Synthesis of a new donor, BEDT-HBDST and crystal structures, electrical and magnetic properties of (BEDT-HBDST)2MX4 (M=Fe, Ga, X=Cl, Br), where BEDT-HBDST=2,5-bis(4,5-ethylenedithio-1,3-diselenol-2-ylidene)-2,3,4,5-tetrahydrothiophene

A novel conjugation-elongated bis(ethylenedithio)tetraselenafulvalene (BETS) type donor, 2,5-bis(4,5-ethylenedithio-1,3-diselenol-2-ylidene)-2,3,4,5-tetrahydrothiophene (BEDT-HBDST) and its magnetic and non-magnetic anion salts, (BEDT-HBDST)₂MX₄ (MX₄⁻=FeCl₄⁻, GaCl₄⁻, FeBr₄⁻ and GaBr₄⁻), were prepared. These four salts are isostructural and belong to the space group of P2/c. They showed semiconducting behavior with small activation energies (59-64 meV). The band structures of these salts are quasi one-dimensional and there is a midgap between the upper band and the lower band, since the degree of dimerization is significant in the stacking direction. The MX₄⁻ ions are located between the donor columns and near to the ethylenedithio moieties of the donor molecules. The magnetic susceptibilities of the FeCl₄⁻ and FeBr₄⁻ salts follow the Curie-Weiss law with Curie constants of 4.6 and 4.8 emu K mol⁻¹ (sum of the spins of S=5/2 and S=1/2) and negative Weiss temperatures of θ=−1.2 and −4.9 K, respectively, revealing a weak antiferromagnetic interaction of 3d spins of the FeCl₄⁻ and FeBr₄⁻ anions. The Fe?Fe (6.66-7.60 Å), Cl?Cl (4.81-4.82 Å) and Br?Br (4.74-4.77 Å) distances in the crystal structures of these salts are significantly long. Therefore, the direct magnetic interaction between the 3d spins of the nearest neighboring Fe³⁺ ions appears to be not readily accessible.     

New organic metals: Radical cation salts of bis(ethylenedioxo)tetrathiafulvalene with halide mercurate anions

Radical cation salts with halide mercurate anions were obtained by the electrochemical oxidation of bis(ethylenedioxo)tetrathiafulvalene (BEDO-TTF), and their conductivity was studied. The compounds (BEDO-TTF)₄Hg₃X₈ (X = Cl or Br), (BEDO-TTF)₄Hg_3.5I₉, and (BEDO-TTF)₂HgBr₃ possess the conductivity of the metallic type down to helium temperatures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1167–1170, May, 1996.     

Acid-catalyzed attack of the dinitrogen ligand in thecis-(Me2PhP)4Mo(N2)2 andtrans-(Ph2PCH2CH2PPh2W(N2)2 complexes by nitronium and nitrosonium cations with the formation of nitrogen oxides

The interaction of labeled dinitrogen complexescis-(Me₂PhP)₄Mo(¹⁵N₂)₂ andtrans-(dppe)₂W(¹⁵N₂)₂ with non-labeled nitronium and nitrosonium fluoroborates,¹⁴NO₂BF₄ and¹⁴NOBF₄, in sulfolane at room temperature in the presence of H₂SO₄ results in rapid formation of labeled nitrous and nitric oxides (¹⁵N¹⁴NO,¹⁵NO), as well as¹⁵N¹⁴N. The yield of the products depends on the reagent ratio and reaches 10–20 mol. % per mole of a complex under optimum conditions. The mechanism of the reactions found is proposed. It involves the step of protonation of the dinitrogen ligand to form the corresponding hydrazido(2–) derivatives, which are then attacked by nitronium or nitrosonium cations. In accordance with the mechanism proposed, it was established that the hydrazido(2–) complexes, (Me₂PhP)₃Mo(¹⁵N₂H₂)Cl₂ and (dppe)₂W(¹⁵N₂H₂)Cl₂, are capable of forming¹⁵N¹⁴NO,¹⁵NO, and¹⁵N¹⁴N under the action of¹⁴NO₂BF₄ and¹⁴NOBF₄ in the absence of an acid.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 13–13, July, 1995.     

