PPV-AsF

The resistivity ratio (pr) for high quality samples of I-(CH) K-(CH) FeCl3-(CH), PPy-PFe, PANI-CSA, PPV-AsFs, and PPV-HSO4 is less than 2. For some samples [e.g., PANI-CSA, FeCl3-(CH).J, the positive TCR of real metals has been observed at temperatures above 160 K and in the case of PPy-PFe and PPV-AsFs, a positive TCR appears below 10 K. 

The linear temperature dependence of thermopower is typical of that of metals. The T dependence of inelastic scattering time (xin) for PPy-Pp6 and PANI-CSA is in agreement with the prediction for systems very near the M-I transition. An inelastic scat-... 

In their x-ray study, Masse el al. [268] report chemical doping with the oxidizing agents PF5, AsFs in the gas phase and with 98% H2SO4, as well as electrochemical doping (anodic oxidation) in 1 M LiCIO in propylene carbonate. PPV is prepared through the sulphonium... 

Figure 3.29. Cls core-level spectra of (a) undoped (b) 5% AsFs-doped and (c) 7% AsF5-doped PPV Components Ca and Cb arc associated with pristine PPV while component Ct is associated with the oxidized stale. (Reprinted with permission from ref. 139, Am Chem. Soc.)...

Figure 6.62. The ESR linewidth as a function of the spin-orbit coupling Constant, ( (cm ) (After Gordy, 1980 [9]) of the heaviest atom in the polymer backbone PPV-HSO4 [307] PPy-Bp4 [286,328] PPy-CI04 [238,287] PPy-PFe", PPy-TsO , PPy-AsFe [282] PT-CIO4 , PT-AsFr [287] PT-PKfe", PMcT-C104 , PMeT-PFt [389] and PMeT-SO,SFj- [295]...

Precursor polymers, (I) and (II) of PPV and (in) of PDPV were synthesized by the method of Karasz - et al. This involves the polymerization of a bis-sulphonium salt monomer to a water-soluble sulphonium salt polyelectrolyte precursor polymer which can subsequently easily be converted to PPV or PDPV by thermal elimination. In their work, metal-like conductivities were observed when these polymers were doped with AsFs. Compared to PPV, PDPV has improved stability and can be doped under milder conditions. 

When doped with AsFs, PPV oligomers were reported to have conductivities of about 10 S m [48]. Films prepared by the precursor method can be stretched to give a structure with a high degree of uniform molecular orientation. After doping, the conductivity in the direction parallel to the orientation has been reported to be as high as 2.5 X 10 S [49],... 

The layered guest-host structures that can also develop undergo a structural evolution more reminiscent of the intercalation process in 2D layered materials (e.g., graphites or silicates). In this case, quasi-2D galleries open up between stacked sheets of the polymers chain as shown in Fig. 25.8. This type of ordering has often been reported in structural studies [84-89] using molecular dopants. Systems showing evidence of layered structures include iodine-doped PA [86] and AsF.s-doped PPV [87]. These layered structures may occur either alone or in combination with channel formations [85,89]. 

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