TTF halides

The loss of halogen in the irradiated areas, as expected, leads to a dramatic drop in conductivity. The TTF halide films have conductivities on the order of 10-20/ohm-cm. Irradiation causes the conductivity to drop by over 9 orders of magnitude. High conductivity of the initial resist films is a useful property since it prevents static charge build upon E-beam irradiation which can lead to concomitant loss of image resolution. 

There are several interesting families of inorganic mixed-valence compounds that we have not discussed here (see Yvon, 1979 McCarley, 1982). For example, there are metal-cluster compounds such as the Chevrel phases, M,jMo6X8(X = S or Se) and condensed metal-cluster chain compounds such as TlMojScj, TijTe, NaMo O and M PtjO. TTF halides and TTF-TCNQ complexes (Section 1.9) constitute molecular mixed-valent systems in which the mixed valency is associated with an entire molecule the charge on TTF in such compounds is nonintegral. The structure of TTF-Br(, 79 and... 

What makes the TTF-TCNQ family distinct from the other salts of TCNQ with cations, such as alkali metals and tetramethylammonium, is that the charge transfer,/ in the TTF-TCNQ family is incomplete (f < 1). TTF-TCNQ members are also different from the TTF-halides in the TTF-halides, where the charge on each halide atom is unity, partial charge transfer (mixed valency) is realized by the formation of nonstoichiometric materials, while in the TTF-TCNQ family, the composition is stoichiometric (1 1), but mixed valence arises because of partial electron-transfer. 

Scheme 4 Typical halogen bonded motifs involving a partially oxidized TTF molecule such as EDT-TTF-I with halide (top) or cyanometallate (bottom) counter ions...

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. 

Only a few recent examples of halogen bonding of halogenated TTFs with halometallate anions have been described and this most probably represents a broad development field in this area. Indeed, these halometallate salts offer a wide variety of complexes and specifically here a large variation of the ratio of anion charge vs number of halide atoms, as already discussed above in the comparison between Br and 13 salts. This point is illustrated by the superb structures of two salts of EDT-TTF-I2 with the polymeric one-dimensional PbV (Fig. 9) and two-dimensional (Pbs/eDi/eh) anions where shorter C -1- -Ianion contacts are observed with the linear Pbl3 chains... 

Following Dehnicke s report in 1996 on the co-crystallization of diiodoacety-lene (DIA) with various halide anions to form two-dimensional networks through C-I X interactions [93], Kato et al. investigated these supramo-lecular anions in the electrocrystallization of classical TTFs such as BEDT-TTF. 

Brunn, K., Endres, H. and Weiss, J. (1988). Reactions of the organic donor tetra(methylthio)tetrathiafulvalene with halides of copper and gold (TTM-TTF)(CuI)2, (TTM-TTF)+[CuCl2r, (TTM-TTF)2+[AuClJ2-and C4H6S4AuC12. Z. Naturforsch, Teil B. 43, 113. 

More recently, elegant mechanistic studies on intramolecular Meer-wein reactions by Beckwith et al. considerably extended the utility of diazonium salts. They showed that many electron donors could convert an arenediazonium cation into an aryl radical which cyclized in good yield to form dihydrobenzofurans and indolines. The final radical was functionalized as a halide, sulfide, or ferrocene. Thus, the credentials of diazonium salts as electron acceptors were well established, and the stage was set to investigate the interaction between diazonium salts and TTF. 

Synthesis ttf aliphatic carhoxySe acids, esters, and anodes. Sodium tetracarbonyl-ferrate(-ll) (1) reacts with aliphatic halides and tosylates to give anionic alkyltetra-carbonyliron(O) complexes (2). In the presence of carbon monoxide these undergo... 

Regarding the synthesis of tetrathiafulvalenes (TTFs), the preparation of a series of substituted naphtho-1,3-dithiole-2-thiones 150 in good yields (50-78%), from 3,4,7,8-tetrachloronaphtho[l,8-f, 5,4-fV ]bis(l,2-dithiole) 149, and an excess of sodium trithiocarbonate and alkyl halide were reported (Scheme 17) <1998EJ01577>. The monosubstitution products 151 were formed when equimolar quantities of derivatives 149 and sodium trithiocarbonate were used. Upon desulfurization with mercury(ll) acetate, the bis- and monosubstituted l,3-dithiol-3-thiones 150 and 151, respectively, yielded the corresponding l,3-dithiol-2-ones, whereby dechalogenation of 150 (R = 7-CsHii) with triethyl phosphite gave rise to the TTF 152. 

The stannylated TTF derivative 707, prepared from the corresponding TTF-Li, reacted with aromatic halides to afford derivatives 708 in moderate yields (Equation 92) <1996J(P1)2391, 2001EJ073, 2003TL9275>. 

Polymers of TTF also react with bromine and iodine providing radical-cation halides. ... 

Anodic oxidation of TTF in the presence of halide ions leads to the formation of mixed-valence salts, TTFXo.y, and the electrochemical behavior of these salts was studied by means of carbon paste electrodes [179]. 

On the other hand, the introduction of only one C-linked substituent is difficult, the first report of such a monofunctionalization of TSF, without the formation of multisubstituted derivatives, is very recent (93S465) and shows that quite different conditions are needed to carry out this reaction than those used to monofunctionalize TTF. The synthetic strategy involves the generation of the tetraanion, followed by trapping with less than one equivalent of the corresponding electrophile (acyl halides were used). The main drawback with this method is that the desired products... 

Bond Angles and CuX Frameworks in TTC -TTF (Ls,) Complexes of Copper(I) Halide... 

The physical properties of the thallium halides have been tabulated. Crystalline TIF has a distorted rock-salt lattice, with two independent thallium sites. The thermod5mamic properties of the solid have been reassessed. At high temperature, the vapor phase contains TtF and TI2F2 molecules and matrix isolation studies have demonstrate the presence of both TIF and TI2F2 in the solid the dimers have linear symmetry. 

Since triiodide is the longest one among the symmetric linear polyhalides, we have searched for longer anions, among a variety of metal halides and metal pseudohalides, where metals are Cu, Ag, Hg, Ni, Pd, etc. and the pseudohalides are CN, OCN, SCN, SeCN, etc. In the following we describe only two BEDT-TTF complexes obtained in this process, namely superconducting Cu(NCS)2 and metallic KHg(SCN)4 salts however, neither was found to be p-phase furthermore, the anions were neither symmetric nor linear, but formed polymeric clusters. 

Imakubo T, Shirahata T, Herve K, Ouahab L (2006) Supramolecular organic conductors based on diiodo-TTFs and spherical halide ion X—(X=C1, Br). J Mater Chem 16 162-173... 

CD2CI2, acetone-Je and CD3CN [121], which revealed that the incorporation of one or more electron-rich TTF subunits improved the binding ability and changed the binding selectivity. The complexation for halides was also monitored by cyclic voltammetry in 1,2-dichloroethane, which revealed electrochemical response to CF and Br ions. 

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