Poly tetrathiafulvalene

Examples poly(tetrathiafulvalene) dimeric species are also formed [127,137].)... 

Gruber H, Patzsch J, Schrodner M, Roth HK, Eanghaenel E (1991) Electrical properties of poly(tetrathiafulvalenes). Synth Met 42 2331-2334... 

Poly(monosulfide)s, 23 702-711 aliphatic, 23 702-704 aromatic, 23 706 conjugated polymers, 23 709 macrocyclic polythioethers, 23 707 poly(arylene sulfide)s, 23 704-706 poly(monosulfide ketone)s, 23 709-711 polythiophenes, 23 708 tetrathiafulvalene polymers,... 

Previous work on the synthesis of TTF (tetrathiafulvalene) containing polymers has been reported by at least seven groups of researchers. Most of this work concerns condensation 6,7,8,9 polymers or polymers made from vinyl substituted TTF molecules . Without exception, the polymers produced by these methods have been largely unacceptable for subsequent physical study because of their brittle,intractable, highly insoluble nature. Only by reaction of a suitably monofunctionalized TTF derivative with the preformed polymer poly(vinylbenzylchloride) has it been found possible — to prepare soluble TTF homopolymers with more manageable physical properties. 

The electronic properties of n-conjugated polymers reflect well the basic electron-withdrawing or electron-donating properties of the components of the Ti-conjugated polymer [62]. In view of the electrochemical reduction potential, the thiophene unit and tetrathiafulvalene unit (Nos. 8 and 9 in Table 1) have a similar electronic effect in PAEs. It is reported that poly(arylenevinylene)s are also susceptible to electrochemical reduction [63, 64]. Due to the electron-accepting properties, PAEs are usually inert in electrochemical and chemical (e.g.,by I2 [54]) oxidation. 

Polymeric tetrathiafulvalene derivatives show a more complicated behaviour (Table 9). Up to 0.4 mole (I) per monomer unit, poly-1 -(p-phenylene)-2,3-dimethyltetrathiafulvalene 19, R = Me, gives spectra consistent with the presence of I3 , but at one atom of iodine per monomer and above, the spectra change. Three subspectra are seen, with parameters close to those ofI5", but the intensity ratios are not the expected 2 2 1. The data of Table 9 show that two of the subspectra for I5 are unresolvable from the two sets found for I3 ... 

A successful donor has been bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET). The structure of ET is depicted in Fig. 4-41. The infrared and Raman frequencies of BEDT-TTF and BEDF-TTF-t/g have been reported and assignments made (63). Figure 4-42 shows the Raman spectra of several salts in the region of 800-50 cm-1. Here, the research was done to determine the nature of the poly iodides in the molecule (64). 

Redox polymer — Redox polymers contain electrostatically and spatially localized redox sites, which can be oxidized or reduced. The redox polymers can be divided into subclasses 1) polymers that contain covalently attached redox sites, either built in the chain or as a pendant group. The redox centers may be organic molecules (e.g., tetrathiafulvalene, tetra-cyanoquinodimethane), organometallic molecules (e.g., - ferrocene), or co or dinative ly attached redox couples (e.g., polymerized metal bipyridine(bpy) complexes) 2) ion-exchange polymeric systems, where the redox-active ions are held by electrostatic binding (e.g., Fe(CN)g- 4- in protonated poly(vinylpiridine) or Ru(bpy)j+/2+ in -> Nafion [i]. 

Despite their inherent electronic advantages, CT complexes and radical cation salts tend to be brittle and unprocessable. This problem might be overcome by the incorporation of oligomeric tetrathiafulvalenes in polymers, whereby the TTFs can be part of a main-chain or side-chain polymer. The key concern thereby is to achieve the suitable packing of the donor moieties, which is, of course, less perfect than in the crystalline state. Remarkably, the rigid-rod poly-TTF 164 could be made recently by a precursor route in which 164 is made by dimethyl disulfide extrusion of the precursor polymer (scheme 39). The electrical conductivity after iodine doping amounts to 0.6 S/cm [221]. Other examples of TTF-containing polymers, either in the backbone [222] or in the side-chain [223], are summarized in chart 25. 

Solvent effects may in certain cases contribute to the charge conduction mechanism with polymer films, however, as the work of Kaufman et al (24) has shown. On the basis of spectral data, these workers have concluded that mixed valence states of tetrathiafulvalene (TTp2+, TTF" ", etc.) are not essential to charge-conduction in poly TTF films, but that electron hopping modulated by the solvent-induced pendent group collisions is. An additional phenomenon related to the electrolyte noted by this group is that ion flow into the polymer phase appeared to limit the kinetics of oxidation reactions in these films. 

Another similar bistable side-chain poly[2]catenane 64 was rejxjrted by Stoddart and coworkers (Scheme 17.19), using a method similar to that employed when preparing 59 [122]. The [2]catenane monomer 60 bearing an alkyne group was first prepared, as described above. As shown in Scheme 17.19, monomer 60 was bistable and composed of two switchable isomers a ground-state co-conformation (GSCC) and the metastable-state co-conformation (MSCC), which corresponded to the locations of the tetrathiafulvalene (TTF) and dioxynaphthalene (DNP) units of... 

Huchet, L., S. Akoudad, E. Levillain, J. Roncali, A. Emge, and P. Bauerle. 1998. Spectroelectro-chemistry of electrogenerated tetrathiafulvalene-derivatized poly(thiophenes) Toward a rational design of organic conductors with mixed conduction. J Phys Chem B 102 7776-7781. 

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