiafulvalene the structure depicted was confirmed by single crystal x-ray analysis (Begley et al. 1994). 

The crystal structure of pentathiepino [6,7- indole has been determined <1994TL5279>. X-Ray crystal structure analysis revealed that 4,5-ethylenedithio-4,5-pentathiotetrathiofulvalene <1999AM758> moiety has a bent structure resembling the molecular structure of neutral bis(ethylenedithio)tetrathiafulvalene and that the pentathio group adopts a chair-formed conformation. The intradimer interplane distance is 3.35 A, which is much shorter than the interdimer one (4.45 A). In a molecule, there are many intermolecular S-S contacts shorter than the sum of the van der Waals radii (3.7 A), and a two-dimensional network of sulfur atoms was developed between the pentathio groups and tetrathiafulvalene moieties. Furthermore, chlorobenzene molecules are beside the anion and occupy the void space as the interstitial solvent. They are also located on the mirror plane and are disordered at two positions with inversion symmetry because of the cavity structure of the void space. 

Only a few X-ray crystal structure determinations on 1,3-dithioles have been carried out. Some typical bond lengths and bond angles of the tetrathiafulvalene (5), l,3-dithiole-2-thione derivative (6) and 1,3-dithiolanes (7) and (8) are given in Tables 2 and 3, respectively. Also bond lengths and bond angles of the radical cation of tetrathiafulvalene in the tetrathiafulvalene-7,7,8,8-tetracyanoquinodimethane complex have been determined <74AX(B)763>. 

Recently, Heiberg et al. [26] have studied polarizabilities of the intermolecular contacts in bis(ethylenedithiolo)tetrathiafulvalene (BEDT-TTF) and bis(ethylenedioxy)tetrathiafulvalene (BEDO-TTF) molecular crystals by polarizing microscope techniques. The principal refractive indices and the corresponding optical axes have been calculated by tensorial addition of the bond polarizabilities of all bonds in the molecules. Comparison of calculated and measured values of the relative polarizabilities showed that the polarizabilities of the molecules only cannot yield the measured indicatrix and axes angle. Thus polarizabilities with other orientations must be involved. From the crystal structure of the molecular crystals it is known that 10 and four different contacts exist between the molecules of BEDT-TTF and BEDO-TTF, respectively, with contact distances lower than van der Waals distances. Assigning of polarizabilities of these contacts can explain the measured behavior. 

Figure 1 Prototype molecules TTF (tetrathiafulvalene and TMTSF (tetramethyl-tetraselenafulvalene) which are used for the elaboration of organic conductors TTF-TCNQ or superconductors (TMTSF)2X. View of the crystal structure of some molecular superconductors (a) (TMTSF)2PF6 (b) (alkali)3 C (c) (BEDT-TTF)2Cu(SCN)2 side view (d) view along the axis perpendicular to the conducting plane.

The synthesis, crystal structure and electrochemical properties of a silver(l) coordination derivative of 2,3-dimethylthio-6-pyridyl tetrathiafulvalene <2007JCC2319> and ruthenium(n) polypyridine complexes [Ru(bpy)3- (TTF-dppz)4(PF6)2, (bpy = 2,2 -bipyridine dppz = 4, 5 -bis(propylthio)tetrathiafulvenyl[i]dipyr-ido[3,2-r 2, 3 -f]phenazine) <2007MI1504> were also investigated. 

Mas-Torrent, M. et ah. Correlation between crystal structure and mobihty in organic field-effect transistors based on single crystals of tetrathiafulvalene derivatives, J. Am. Chem. Soc., 126, 8546, 2004. 

Recently, the crystal structures of two compounds with linked polyanions have been described [bettf]8[PWi Mn039] 2H2O, (bettf = bis(ethylenedithio)-tetrathiafulvalene), and [NEt3H]5[XW 1C0O39] 3H2O, X = P, As. " Both have chains of anions, connected through oxygen atoms. 

Becher, J. A pyiTolo-tetrathiafulvalene cage Synthesis and X-ray crystal structure. Org. Lett. 2802. 4. 4189-4192. Bartoli, S. Roelens. S. Binding acetylcholine and tetra-methylammonium to a cyclophane receptor Anion s contribution to the cation-jt interaction. J. Am. Chem. Soc. 2002. 124. 8307-8315. 

The materials examined here are salts of the sulphur-based donor, (BEDT-TTF)2X, where BEDT-TTF or ET is bis(ethylenedithio)tetrathiafulvalene, and X are linear inorganic anions of length 7.8 - ca. 10.3 A [3]. This donor has been shown to crystallize in different crystal structures with the same anion and under the same conditions. For example, there are five different crystal phases for X = Ag(CN)2 [4]. The EPR linewidths vary from 1 to 150 Oersted at room temperature, depending on the crystal structure. On the other hand, the... 

The synthesis, electrochemical and electronic absorption properties, crystal structure, and molecular orbital calculations of catechol-appended TTF derivative 67 (13TL4015) and a review into chalcogen-rich compounds as electron donors (B-13MI99) have been published. The synthesis, structure, and electronic properties ofthe bromophenyl-substituted dithiafulvenes 68-70, tetrathiafulvalene vinylogues (TTFVs) 71-73, and the unusual spiro-compound 74 produced from 70 have been reported... 

In the above radical-cation salts, the crystal contains partially oxidized donors, while the electroneutrality is achieved by the presence of closed shell anions. The structural requirements necessary for electrical conductivity in solid salts can also be met upon mixing of donors and acceptors in the resulting charge-transfer (CT) complexes both the donor and acceptor exist in a partially oxidized and reduced state, respectively. Famous examples are the conducting CT complexes formed upon mixing of perylene (112) [323. 324] and iodine or of tetrathiafulvalene (TTF, 119) as donor and 7,7,8,8-tetracyanoquinodimethane (TCNQ, 120) as acceptor [325-327] the crucial structural finding for the... 

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