The influence of ionic liquid's nature on free radical polymerization of vinyl monomers and ionic conductivity of the obtained polymeric materials

Various 1,3‐dialkylimidazolium and tetraalkylphosphonium ionic liquids (ILs), including novel ones, have been studied as reaction media for free radical polymerization of methyl methacrylate (MMA), acrylonitrile (AN) and 1‐vinyl‐3‐ethylimidazolium salts (ViEtIm⁺)Y^?. The influence of IL's nature upon the polymer formulation was investigated. The use of different ionic liquids allows not only to obtain the polymers with high molecular weight (PMMA, up to 5,770,000 g/mol; PAN, up to 735,000 g/mol and poly[(ViEtIm⁺)Y^?], up to 1,130,000 g/mol) in high yields, but also to control the polymerization rate and molecular mass. The physicochemical characteristics, including mechanical properties, thermal stability and heat‐resistance of the obtained polymers were studied in order to compare with those of polymers prepared in a traditional media. It was found that elongation, tensile modulus and strength of PAN, which was synthesized in ionic liquid, are reliatively higher. The influence of IL's nature upon their ionic conductivity and the formation of conductive polymers from molten‐salt‐type vinyl monomers was investigated. Molecular design of the polymers simultaneously with the influence of IL's nature in order to achieve higher ionic conductivity is discussed. Flexible, transparent polymer films, obtained in different ways, show relatively high ionic conductivity (of about 10^?5 S cm^?1 at 20°C). Copyright © 2006 John Wiley & Sons, Ltd.     

4,5-Dihydroxyimidazolidin-2-ones in the α-ureidoalkylation reaction of N-(carboxyalkyl)-, N-(hydroxyalkyl)-, and N-(aminoalkyl)ureas 1. α-Ureidoalkylation of N-(carboxyalkyl)ureas

Russian Chemical Bulletin - The α-ureidoalkylation of N-(carboxyalkyl)ureas (ureido acids) with 1,3-H2 s-, 1,3-Me 2 s-, and 1,3-Et2 s-4,5-dihydroxyimidazolidin-2-ones was systematically...     

Synthesis and molecular structures of heterometallic complexes [RC5H4Fe(CO)2]2 Sn(TePh)2 and their adducts with chromium and tungsten carbonyls or with trimethylplatinum iodide

Complexes [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂ (R=H, Me) containing stable heterometallic Fe−Sn−Fe fragments with two phenyltellurium groups at the tin atom were synthesized from [RC₅H₄Fe(CO)₂]₂SnCl₂ (R=H, Me) and sodium phenyltelluride and their structures were established by X-ray analysis. Their chelates with tungsten tetracarbonyl, [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂[W(CO)₄] (R=Me, H), and complexes with two Cr(CO)₅ fragments or dimeric trimethylplatinum iodide were synthesized and studied by X-ray analysis. Thermal decomposition of [RC₅H₄Fe(CO)₂]₂Sn(TePh)₂ complexes and their adducts with ML fragments (ML=W(CO)₄, 2 Cr(CO)₅, (Me₃PtI)₂) into inorganic tellurides of a preset mixed-metal—chalcogenide composition was studied by differential scanning calorimetry. The temperature of complete elimination of organic fragments from methylcyclopentadienyl complexes is about 100°C lower than in the case of cyclopentadienyl analogs. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1766–1772, September, 1999.     

Stacking interaction in crystals of a dinuclear rhodium complex with a bridging phenylborole ligand

Russian Chemical Bulletin -     

Nature of weak inter-and intramolecular interactions in crystals 8. Influence of intermolecular contacts on the strength of intramolecular O-H...N bonds in crystals of 3-(2-hydroxyphenyl)-1,2,4-triazoles

The nature and energy of the intramolecular H-bond in 3-(2-hydroxyphenyl)-1,2,4-triazoles was studied by X-ray diffraction and quantum chemical methods. In this system, the conjugation does not additionally contribute to the enhancement of the H-bond energy. The cooperative effects lead to a strengthening of the intramolecular H-bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 396–402, March, 2006.     

Exchange and dative coordinate bonds in binuclear zinc complex

The high-resolution X-ray diffraction study of dizinc bis(pyridine)-bis{[μ₂-(2-oxybenzylidene)amino]-4,6-di(tert-butyl)phenoxide} and the analysis of the structures of related compounds refuted the data on the effect of the exchange or dative mechanism of the metalbridging ligand bond formation on the bond strength and revealed the factors controlling the energy of these bonds.     

Stereoelectronic interactions in the fragment N-C-CN from high-resolution X-ray diffraction data and quantum chemical computations

Analysis of the experimental electron density distribution function for the crystal and quantum chemical calculations revealed some distinctive features of stereoelectronic interactions (SI) in the fragment N-C-CN. The SI-induced changes in the atomic parameters were characterized in terms of the “Atoms in Molecules” theory. These interactions were compared with competitive SI in the fragment N-C-N. The crystal packing in organic cyanides is discussed. According to the data obtained, relatively weak SI in the fragment N-C-CN can be decisive for the molecular conformation in the crystal when there are no strong competitive interactions.     

2-Nitromethyl-2-trichloromethyl-1,3-benzodioxoles and 2-nitromethyl-2-trichloromethyl-1,3-benzoxazolines: Synthesis and structure

A reaction of 1-bromo-3,3,3-trichloro-1-nitropropene with pyrocatechol, o-aminophenol, and their substituted derivatives led to 2-nitromethyl-2-trichloromethyl-1,3-benzodioxoles and 2-nitromethyl-2-trichloromethyl-1,3-benzoxazolines. The structure of the compounds synthesized was established by IR, ¹H and ¹³C NMR spectroscopy with HMQC and HMBC ¹H—¹³C experiments, and X-ray diffraction analysis.     

Synthesis of Diaminophosphonium Salts [Ph2(ArNH)2P]+Br− (Ar = o-MeC6H4, p-MeC6H4, p-Pr i C6H4, p-EtO2CC6H4, p-MeOC6H4)

The behavior of different anilines H₂NC₆H₄R (R = o-Me, p-Me, o-, m- and p? ⁱ Pr, p-OMe, p-CO₂Et) and 2,6-Me₂C₆H₃NH₂ towards trihalophosphoranes was studied. 2,6-Me₂C₆H₃NH₂ failed to form the diaminophosphonium salt [Ph₂PNH(2,6-Me₂C₆H₃)₂]Br, and the aminophosphine oxide Ph₂(2,6-Me₂C₆H₃NH)PO was the only isolated product. Both o- and p-toluidine gave the corresponding diaminophosphonium salts; however in the case of o-toluidine, the yield was low and a mixture with the respective aminophosphine oxide was observed. Anilines containing methoxy and ethoxycarbonyl groups in para-position form the diaminophosphonium salts in reasonable yields.