Powder conductivities

Over the past decade a number of new covalently bonded TTF/ferrocene adducts have been reported [77, 78]. The crystal structure of the l,l -bis(l,3-dithiole-2-ylidine)-substituted ferrocene derivative has been published [77]. In this complex, ferrocene has essentially been incorporated as a molecular spacer between the two l,3-dithole-2-ylidene rings forming a stretched TTF molecule. This adduct, and its methyl-substituted derivative, have been combined with TCNQ to form charge-transfer complexes with room temperature powder conductivities of 0.2 S cm-1. Similar diferrocenyl complexes have been prepared with bis (dithiolene) metal complexes [79, 80]. 

Semiconducting black polymers characterized as 44 have been prepared via slow heating of triple-decker (allyl)nickel diborolyl triple-decker complexes.44 EXAFS studies reveal an Ni-Ni distance of 3.35 A and a powder conductivity of ca. 10-2 S cm-1. When doped with iodine or oxygen, the conductivity of these polymers... 

The present work deals with soUd CT complexes of phenazines which, in the most favorable cases, include the crystal structure, single-crystal electron spin resonance (epr) data, the temperature dependence of the magnetic susceptibility or of the powder conductivity, and a CT absorption spectrum. We have not pursued complexes that could not be crystallized, nor have we investigated completely similar materials. 

In searching for new conducting solids based on segregated or RR P stacks, the neutral donors were oxidized, in most cases chemically or electrolitically, and combined with non-nucleophilic anions like CIOT, PF, BF, etc. The resulting 1 1 salts with q = 1 were found to have rather low powder conductivities. Our usual doping procedures were not successful for the inorganic RR P salts. Some of the analytically and structurally identified species are summarized in Table 6. 

Dry bulk resistivity, O-cm 0.005-0.008 (silver-coated products of PQ), 0.0017 (silver coated solid and hollow glass spheres - Conduct-O-Fil), 0.004 (silver coated glass fiber - Conduct-O-Fil), 0.0005-0.0006 (silver coated copper powder - Conduct-O-Fil), 0.0012 (silver coated copper flake - Conduct-O-Fil), 0.0007 (silver coated aluminum sphere - Conduct-O-Fil), 0.003 (silver coated inorganic flake - Conduct-O-Fil), 0.006 (silver coated nickel granules - Conduct -O-Fil), 0.0000016 - pure silver... 

In this article, we will not describe in detail the experimental equipment used to determine the optical, electronic, and magnetic properties of these materials. Standard instruments were used for EPR,ENDOR. solid-state NMR. SQUID susceptibility, powder conductivity, optical reflectance and transmittance, and DSC. although some home-built instruments were involved. The specific equipment used is described in the references. The major consideration in designing and using equipment is the need to keep the samples cold and away from air and moisture at all times. 

Figure 8.22 shows the change of hydrodynamic radius of PPy-DBSA in chloroform containing different amounts of extra DBSA [68]. The hydrodynamic radius of PPy-DBSA with the powder conductivity of 1 S/cm increased from 27 to 40 nm when the concentration of extra DBSA was increased from 0.02 to 0.5 g/dL. Further increase of the extra DBSA concentration beyond 1 g/dL resulted in the saturation of the hydrodynamic radius of PPy-DBSA at around 45 nm. 

Feed Composition (DBSA/PAMPS) Yield (%) Powder Conductivity (S/cm) Film Conductivity (S/cm) Solubility in Chloroform... 

The room temperature powder conductivities of the compounds described in this section are summarized in Table 7. 

Table 6.8 lists some thermal conductivities of evacuated powders used in large Dewars for LH2. Since the dielectric powders are transparent to room temperature radiation, the effectiveness of the powders can be increased significantly by the addition of metal powders (e.g., Al, Cu, Ag) which reflect the radiation. Since the metal powders conduct, their addition is an optimum at certain levels. 

Table 15.2 Room Temperature Powder Conductivities of Undoped and Doped [MacML],...

The powder conductivities of a selection of monomeric and bridged macrocycles (mostly phthalocyanines) in the nondoped state are listed in Table 15.6. All the bridged complexes [MacM(L)J (M = Fe, Ru, Os L = pyz, tz, dabco) consist of cofacially arranged macrocycles that are separated by approximately the same distance (about 600 pm) (see Fig. 15.12). 

As of 1996, the production plant at Monsanto was still pilot-scale. Typical properties of Versicon were Compacted powder conductivity 4 S/cm, moisture 4% w/w, particle size 3 - 100 /i, density 1.36 g/cc, surface area 5-20 m /g. Also produced on a pilot scale by Monsanto was a "soluble P(ANi) , a green liquid which is a blend of 50% colloidal P(ANi), 40% xylenes and 10% butyl cellulose. P(ANi) was at one time also marketed by AmeriChem, Inc., Cleveland, OH, USA, in collaboration with Monsanto, and by PolySciences Inc., Pittsburgh, PA, USA. Other dispersions of P(ANi) in PVC, Nylon-12, and other thermoplastics were also, in the mid-1990 s, in the test marketing stage in collaboration with Zipperling Kessler Co.. 

Oxidative doping of PcM, e.g. with iodine, often results in highly increased conductivities of the poly crystalline samples. Undoped PcNi (j8-modifica-tion. Figure 13.15b) shows a powder conductivity of 10 S/cm, whereas PcNil (formed by iodine doping) exhibits a powder conductivity of 0.7 S/cm [102]. For many doped, especially iodinated, metal complexes the crystal structure is known. Depending upon the... 

Table 13.2 Room temperature powder conductivities of undoped and doped [MacML] [14]...

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