bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Complexes of 2‐acetylpyridine with Cu2+, Ni2+ and Co2+. Part II
Authors: Kirson B. 
Published: November 2013

AbstractThe enolization of 2‐acetylpyridine during the formation of the complex only takes place when the metal ion is not bonded to halogen. The halogen ions of CuII, NiII and CoII form Ketonic complexes with 2‐acetylpyridine. The cobalt in the complex of 2‐acetylpyridine remains divalent even in the presence of factors which usually cause oxidation. The Ketonic complexes of the above metals are not stable in aqueous solution, and in concentrated alcoholic solutions the Ketonic complex may be transformed to the enolic complex.
The Photocycloaddition of Olefins to Unsaturated 3‐Ketosteroids
Authors: Rubin M.B. , Maymon T. , Glover D. 
Published: November 2013

AbstractPhotoadditions of ethylene and of cyclopentene to Δ4 ‐ and Δ4,6‐3‐ketosteroids gave mixtures of cis‐4α,5α and trans‐4α. 5β adducts. In the case of cyclopentene and Δ4,6‐androstadiene‐3‐one‐17β‐ol propionate, only the trans adduct was observed. Cis‐4β,5β adducts were obtained by base‐catalyzed isomerization of the trans adducts. The ratio of cis:trans adducts varied considerably with solvent, temperature, and olefin concentration in steroid reactions but not in reactions with cyclohexenone. The different types of adducts exhibited markedly different ORD curves in agreement with the structures assigned. Carbonyl maxima of trans adducts appeared at shorter wavelengths than maxima of cis adducts in both infrared and ultraviolet spectra. The infrared shifts provide a convenient method for differentiating between cis and trans fused isomers.
The Preparation and Crystal Structure of TlMnCl3, TlFeCl3, TlCoCl3 and TlNiCl3
Authors: Zodkevitz A. , Makovsky J. , Kalman Z. H. 
Published: November 2013

AbstractThe compounds TlMnCl3, TlFeCl3, TlCoCl3 and TlNiCl3 were prepared by heating T1C1 with the corresponding transition metal dichloride in an evacuated ampoule. Atomic positions were determined from powder photographs. All four compounds were found to be related to the perovskite type structure. TlMnCl3 has a cubic structure, space group Pm3m, with ao = 5.025 Å. The other three compounds are hexagonal, probable space group P63mc, with cell dimensions (in Å) a0 = 6.976 and c0 = 6.008 for the Fe compound, a0 = 6.907 and c0 = 5.981 for the Co compound and a0 = 6.863 and c0 = 5.881 for the Ni compound. The three hexagonal compounds are isomorphous. A measureable concentration of basal plane stacking faults was found to occur in TlFeCl3 and also, to a lesser degree, in TlCoCl3.
Organic Fluorine Compounds. Part XLII. The Reaction of Amides of α‐Bromoacids with Potassium Fluoride
Authors: Shahak I. , Rozen S. , Bergmann E. D. 
Published: November 2013

AbstractThe reaction of potassium fluoride with α‐bromocarboxylic acid anilides, substituted in the α‐ or β‐position, causes dehydrohalogenation and gives α, β‐unsaturated anilides. Long‐chain α,α′‐dibromodicarboxylic acid (>C8) anilides give in the same reaction essentially α,αprime;‐di‐fluorocarboxylic acid anilides.
Inhibition of Catalase by Cyanide
Authors: Kremer M. L. 
Published: November 2013

AbstractThe kinetics of the inhibition of the catalatic reaction by cyanide is investigated. The inhibition is formally competitive. Cyanide can combine with both the free enzyme and the active enzyme substrate complex, the latter combination being more labile. The dissociation constant of the enzyme‐substrate‐inhibitor complex for horse liver catalase has been calculated from spectrophotometric data: Ki+ = 14 ± 4 μM. The agreement with the value calculated from kinetic data by Beers for horse blood catalase is satisfactory.
Adsorption and Oxidation of I− and I2 at Solid Electrodes as Functions of the Anode Potential
Authors: Gliksman‐Reis I. , Königsbuch M. 
Published: November 2013

