New multicomponent organic semiconductors based on ET with polymeric Anions: α″-(ET)2N(CN)2·2H2O and α‴-(ET)6(NO3)3·2C2H5O2N3

New multicomponent radical cation salts derived from bis(ethylenedithio)tetrathiafulvalene (ET) were prepared: bis(ethylenedithio)tetrathiafulvalene dicyanamide dihydrate α″-(ET)₂N(CN)₂·2H₂O and bis-(ethylenedithio)tetrathiafulvalene nitrate α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃ containing two biuret molecules (C₂H₅O₂N₃). The crystal structures of the compounds were determined, and their conducting properties were examined. Both salts have layered structures in which radical cation layers alternate with nonconducting anionic layers. The radical cation layers in the salts α″-(ET)₂N(CN)₂·2H₂O and α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃ are packed in the α″ and α? fashion, respectively. Anionic layers consist of polymeric chains formed by hydrogen bonding between [N(CN)₂]? anions and water molecules in α″-(ET)₂N(CN)₂·2H₂O or between NO?₃ anions and biuret molecules in α?-(ET)₆(NO₃)₃·2C₂H₅O₂N₃. Both salts show semiconductor conductivity.     

Tetrafluoroethylene telomers with reactive end groups: radiation-initiated synthesis,properties, and prospects for applications

Russian Chemical Bulletin - The results of studies on radiation-initiated telomerization of tetrafluoroethylene and on the properties of telomers with reactive terminal hydroxyl, amino, and silane...     

The first BETS radical cation salts with dicyanamide anion: Crystal growth, structure and conductivity study

Electrochemical oxidation of bis(ethylenedithio)tetraselenafulvalene (BETS) has been investigated. Simple and complex dicyanamides of transition metals (Mn²⁺, Ni²⁺ and Fe²⁺) were used as electrolytes. The correlation between composition of prepared radical cation salts and metal nature in electrolytes was established. Manganese dicyanamides provide the formation of BETS salts with the {Mn[N(CN)₂]₃}- and [N(CN)₂]-XH₂O anions. When Ni- or Fe-containing electrolytes were used only metalless BETS salts, α″-BETS₂[N(CN)₂]·2H₂O (I) and θ-BETS₂[N(CN)₂]·3.6H₂O (II), formed. Structures and conducting properties of these salts were analyzed. Both salts exhibit layered structure. Conducting radical cation layers have α″ (I)- or θ-type (II). Anion sheets appear as two-dimensional polymer networks of different types. These networks are formed by [N(CN)]₂⁻ anions and water molecules interlinked by hydrogen bonds. Salt I is a semiconductor and II demonstrates resistance drop down to150 K at normal pressure and down to 72 K at ∼0.4 kbar pressure.     

Action of N-hydroxyphthalimide on chain stereoregularity in the radical polymerization of methyl methacrylate

N-Hydroxyphthalimide (NHPI) has a dual function in the radical polymerization of methyl methacrylate (MMA): this compound acts as an initiator and also provides for stereochemical control of the polymer chain. Lowering the polymerization temperature leads to increased syndiotactic specificity in the polymethyl methacrylate molecule. The action of NHPI as an initiator and stereoregulator is attributed to the capacity of this compound to form a hydrogen bond with the monomer molecule and growing macroradical.     

Preparation of hydrogenation catalysts based on platinum nanoparticles supported on carbon nanomaterials

Hydrogenation catalysts as platinum nanoparticles supported on carbon nanomaterials (singleand multi-walled nanotubes, nanofibers, and fullerene black) have been obtained by modifying the platinum precursor with an organic base. A support pretreatment procedure for producing carboxyl groups on the nanotube and nanofiber surface is suggested.     

Photomagnetic effect in molecular magnets based on nitrosyl complexes of ruthenium and rare-earth ions

The magnetic properties of new bifunctional molecular magnets based on nitrosyl complexes of ruthenium and thiacalix[4]arenes of rare-earth ions (Gd³⁺, Dy³⁺) have been investigated. A photoinduced decrease in the magnetization of the molecular magnet with rare-earth ions Gd³⁺ and the absence of a photomagnetic effect in crystals with rare-earth ions Dy³⁺ have been revealed at a temperature of 2 K. It has been found that, in the sample containing Dy³⁺ ions, the magnetization deviates by 6% from the calculated value for noninteracting ions. A comparison of the results obtained for two groups of isostructural samples, which differ only in the type of rare-earth ions, has demonstrated that the observed deviation of the magnetization is caused by the interaction of the orbital moment of the Dy³⁺ ions with the crystal field.     

Organic superconductors revisited

The surfaces of a ten years aged crystal and a freshly prepared κ-(BEDT-TTF)₂Cu(NCS)₂ crystal were compared by scanning tunneling microscopy (STM). The molecularly-resolved STM images of the bc plane of the crystals agree with each other and with the electronic contrast obtained by new density functional theory (DFT) based simulations. Even after ten years STM images of the molecular stacking of BEDT-TTF display a variation in brightness at the positions of different molecules. We attribute this symmetry breaking concerning the brightness in the STM images of the otherwise equivalent BEDT-TTF dimers to the electronic states of a relaxed surface.     

Thermal reduction of graphite oxide derivatives for preparation of supports for platinum hydrogenation catalysts

Thermal reduction of graphite oxide and its derivatives under argon atmosphere has been studied by means of thermogravimetric analysis. Carbon materials prepared via thermal reduction of graphite oxide derivatives in argon at 900°С during 3 h have been used for deposition of platinum from H₂PtCl₆ solutions. Pt particles supported on the support catalyze liquid-phase hydrogenation of nitrobenzene and dec-1-ene under atmospheric pressure of H₂. Thermal reduction of the supports based on graphite oxide results in the formation of the structural defects significantly enhancing the catalytic activity.