Bromine, doping

Finally, Eklund s group has described double-walled nanotubes (DWNT), with ca. 0.7 nm inner diameter and 1.4 nm outer diameter, that can form a three-layer cylindrical capacitor with a shell of bromine anions forming the outer electrode. Holes segregate on the outer nanotube, and saturation bromine doping creates 1 hole per 26 carbon atoms in the DWNT [135]. 

Vinylcarbene is known to close to cyclopropene.59 The reverse reaction is also possible Triplet-propene-l,3-diyl (frans-T-33 ) can be generated from cyclopropene 32 by irradiation in a bromine-doped xenon matrix at 10 K 1-methylcyclopropene (34) yields triplet-2-butene-l,3-diyl (Iruns-T-SS ).60-62 The concentration of 35 under these conditions is high enough to be able to detect this diradical IR spectroscopically. The experiments suggest that even the parent vinyl carbene 33 is detectable.61,62 Calculations ((U)B3LYP/6-31G )61,62 not only allow the comparison of theoretical and experimental IR spectra but also... 

Advantage has been taken of organometallie complexes with long-chain alkyl-ammonium or pyridinium salts to increase the dimensionality and, hence, the lateral conductance [746, 747]. Indeed, the highest reported room temperature conductivity to date (25 Scm ) was measured in bromine-doped LB films prepared from tridecylmethyl-ammonium Au-(dmit)2 [741, 742],... 

Experimentally, surface-segregation effects were shown by Ghosal et al. (2000) who studied the surfaces of bromine-doped NaCl solids (the Br/Cl ratio was 33 times higher than that of seawater) by X-ray photoelectron spectroscopy. They found that bromine was predominantly present at the surface. Zangmeister et al. (2001) confirmed this result by using a variety of experimental techniques and a range of Br/Cl ratios that covers that of seawater. However, both experiments were performed on solid salts. 

Ghosal S., Shbeeb A., and Hemminger J. C. (2000) Surface Segregation of Bromine doped NaCl implications for the seasonal variations in Arctic ozone. Geophys. Res. Lett. 27, 1879-1882. 

The properties of such apparently soluble materials differed greatly from those containing stabilized polyacetylene crystallites. Attempts to dope the soluble copolymers yielded materials with low conductivities, and chemistry typical of solution chemistry (bromination) was observed rather than the formation of a stable bromine-doped polyacetylene phase. A poly(isoprene-fo-acetylene) copolymer oxidized with iodine gave conductivities as high as 1-10 S/cm, but the characterization of the copolymer was insufiScient to unambiguously identify it as a soluble copolymer. On the basis of previously reported work, this material is likely to correspond to a stabilized suspension rather than a solution. 

DBEDOT (0.01-2 g) was incubated at 60 °C for 24 h and dried in vacuo (0.1 mbar) at room temperature to give black crystals of bromine-doped PEDOT. 

Oyanagi H, Tokumoto M, Ishiguro T, Shirakawa H, Nemoto H, Matsusita T, Ito M, Kuroda H (1984) Polarized X-ray absorption spectra of bromine doped polyacetylene evidence for highly-oriented polybromine ions. J Phys Soc Japan 53 4044-4053 Pauling L (1960) The Nature of the chemical bond. Cornell Univ. Press, Ithaca, NY Perera RCC, Barth J, LaVilla RE, Deslattes RD, Henins A (1985) Multivacancy effects in the X-ray spectra of CH3C1. Phys Rev A 32 1489-1494... 

Bromine-doping of condensed bithiophene layers is reported by Ramsey et at. [223]. In the UPS spectra a shift towards the Fermi level, a new 4.3 cV emission, and some smaller changes in the intensities of the upper two 7t-bands are observed. The ELS (electron energy loss) spectra reveal two transitions at 2 eV and 1.2 eV attributed to absorptions due to the presence of polaron states and a gap state excitation al 2 eV for higher dopant concentrations due to bi-polaron formation. 

Bisemi, M., A. Marinangeli, and M. Mastragostino. 1986. Bromine doped polydithienothiophene A cathode-active material in aqueous medium. Electrochim Acta 31 1193. 

In much the same way, triplet but-2-ene-l,3-diyl (67 R = Me) was generated on UV-irradiation of 1-methylcyclopropene (66 R = Me) in bromine-doped Xe matrices and was characterized by IR spectroscopy. " Under similar conditions, cyclopropene seemed to yield propene-l,3-diyl (67 R = H), although the interpretation of the spectral data was less certain in this case. Theoretical calculations accorded with the experiments in predicting that formation of the diyls is the lowest energy ground-state pathway for ring opening of each of the cyclopropenes. 

As in the case of cyclopropane (see Section 15.3), cyclobutane does not absorb at wavelengths in the normally accessible UV region of the spectrum and is photostable in argon matrices. Nevertheless, cyclobutane was found to undergo photoinduced reactions in bromine-doped xenon matrices when irradiated with a low-pressure Hg arc (254 nm) and even in undoped xenon, provided a KrF laser (248 nm) was used. The main products were found to be but-l-ene and ethene, although in the doped... 

Maier, G. and Senger, S., Fragmentation of cyclobutane in a bromine-doped and undoped xenon... 

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