AbstractThe mechanism of the electrochemical oxidation of I− and I2 at the bright Pt and Au electrodes and at platinized Pt ‐ electrodes saturated with H2 or O2, was investigated by voltammetric and adsorption measurements. I131 was used for adsorption detection. I− is strongly adsorbed and electrochemically oxidized to IO−at the bright electrodes as a function of the anode potential, but relatively weak adsorption takes place at the platinized electrodes. I2 shows an apparent desorption as a function of anode potential.
Octahedral Chloride Complexes of Trivalent Actinides and Lanthanides in Solution
Authors: Marcus Y. , Bomse M. 
Published: November 2013

AbstractThe preparation of the crystalline octahedral complex tris (triphenylphosphonium) hexachloro‐americate (III) is reported. The absorption spectra of the octahedral hexachloro complexes of curium (III), americium (III) and most of the trivalent lanthanides in a nitrile solvent are also reported. The dissociation of the hexachloro americate complex anion in the nitrile solvent and in propylene carbonate has been examined. The stepwise association constant K6 for its formation from the pentachloro complex was found to be 150 ± 20 and 60 ± 20 in 85% vol succinonitrile 15% acetonitrile solvent and in propylene carbonate respectively.
Organic Fluorine Compounds. Part 43. Applications of (1,1,2‐Trifluoro‐2‐Chloroethyl)‐Diethylamine as Fluorinating Agent
Authors: Bergmann E. D. , Cohen A. M. 
Published: November 2013

AbstractThe use of (1,1,2‐trifluoro‐2‐chloroethyl)‐diethylamine for the replacement of a hydroxyl group by a fluorine atom has been investigated. Particular attention has been paid to hydroxy‐compounds carrying other functional groups, e. g. carbonyl, ester and amino‐groups and combinations of them.
Sorption of Cyclohexylamine by Montmorillonites
Authors: Yariv S. , Heller L. 
Published: November 2013

AbstractInfrared spectra indicate that protonation of cyclohexylamine sorbed by montmorillonite depends upon the interlayer cations and the origin of the lattice charge. No protonation occurs with Cs and very little with Na, but with all the other interlayer cations studied cyclohexylammonium ions are formed. Protonation occurs more readily if the lattice charge originates in the octahedral layer. Various associations are inferred between interlayer hydroxides, hydrated cations, ionic and molecular cyclohexylamine and water. The sorption of cyclohexylamine is compared with that of aniline and the validity of the concept “surface acidity” is questioned.
Mössbauer Effect and Resistivity Studies in Fe1.11Te
Authors: Hermon E. , Nolan R. D. , Shtrikman S. 
Published: November 2013

AbstractMössbauer effect and electrical resistivity measurements were undertaken on Fe571.11Te. The Mössbauer studies show a magnetic ordering at 68°K, which is identified with the antiferromagnetic transition previously reported for this phase. Comparison of the room and liquid helium temperature spectra indicate that the antiferromagnetic axis lies in the tetragonal plane. The temperature coefficient of the resistivity changes sign near the transition temperature and has a maximum at the transition temperature.
Determination of Chloride Content in Compounds and in Solutions of High Bromide to Chloride Concentration Ratios
Authors: Israel Y. , Gonen L. 
Published: November 2013

AbstractA method is described for the determination of chloride in compounds and in solutions of high bromide to chloride molar ratios (up to 6300:1). Solutions were boiled briefly with nitric acid to oxidize the bulk concentration of bromide ion to bromine gas which was then flushed with air. Chloride ion was titrated potentiometrically with silver nitrate in 80% i‐propanol‐water medium using a silver‐silver bromide indicator electrode and a chloride‐free reference electrode. Details of the potentiometric techniques peculiar to these titrations are described. The method was successfully applied to the determination of the chloride content of commercially available bromide reagents.
Spiranic β‐Ketoesters and their Pyrazolinones
Authors: Breiman R. , Avramoff M. 
Published: November 2013

AbstractA number of spiranic β‐ketoesters have been prepared and transformed into the corresponding phenylpyrazolinones by condensation with phenylhydrazine. The structures of the β‐ketoesters and the pyrazolinones, derived from their UV, IR and NMR spectra, are discussed.
Base Induced Isomerization of γ, δ‐Epoxyketones
Authors: Gaoni Y. 
Published: November 2013

