Nucleophilic addition to acetylenes in superbasic catalytic systems: XV. Vinylation of 2-hydroxymethylfuran

2-Hydroxymethylfuran reacted with acetylene in superbasic catalytic systems MOH-DMSO (M = Na, K) under mild temperature conditions (75–85°C, 1–2 h), yielding 80% of 2-vinyloxymethylfuran. The product, as well as acetaldehyde acetals derived therefrom, turned out to be promising as modifiers for electrolyte in lithium-sulfur rechargeable batteries.     

Synthesis and structure of copper(II) complexes with diaminodioxime (H<Subscript>2</Subscript>L), a derivative of the monoterpenoid (+)-3-carene

Copper(II) compounds with the optically active diaminodioxime (H₂L) derived from the monoterpenoid (+)-3-carene, Cu(H₂L)(NO₃)₂ H₂O (I), Cu(H₂L)(ClO₄)₂ H₂O (II), Cu(H₂L)Br₂ H₂O (III), and Cu(H₂L)SO₄0.5H₂O (IV) with µ_eff equal to 1.81, 1.79, 1.71, and 1.8 µ_B, respectively, were prepared. Studies of the complexes by IR and EPR spectroscopy showed that I and II are mononuclear ionic complexes. Compound III apparently has polymeric structure (the CuN₄Br₂ coordination unit). According to EPR data, the Cu²⁺ ions in polycrystalline compounds III and IV undergo exchange interactions.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 897–900.Original Russian Text Copyright © 2004 by Larionov, Myachina, Sheludyakova, Boguslavskii, Tkachev, Bizyaev.     

Synthesis and properties of polyenic oligosulfides derived from acetylene and elemental sulfur

Oligosulfides derived from ethyne-1,2-dithiol were synthesized in up to 96% yield via insertion of elemental sulfur into the Na-C_sp bond of sodium acetylides (HC≡CNa, NaC≡CSNa) in liquid ammonia, followed by hydrolysis and spontaneous oligomerization of ethynethiols, ethynedithiols, and mono-and bis-(polysulfanyl)ethynes (HC≡CSH, HSC≡CSH, HC≡CS_xH, HS_xC≡CS_yH). The resulting polyenic oligosulfides were isolated as brown powders melting in the temperature range from 122 to 203°C and containing up to 77% of sulfur; they are sparingly soluble in organic solvents and are high-resistance semiconductors (10^?13–10^?14 S cm^?1) possessing paramagnetic (10¹⁷–10¹⁸ spin g^?1) and redox properties. According to the data of IR and ESR spectroscopy and cyclic voltammetry, the oligomers obtained consist mainly of different oligosulfide units, including oligothienothiophene structures. They also ensure a high discharge capacity (345–720 mA h g^?1) of lithium sulfur rechargeable batteries.     

New Electrochemically Active Highly Sulfurized Polyconjugated Polymers

The electrochemical activity of new highly sulfurized polyconjugated polymers is studied. The polymers, polythienothiophene, poly(4,5,6,7-tetrathieno-4,5,6,7-tetrahydro-2,3-dehydrobenzothiophene), poly(6-methylthieno[2,3-b]pyridine-4-thione-5-thiol), and poly(6H-thieno[2,3-b]-azepine-6,7(8H)-dithione) are obtained in a deep sulfurization of polyethylene, polystyrene, and poly(5-vinyl-2-methylpyridine) by elemental sulfur. Employed as active cathodic material in lithium batteries, these polymers ensure their prolonged cycling with specific discharge capacity of up to 339 mA h/g. The effect of the conducting additive and electrolyte on the energy capacity and cycling of polymer cathodes in lithium batteries is discussed.     

Synthesis and structure of optically active compounds [Ni(HL1)]NO3 and [Ni(HL2)]NO3H2O containing anions of diaminodioximes H2L1 and H2L2 derived from α-Pinene and (+)-3-Carene as Ligands

New optically active levorotatory compounds [Ni(HL¹)]NO₃ (I) and [Ni(HL²)]NO₃H₂O (II) containing the anions of chiral diaminodioximes, H₂L¹ and H₂L², derived from the terpenes ±-pinene and (+)-3-carene, respectively, were synthesized. Complexes I and II were studied by X-ray diffraction. The crystal structures of compounds are ionic, being composed of the [Ni(HL¹)]⁺ or [Ni(HL²)]⁺ cations and the outer-sphere NO₃^– anions. The Ni²⁺ ion coordinates four N atoms of the tetradentate chelating ligand, the NiN₄ coordination unit being shaped like a tetrahedrally distorted square. Compounds I and II are diamagnetic, which corresponds to a low-spin d⁸ configuration. The NMR spectra of compounds were recorded and analyzed.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 888–896.Original Russian Text Copyright © 2004 by Larionov, Myachina, Saveleva, Glinskaya, Klevtsova, Sheludyakova, Tkachev, Bizyaev.     

Sulfurization of polymers

Polydiethylsiloxane reacts with elemental sulfur at 300–320 °C (ZnCl₂ slightly accelerates the process) with evolution of hydrogen sulfide and formation of black lustrous paramagnetic powders (sulfur content up to 38.50%), which possess a noticeable electric conductivity (3.20·10⁻⁷ S cm⁻¹ when doped with I₂) and redox properties. Polydimethylsiloxanes are stable under the same conditions. In rechargeable lithium batteries, the sulfurized polydiethylsiloxane behaves as an active cathode material allowing charging and discharging of the battery. The specific capacities of the cathodic and anodic processes (80–100 (mA h) g⁻¹) change insignificantly. The hydrolytic stability, elemental analysis, IR and ESR spectra, DSC-TGA and derivatographic analyses data, the electric conductivity, and the character of the electrochemical activity of the polymers synthesized indicate that the polymers contain the polyvinylene disulfide blocks cross-linked by the polysiloxane chain.     

Synthesis and structure of palladium(II) and copper(II) complexes with chiral bis-α-aminooximes containing (+)-3-carene or (+)-limonene fragments and 4,4′-methylenedianiline linker. Crystal structure of the complex [Cu(i-PrOH)Cl2(μ-H2L3)CuCl2·H2O]

Coordination compounds Pd₂(H₂L²)Cl⁴ (I), Cu₂(H₂L²)Cl₄ (II), Pd₂(H₂L³)Cl₄ (III), and Cu₂(H₂L³)Cl₄ (IV), where H₂L² and H₂L³ are chiral bis-α-aminooxime ligands consisting of (+)-3-carene or (+)-limonene fragments and 4,4′-methylenedianiline linker, were synthesized and examined by NMR, ESR, and IR spectroscopy. The structure of [Cu(i-PrOH)CL₂(μ-H₂L³)CuCL₂·H₂O] (V) was determined by X-ray analysis.     

Synthesis and redox activity of sulfurized poly(methylene polysulfides)

Redox-active sulfurized poly(methylene polysulfides) ?[CH₂S _y ] _n ? (y = 4–22) were prepared by deep sulfurization of poly(methylene di- and trisulfides) with elemental sulfur. The use of the substances obtained as an active cathode material of rechargeable lithium cells ensures their cycling with a specific discharge capacity of 418–550 mA h g^?1.