Glycoconjugates of amines: alkylation of primary and secondary amines withN-chloroacetyl-β-glycopyranosylamines

Efficient monoalkylation of a series of primary and secondary amines was demonstrated with the use ofN-chloroacetylglycosylamines derived fromd-glucose,d-galactose,d-mannose,N-acetyl-d-glucosamine, and lactose. The reaction was shown to be useful for incorporation of carbohydrate residues into physiologically active compounds. Glycoconjugates of some derivatives of piperazine, 2-phenylethylamine, tryptamine, and important biogenic amines (norephedrine, octopamine, dopamine) were prepared. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 6, pp. 1244–1247, June, 1998.     

The structure of the dinitromethyl anion in aromatic and heterocyclic compounds

It is shown experimentally that in salts of dinitromethyl derivatives of aromatic and heterocyclic compounds the nitro groups are equivalent, and participate equally in anion formation. It is shown that both in the free state, and as an anion, the dinitromethyl group in aromatic and heterocyclic compounds has just the same spectral characteristics as in aliphatic compounds. These characteristics can be utilized for analytical purposes. The IR spectra do not reveal conjugation between the mono- or dinitromethyl group and the benzene ring. Judging by the UV spectra the benzene ring is not conjugated with the dinitromethyl anion. It is found that in the solid state 2-dinitromethylpyridine is an internal salt.     

Synthesis of elastomeric polypropylene in bulk using C 1-symmetric ansa-metallocenes. New aspects of the synthesis of 1-(fluoren-9-yl)-2-(2-methyl-5,6-dihydrocyclopenta [f]-1H-inden-1-yl)ethane and complexes of zirconium and hafnium with this ligand

Isomeric 1-(fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-1 H-indenyl) ethanes 1a,b and C ₁-symmetric metallocenes, viz., rac-1-(η⁵-fluoren-9-yl)-2-(2-methyl-5, 6-dihydrocyclopenta [f]-η⁵-inden-1-yl) ethanezirconium dichloride (9) and rac-1-(η⁵-fluoren-9-yl)- 2-(2-methyl-5, 6-dihydrocyclopenta [f]η⁵-inden-1-yl)ethanehafnium dichloride (10), with these ligands were synthesized by modified procedures. The structures of compounds 1b (two crystalline modifications) and 10 were established by X-ray diffraction analysis. The synthesis of polypropylene (PP) in bulk was studied in the presence of polymethylalumoxane-activated metallocenes 9 and 10 in the temperature range of 30–70°C. It was demonstrated that triisobutylaluminum can be used as a cocatalyst. In this case, the molecular weight of PP increases by a factor of ∼2. An increase in the reaction temperature leads to an increase in stereoregularity and crystallinity of PP. The polymer synthesized at high temperatures crystallizes in the γ form. The resulting PP is characterized by a wide range of properties from rigid crystalline thermoplastic to amorphous elastomeric. Samples, which have a high molecular weight and moderate isotacticity, exhibit high elastomeric and durability properties.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 400–413, February, 2005.     

Structure of phosphororganic compounds. XL. X-ray structural investigation of 1-tert-butyl-2, 4--bis(tert-butylamino)-4-methyl-1, 2λ3, 4λ5- azadiphosphetidine Iodide

For Communication XXXIX, see [1].     

Oxidation of (η5-6-exo-cyclopentadienylcyclohexadienyl)- (η5-cyclopentadienyl) iron by trityl hexafluorophosphateby trityl hexafluorophosphate

Oxidation of the cyclohexadienyl complex Fe(η⁵-C₅H₅)(1-5-7⁵-6-exo-C₅H₅-C₆H₆) (2) by (Ph₃C)PF₆ (CH₂Cl₂, from −30 to +20 °C) occurs as two concurrent processes: elimination of an H atom from the cyclohexadienyl ligand and replacement of an H atom in the cyclopentadienyl ring by a CPh₃ fragment. A mixture of cationic complexes [Fe(η⁵-C₅H₅) (η⁶-Ph-C₅H₅]⁺ (1⁺) and [Fe(η⁵-C₅H₄CPh₃) (η⁶-Ph-C₅H₅]⁺ (4⁺) (4 ⁺) with PF₆ ⁻ anions is obtained. Deprotonation of the mixture of 1⁺ and 4⁺ complexes under the action of Bu ^t OK inm-xylene followed by boiling of the reaction mixture gives phenylferrocene (7) as the product of η⁶:η⁶ haptotropic rearrangement. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, NO. 5, pp. 1045–1047, May, 1997.     

2-Nitroguanidine Derivatives. New Synthesis of 5(3)-Substituted 3(5)-Nitroamino-1,2,4-triazoles

Russian Journal of Organic Chemistry -     

Inhibiting effect of fullerenes C<Subscript>60</Subscript> and C<Subscript>70</Subscript> on high-temperature oxidative degradation of copolymers of methyl methacrylate with methacrylic acid and methacrylamide

The inhibiting effect of fullerenes on thermal oxidative degradation of copolymers of methyl methacrylate with methacrylic acid and methacrylamide at 340°C was studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 12, 2004, pp. 2047–2049.Original Russian Text Copyright © 2004 by Troitskii, Khokhlova, Konev, Denisova, Novikova.     

Collision-induced nonadiabatic transitions in the second-tier ion-pair states of iodine molecule: experimental and theoretical study of the I2(f0g+) collisions with rare gas atoms

Nonadiabatic transitions induced by collisions with He, Ar, Kr, and Xe atoms in the I(2) molecule excited to the f0(g)(+) second-tier ion-pair state are investigated by means of the optical-optical double resonance spectroscopy. Fluorescence spectra reveal that the transition to the F0(u)(+) state is a dominant nonradiative decay channel for f state in He, Ar, and Kr, whereas the reactive quenching is more efficient for collisions with Xe atom. Total rate constants and vibrational product state distributions for the f-->F electronic energy transfer are determined and analyzed in terms of energy gaps and Franck-Condon factors for the combining vibronic levels at initial vibrational excitations v(f)=8, 10, 14, and 17. Quantum scattering calculations are performed for collisions with He and Ar atoms, implementing a combination of the diatomics-in-molecule and long-range perturbation theories to evaluate diabatic PESs and coupling matrix elements. Calculated rate constants and vibrational product state distributions agree well with the measured ones, especially in case of Ar. Qualitative comparison is made with the previous results for the second-tier f0(g)(+)-->F0(u)(+) transition in collisions with I(2)(X) molecule and the first-tier E0(g)(+)-->D0(u)(+) transition induced by collisions with the rare gas atoms.     

Chronopotentiometric Method of Studying Electroosmosis in Systems with Ion-Exchange Membranes and Lysine Solutions

A new method of chronopotentiometric study of electroosmotic water transfer in the electromembrane system containing amino acid solution is elaborated. An electrodiffusion problem, which allows for a convective solvent transfer in the system, is formulated and solved. By comparing calculated and experimental transition times for MK-40 and MF-4SK cationite membranes in lysine monohydrochloride solutions, the electroosmotic permeability of the membranes and transport numbers of water through them are calculated. A considerably higher electroosmotic water transport through MK-40 as compared with MF-4SK is attributed to differences in their nature and structure.     

Influence of the synthesis conditions of emulsion poly(methyl methacrylate) on the surface structure of the specimens

The surface structure of poly(methyl methacrylate) specimens prepared by emulsifier-free emulsion polymerization of methyl methacrylate was examined in relation to the synthesis conditions (pH of the medium, initiator concentration, and addition of organosilicon compounds).