AbstractBase treatment of open‐chain γ, δ ‐ epoxyketones yields usually two cyclopropane derivatives, a trans‐1‐acy1‐2(α ‐ hydroxyalkyl) cyclopropane (II) and a 2‐hydroxy‐3‐oxabicyclo[3, 1, 0] hexane (III). The NMR spectra and some other physical properties of compounds II and III and of some of their transformation products are reported.
Inductive Effects on Molecular Ionization Potentials. III. Primary, Secondary and Tertiary Aliphatic Amines
Authors: Levitt Barbara W. , Levitt L. S. 
Published: November 2013

AbstractIt is demonstrated that the ionization potentials of primary, secondary, and tertiary aliphatic amines correlate very well with the inductive and polar substituent constants, the only seriously deviating value being that for ammonia, itself. The correlation equation is found to be EI = 9.62 + 13.8 ΣσI.
Adsorption of Iodine and Bromine by Polyethylene Sulfide Containing Cotton Fabric
Authors: Avny Y. , Gur‐Arieh Z. , Zilkha A. 
Published: November 2013

AbstractThe adsorption of iodine and bromine by polyethylene sulfide‐containing fabrics was investigated. It was found that the halogens could be adsorbed from aqueous solution as well as from a saturated halogen atmosphere. Adsorption was attributed to complexation by the sulfide bonds in the polymer. Adsorption from aqueous solution led to the formation of a complex with a molar ratio of halogen molecules (X2) to ethylene sulfide units of 1:1, while that from gaseous iodine a ratio of 2 was obtained. Complexation was accompanied by a little degradation of the polysulfide which was attributed to halogenation of the polyethylene sulfide. High adsorption of bromine led to complete degradation of the cotton fabric due to oxidation of the cellulose. The adsorption of polyethylene sulfide in the fabric was much higher than that of homopolyethylene sulfide itself under comparable conditions.
NMR Investigation of the Reaction of 1,1‐Diarylethylenes with Seleninyl Chloride and Diselenium Dichloride
Authors: Elmaleh D. , Patai S. , Rappoport Z. 
Published: November 2013

AbstractThe reaction of 1, 1‐diarylethylenes with seleninyl chloride (SeOCl2) and with diselenium dichloride (Se2Cl2) to yield benzoselenopheno [2,3‐b] benzoselenophens was investigated by NMR. Several reaction intermediates have been tentatively identified in the reaction of 1, 1‐diphenylethylene, but its para‐substituted derivatives yielded no additional mechanistic information. The reaction of 1, 1‐diphenylethylene with thionyl chloride was also studied by NMR. Both the SeOCl2 and the SOCl2 reactions occur through analogous primary addition compounds.
Peptidyl‐tRNA. XIII. The Chromatographic Behavior of Peptidyl‐tRNAvalE. Coli on BD‐Cellulose Column
Authors: Ziv E. , De Groot N. , Rappoport S. , Lapidot Y. 
Published: November 2013

AbstractThe behavior of different peptidyl‐tRNAval from E. coli on benzoylated DEAE cellulose column is described. It was found that the elution pattern of N‐acetyl‐val‐tRNA differs from that of val‐tRNA. Glyn‐val‐tRNA (n = 2,3) and lys‐gly‐val‐tRNA are eluted from the column differently from val‐tRNA. Blocking of the free amino group of the peptide attached to the tRNA causes a further shift of the elution pattern. Val‐gly‐val‐tRNA and phe‐gly‐val‐tRNA are strongly retarded on the column as compared with val‐tRNA, probably because of the hydrophobic interaction between the peptidyl residue and the BD‐cellulose. It is suggested that the differences in the chromatographic behavior of the different tRNA derivatives are due at least partially to differences in conformation.
Inhibitors of Ovine Brain Glutamine Synthetase
Authors: Lustig Nitza , Mor G. , Lichtenstein N. 
Published: November 2013