Interfacial tension and fluorine evolution on a carbon anode

During electrolysis of molten KF-2HF, strongly adherent fluorine bubbles are generated at the surface of carbon anode. The current was passing even if the horizontal anode was fully covered with gas film. The formation and growth of gas bubbles were studied by transient electrochemical techniques. It was observed that the fluorine bubbles do not have the spherical cap shape predicted by the classical theory. The curvature radius of the interface profile is not constant, the edge of the bubble being flat with a contact angle close to zero. The results are interpreted in the frame of a model which takes into account the predominant role of the interfacial properties.     

甲基锍盐的合成

在四氟硼酸银存在下，分别以硫醚、硫醇、硫酚或过硫醚为原料与碘甲烷反应制备了相应的甲基锍盐。用１ＨＮＭＲ和１３ＣＮＭＲ表征产物的结构并提出了反应的机理。     

Investigation of the behavior of arenediazonium salts with olefins in BmimPF6

The palladium-catalyzed reactions of olefins with arenediazonium salts in ionic liquids were investigated. For methyl acrylate and methyl acrylonitrile, normal Heck cross-coupling products are obtained in good yields. However, highly selective dimerization products are formed in excellent yields for styrenes. The catalyst system can be recycled.     

The discovery of two kinds of ion pairs

The discovery and implications of the existence of two kinds of ion pairs in solutions of carbanion salts is described. Also discussed are the factors controlling tight–loose ion pair equilibrium: the nature of the carbanion and its counterion, temperature, pressure, solvent, and cation‐complexing additives. A few examples are presented of the effect of these ionic species on the mechanisms of anionic polymerization and proton transfer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3655–3667, 2004     

N-alkoxy-pyridinium and N-alkoxy-quinolinium salts as initiators for cationic photopolymerizations

The polymerization of n-butyl vinyl ether (BVE), cyclohexene oxide (CHO) and 3,4-epoxycyclohexyl(methyl)-3′,4′-epoxycyclohexane carboxylate (EEC) was initiated upon UV irradiation (λ_inc > 300 nm) of dichloromethane solutions containing N-ethoxy-2-methylpyridinium ( V ), N-ethoxy-4-phenyl-pyridinium ( VI ) or N-ethoxy-isoquinolinium hexafluorophosphate ( VII ). Whereas the bifunctional EEC was converted into an insoluble gel, BVE and CHO formed polymers of molar mass: M_w = 2 X 10⁴?2 X 10⁵ (PCHO) and M_w ≈ 2 X 10⁴ (PBVE). Protons are formed with a rather high quantum yield [ø(H+) = 0.48 on irradiating VII in dichloromethane; titration with sodium p-nitrophenolate] and it is, therefore, assumed that the polymerization is initiated by photochemically generated protons. © 1992 John Wiley & Sons, Inc.     

Electron-transfer in molecular functional materials

We discuss electron-transfer processes that govern the physics of several materials or systems of interest for advanced applications. The discussion touches upon several topics, ranging from solvatochromism to solvent-induced symmetry breaking, from excitonic to cooperative effects in molecular crystals, from phase transitions to vibrational contributions to the dielectric constant in organic materials, from spectroscopy to molecular transport. In all these diverse systems electron transfer (ET) plays a major role and is discussed with reference to simple models for delocalized charges.     

Condensed rare-earth metal-rich tellurides. Extension of layered Sc6PdTe2-type compounds to yttrium and lutetium analogues and to Y7Te2, the limiting binary member

Six isotypic R₆ZTe₂ phases have been synthesized in Ta at elevated temperatures and characterized by single crystal X-ray refinements for R=Y, Z=Rh, Pd, Ag, Y and for R=Lu, Z=Cu, Ag. All crystallize in the Sc₆PdTe₂-type structure, Pnma, Z=4, a∼21.5 Å, b∼4.1 Å, c∼11.4 Å. The results can be viewed as the replacement of Te3 atoms in the parent isotypic Sc₂Te (or in the hypothetical Y₂Te or Lu₂Te analogues) by the above the Z, the Y example giving the new binary phase Y₇Te₂. The shorter (and stronger) metal-metal bonds concentrate in the region of metal (Z, Y) substitution, as revealed by larger integrated crystal orbital Hamilton population (ICOHP) values derived from linear muffin-tin-orbital (LMTO) calculations. Partial densities-of-states data for Y₇Te₂ reflect a similar behavior. Individual R-R bond distances are seen to deviate appreciably from the more fundamental overlap population measures for each.