Study on the Solvent Extraction with Radio-Tracers. I. Extraction Study on Protactinium-233 with the Noyltrifluoroacetone

Protactinium-233, separated from the irradiated thorium, was used as a tracer for the extraction study with thenoyItrifluoroacetone. From the results obtained by the variation of acidities of HCl with the constant concentration of TTA in benzene, a slope of ?2 was obtained by plotting the distribution coefficients against acidities. With a definite acid concentration of HCl in the aquous solution and by the variation of TTA concentration, a slope of 4 was obtained by plotting the distribution coefficients against the concentration of β-diketone. With these results, species extracted by the organic layer was assumed to be Pa[TTA]₂[HTTA]₂. If the composition of the organic layer was changed by the addition of the following solvents into the TTA in benzene solution, the order of the extraction was found as follows: n-amyl alcohol > cyclohexane > chloroform > n-hexane > carbon tetrachloride > benzene > nitrobenzene > hexone > cyclohexanone > n-butyl alcohol.     

Pyrylocyanines. 31. Benzopyrylocarbocyanines with bridged groupings in the chromophore

4,4-Tetramethylene- and 4,4-pentamethylenebisflavylium salts and their sulfur- and selenium-containing analogs were synthesized. Trimethinecyanine dyes with ethylene and trimethylene bridged groupings in the chromophore were obtained from these salts. The factors that affect the color of these dyes were analyzed thoroughly.For Communication 30 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1319–1323, October, 1993.     

Pyrylocyanines. 33. Pyrylocarbocyanines with bridge groups in the chromophore

Salts of 4,4-tetra-, penta-, and hexamethylene-bis-(2,6-diphenylpyrylium) and -thiopyrylium were synthesized and used as the basis for producing trimethylcyanines with ethylene, tri- and tetramethylene bridge groups in the chromophore. Factors influencing the color of these dyes were analyzed. The bis-pyrylium salts were converted to derivatives of pyridine, N-methyl- and N-phenylpyridinium. The structure of the compounds obtained was confirmed by the data of electron spectroscopy and PMR spectroscopy.For communication 32, see [1].Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev 252660. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1186–1190, September, 1994. Original article submitted July 13, 1994.     

Correlation of the prigogine-flory theory with isothermal compressibility data. I. Systems with quasi-spherical molecules

The isothermal compressibilities K_T for cyclohexane + benzene, cyclohexane + toluene and benzene + toluene systems at 25, 35, 45 and 60°C have been used to test the Prigogine-Flory theory using Van der Waals and Lennard-Jones energy potentials. Flory's energy parameter X ₁₂ was calculated for these systems at the four temperatures. From X ₁₂ for the equimolar mixture, the following excess functions were calculated: (?V^E/?_p)_T which is related to K _T ^E , the heat of mixing H ^E , and the excess volume V ^E . The theory and any of the two potentials give (?V^E/?_p)_T which fit the experimental data, but H ^E and V ^E , calculated using the same X ₁₂ parameter, depart appreciably from the experimental data even though they agree in sign and have the essential features of the excess functions. The departure is apparent in both magnitude (in particular for the cyclohexane + benzene, and cyclohexane + toluene systems) and in the temperature dependence. The conclusion is that the X ₁₂ parameter does not predict the thermodynamic properties of these systems and the Lennard-Jones potential, involving a more complicated expression, does not contribute any improvement over the Van der Waals potential.     

Transition metal Complexes with the Thiosemicarbazide-based Ligands. VI. Nickel and zinc complexes with S-alkylisothiosemicarbazides

The reaction of warm ethanolic solution of Ni(OAc)₂ · 4 H₂O with S-alkylisothiosemicarbazide-hydrogeniodide (L? R · HI; R = Me, Et, n-Pr, n-Bu) and pyridine yielded the octahedral bis(ligand) complexes of the general formula [Ni(L? R)₂Py₂]I₂. By the isothermal heating at 95 and 110°C, these complexes were transformed into the square-planar [Ni(L? R)₂]I₂ (R = Me, Et) complexes and the [Ni(L? R)₂I₂] (R = n-Pr, n-Bu) complexes of distorted octahedral configuration. Besides, the Zn(L? Me)₂I₂ complex was prepared. The compounds have been characterized by elemental analysis, magnetic measurements, diffuse reflectance spectra and TG analysis.     

Surface modification of polymers. II. Grafting with glycidyl acrylates and the reactions of the grafted surfaces with amines

The surface of low density polyethylene has been grafted with glycidyl acrylate and glycidyl methacrylate by photoinitiation. ESCA measurements on the grafted surface showed a 72% coverage for glycidyl acrylate and 52% for glycidyl methacrylate after 10 min of grafting with UV irradiation. ATR–IR showed a 10 times more extensive grafting for glycidyl acrylate than for glycidyl methacrylate after 10 min of grafting, indicating reaction to deeper layers. Acetone and ethanol were used as solvents: acetone yielded slightly more grafting at the surface. The grafted surfaces were reacted with 2M solutions of aniline and propylamine in ethanol. After 4 h reaction at 60°C, with aniline 52% of the epoxy groups while for propylamine 96% of the groups were consumed, as measured with ATR–IR.     

Fluorinations with complex metal fluorides. Part 7. Fluorinations of the methyl pyridines with caesium tetrafluorocobaltate

4-Methylpyridine passed over caesium tetrafluorocobaltate at 330 – 340° gave tridecafluoro(1,3-dimethylpyrrolidine) (1) and its 3-difluoromethyl analogue (2), together with a range of polyfluoro-4-picolines (4 – 10) with ?CF₃, ?CHF₂ or ?CH₂F groups in the 4-position. 3-Methylpyridine similarly gave 1 and its 1,2-isomer (11) together with several polyfluoro-3-picolines (14 – 18). 2-Methylpyridine at 270° gave tridecafluoro(1-ethylpyrrolidine) (13), a trace of 11 and 2-trifluoromethyl- (22), 2-difluoromethyl- (23) and 2-fluoromethyl-tetrafluoropyridine (24); there were also products arising by loss of methyl. Other unidentified fluoroalkylpyridines besides those isolated were present in each case.     

