Göran Ahlgren

Composites of conducting polymers: polyacetylene–polypyrrole

Electropolymerization of pyrrole onto polyacetylene (pac) gives conducting composites the morphology of which depends in the initial doping state of the pac.

trans-Perillenal a furanoid monoterpene from pine saw-fly,Neodiprion sertifer (Hymenoptera: Diprionidae)

Volatile constituents present in nanogram quantities in various body parts and glands of the males and females of the speciesNeodiprion sertifer Geoffr. (Hymenoptera: Diprionidae) have been investigated by GC-MS. A significant amount of a volatile constituent was detected in the lateral parts of the integument of abdominal segments II-III. The constituent was identified as the furanoid monoterpenetrans-perillenal (I) previously not known to occur in nature. The identification and synthesis of this compound is described.

Bialkyls from dialkylmetals I. Photochemistry and mass spectra of some (2-cyanoethyl)- and [2-(methoxycarbonyl)ethyl]metals☆

Abstract We have studied the photolysis and the fragmentation in the mass spectrometer of bis(2-cyanoethyl)mercury, bis(2-cyanoethyl) selenide, bis(2-cyanoethyl) sulphide, dibutylbis(2-cyanoethyl)stannane, and bis[2-(methoxycarbonyl)ethyl] selenide. The mercury compound gave a high yield of adiponitrile on photolysis and in the mass spectrometer it gave the fragmentation pattern of adiponitrile, including the molecular ion, as part of the total fragmentation pattern. A low yield of bialkyl was also formed on photolysis of the bis[2-(methoxycarbonyl)ethyl] selenide but no peaks corresponding to biakyl were observed in the mass spectrum. None of the other compounds yielded alkyl dimer. A preliminary discussion of the results in terms of orbital symmetry is presented.

A New Cation Radical Salt: (bMDODBF)2AsF6

Abstract The AsF− 6 cation radical salt of 2,3,6,7-bis-methylene-dioxydibenzofuran has been synthesized. Its structural, electrical and ESR properties are presented.

The electrical and magnetic properties of TMDBFBF4, ClO4, AsF6 and PF6, the cation radical salts of tetramethoxydibenzofuran

The cation radical salts (crs) of tetramethoxydibenzofuran, (TMDBF)X, form non-stoichiometric salts with different anions (X = BF4−, ClO4−, AsF6− and PF6−). All investigated salts contained the solvent used in the electrocrystallization (CH2Cl2). The X-ray investigation showed that the crs were disordered. Conductivity measurements showed that the crs were thermally activated with Δ < 110 meV at high temperatures; at lower temperatures there are different deviations from this behaviour. All crs have σrt ∼ 10−2 (Ω cm)−1. The susceptibilities are large, χ ∼ 10−4 emu/mole, and barely temperature dependent between 300 and 50 K. Below 50 K, χ increases less than 1/T. These results are interpreted using a common model for σ and χ. Due to the quasi one-dimensionality of the crs, the disorder present causes all states to be localized. This leads to charge transport by phonon-assisted hopping between localized states near the Fermi level, and a paramagnetic susceptibility due to antiferromagnetic order in one dimension. Interacting chain segments exist with weak exchanges ϵJ at a random concentration among uniform nearest-neighbour exchanges J. The narrow e.s.r. lines (about 100 mG at room temperature) are caused by exchange narrowing, with an exchange frequency of about 1012 Hz.

Organic metals. Introduction of indium and thallium tetrachloride anions into polyacetylene by anodic oxidation

Polyacetylene films can by oxidized electrochemically in LiCI–MCI3–nitromethane solutions (where M In and Tl) to give highly conducting polymers.

Composites Of Conducting Polymers: Polyacetylene - Polypyrrole

Abstract Pyrrole can be electrochemically polymerised onto polyacetylene anodes. The morphology of the resulting conducting composites depends on the initial doping state (e.g. conductivity) of the polyacetylene. The air and water stability of the conducting composites is excellent compared to doped polyacetylene. Both components conduct the current.

Study On The Electrochemical Doping Of Polyacetylene With Selected Metal Halides

Abstract Electrochemical oxidation has been found to be a convenient method for introduction of tetrachloride anions of Fe, Al, In, T1 into polyacetylene. EPR, Mossbauer spectroscopies and elemental analyses show that oxidation (doping) and reduction (undoping) cycle in (CH)X - L1Cl/MCl3 systems is not totally reversible - and is accompanied by irreversible side reactions which limit possible application of (CH)X - metal chloride systems in energy storage devices.

The influence of water on the degradation of FeCl3-doped polyacetylene

The degradation rate of FeCl3-doped polyacetylene in air and argon is dependent on the water content of the gas phase.

Partially deuterated tetramethoxydibenzofuran-hexafluorophosphate: An electron spin resonance study

Abstract The susceptibility of the title compound is large, χ (300 K) = 3.8 × 10 −4 emu/mol, and the temperature dependence of the susceptibility is explained by the random exchange Heisenberg antiferromagnetic chain model. The localization of the electrons in an antiferromagnetic order is proved by the angular dependence of the e.s.r. linewidth, which corresponds to dipole-dipole interaction. A comparison of the spin properties between the title compound and the non-deurated compound exhibits only minor differences.