Substitution reactions with the participation of organoaluminum compounds. 7. Reaction of organoaluminum compounds with monochlorodimethyl ether

Conclusions The reaction of monochlorodimethyl ether with different organoaluminum compounds is only a convenient method for the isolation of alkyl methyl ethers in the case of trialkylalanes.For previous communication 6, see [12].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 425–428, February, 1988.     

Ammonia in the ion source. II. Clustering with aromatic nitro compounds

Under positive ion chemical ionization conditions with ammonla at relatively low pressure, aromatic nitro compounds do not form [M + H]⁺ ions but often form ionic clusters [M + NH₄]⁺ and [M + N₂H₇]⁺. Nitrobenzene forms a cluster [2M + NH₄]⁺ and aniline, formed by nucleophilic substitution, leads to a cluster [anilinium ion + nitrobenzene]⁺. The dinitrobenzenes form [M + NH₄]⁺ clusters and show evidence of nitroaniline formation and clustering. 1,3,5-Trinitrobenzene gives little indication of clustering or of substitution. The six isomers of trinitrotoluene appear to be stabilized by the methyl group and form clusters up to [M + N₃H₁₀]⁺. Nucleophilic substitution leads to dinitrotoluidines, which also form clusters with ammonium ions.     

Cyclization of N-alkylazinium cations with binucleophiles. 8. Annellation of the imidazole ring with pyrazines and quinoxalines

Monosubstituted and N,N′-disubstituted thioureas enter into cyclization with pyrazinium and quinoxalinium ion to form imidazo[4,5-b]-annellated pyrazines and quinoxalines.     

On the chemical reaction of matter with antimatter.

A chemical reaction between the building block antiatomic nucleus, the antiproton (p or H- in chemical notation), and the hydrogen molecular ion (H2+) has been observed by the ATHENA collaboration at CERN. The charged pair interact via the long-range Coulomb force in the environment of a Penning trap which is purpose-built to observe antiproton interactions. The net result of the very low energy collision of the pair is the creation of an antiproton-proton bound state, known as protonium (Pn), together with the liberation of a hydrogen atom. The Pn is formed in a highly excited, metastable, state with a lifetime against annihilation of around 1 micros. Effects are observed related to the temperature of the H2+ prior to the interaction, and this is discussed herein.     

Specific interactions including imidazolium andN-methylimidazolium lons. I. Interactions with the picrate anion

The conductances of solutions of methylimidazolium and imidazolium picrate (MeImHPic and ImHPic) in nitrobenzene-benzene mixtures (27.2–. These triple ions are highly stabilized by the hydrogen bond between the second NH group of the ion pair and the second picrate ion. Values of the formation constants for the ion pair ImHPic and for the triple ion PicImHPic^– have been calculated and are discussed.     

Polar bonded phase with the zwitterionic sulfobetaine functional group. Comparison to silica.

A new bonded phase has been prepared by the reaction of n-propylsultone with dimethylaminopropylsilane-modified silica. The resulting functional group is the zwitterionic ammonium propane sulfonate. Chromatographic solvents based on three strong solvents, methylene chloride, diisopropyl ether and acetonitrile, were prepared in hexane. Solutes, including substituted benzenes, polycyclic aromatic hydrocarbons and low-molecular-weight species commonly used as solvents, were chromatographed on the zwitterionic phase and on silica from the same supplier of the dimethylamino phase. The zwitterionic phase is a weaker adsorbent than silica and retentions are less influenced by the type of strong solvent employed, compared to silica. The retention (log k') of solutes on the zwitterionic phase is highly correlated with the free energy of transfer of solute from the vapor phase to water.     

Metal Complexes with Macrocyclic Ligands. XI. Ring size effect on the complexation rates with transition metal ions

The 12-16 membered tetraazamacrocycles 1 - 6 were synthesized, their protonation constants and complexation kinetics measured at 25° and I = 0.50. The results of Table 1 Show that pK is strongly influenced by the ring size whereas pK and pK are relatively insensitive to it. This can be understood in terms of electrostatic interactions of the positive charges when located on adjacent amino groups. The kinetics of complex formation between the macrocyclic ligands and several transition metal ions have been studied by pH-stat and stopped-flow techniques and the results have been analyzed as bimolecular reactions between the metal ion and the different protonated species of the ligands. The rate constants, given in Table 2, show that the macrocycles react less rapidly than analogous open chain amines. However, for a given protonated species of the ligand the rate of complexation follows the order Cu²⁺ > Zn²⁺ > Co2⁺ > Ni²⁺ which parallels the sequence of their water exchange rates. For the diprotonated tetraamines LH reacting with Cu²⁺ the slower rates seem to be mainly a consequence of electrostatic interactions, since a correlation between logk and pK exists. For LH⁺, however, the complexation rates of a metal ion with the different macrocycles are all in one order of magnitude and do not depend in a regular way on the ring size or the basicity of the ligand. It is therefore suggested that in this case other factors such as unfavourable preequilibria must be considered as important.     

Synthesis of benzimidazole derivatives. 11. Imidatricarbocyanines with substituents in the polymethine chain

In order to investigate their optical properties, imidatricarbocyanines of the benzimidazole series containing methyl, methoxy, and cyano groups as substituents in the polymethine chain have been synthesized.For communication 10, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 524–527, April, 1980.