AbstractThe following carbobenzoxy (Cbz) derivatives of amino acids markedly inhibit ovine brain glutamine synthetase: Cbz‐DL‐phenylglycine, α‐N‐Cbz‐β‐N‐benzyl‐L‐asparagine, Cbz‐L‐phenylalanine, Cbz‐L‐tryptophan, N‐Cbz‐S‐benzyl‐L‐cysteine, and α‐ϵ‐di‐Cbz‐L‐lysine. In all cases tested, the inhibition was of a mixed type. Cbz‐derivatives of aliphatic amino acids inhibit the synthesizing reaction rather weakly. In the presence of methanol (22% v/v) or ethanol (22% v/v) the synthesizing reaction is not, or only slightly, inhibited by Cbz‐derivatives which, at the same molar concentration, are highly inhibitory in the absence of the organic solvents. When, after preincubation with methanol or ethanol, the alcohols are removed by dialysis, the original susceptibility of the enzyme to the inhibitors is restored. The inhibitors are also ineffective in the presence of dioxane (11% v/v). Cbz‐derivatives of amino acids with an additional aromatic group also strongly inhibit the γ‐glutamyl transfer activity of ovine brain preparations. There, too, the inhibition is highly diminished in the presence of organic solvents. Whereas methanol and ethanol lower both the apparent Km and the maximum velocity of the synthesizing reaction, the maximum velocity of the transfer reaction is considerably increased in the presence of these alcohols.
Platinum‐Graphite Biamperometric Indication for the Low Concentration Determination of Antimony, Arsenic and Tin
Authors: Prasad B. B. , Khandelwal G. D. 
Published: November 2013

AbstractThe application of a bi‐electrode system for the determination of Sb (III), As (III) and Sn (II) in dilute solutions is described. The electrode system consists of a platinum microelectrode and a wax‐impregnated graphite electrode. Iodine is used as oxidant. The determinations are quite accurate even in 10−3–10−4M concentration range.
Solvation of Substituted Phenoxide Ions in T‐Butyl Alcohol‐Water Mixtures, from Kinetic Studies of Proton Exchange
Authors: Grunwald E. , Fong D.‐W. , Ralph E.K. 
Published: November 2013

AbstractRate constants (k2W or k2A) for proton exchange between a phenol, its conjugate base, and a water or t‐butyl alcohol molecule have been measured in a t‐butyl alcohol‐water mixture by nuclear magnetic resonance. Since k2W and k2A are both high (k2W > 108 sec−1 M−1), the ratio k2W/k2A measures the selective solvation of the O−‐site (of the phenoxide ions) by water and t‐butyl alcohol. In 11.47 mole % t‐butyl alcohol — 88.53 mole % water, k2W/k2A is found to be 14 ± 3 when the ionic reactant is ortho‐bromophenoxide ion, and 32 ± 8 when it is meta‐nitrophenoxide ion. The results suggest that substituents have a marked effect on the selective solvation of the O−‐site.
Energy of Activation and Water Structure
Authors: Perlmutter‐Hayman Berta 
Published: November 2013

AbstractInstances of temperature‐dependent apparent energies of activation EA, observed for hydrolysis reactions, are briefly reviewed, as are recent calculations according to which the presence of a reactant in two forms which are in mobile equilibrium may lead to a temperature‐dependent EA. These calculations are extended to a consideration of the temperature‐dependence of the specific heat of activation, and to the possibility of more than two forms being in equilibrium. It is shown in some detail how the equilibrium between broken and intact hydrogen bonds in water may be responsible for observed effects.
Solvent Isotope Effects — Second Thoughts About an Old Problem
Authors: Halevi E.A. 
Published: November 2013

AbstractThe commonly held Gross‐Butler theory of isotope effects in mixed H2O‐D2O solvents is reexamined. Special attention is given to the conventional separation of the free energy changes responsible for the isotope effect into contributions from “transfer” and “exchange”. The internal inconsistency of the theory is pointed out and its empirical utility is questioned.
Sorption of Copper Species from Organic Solutions on Anion Exchangers. Part I: Sorption on the Bromide form of the Exchanger
Authors: Cohen R. 
Published: November 2013

AbstractThe sorption of copper species from copper bromide and copper nitrate dissolved in a series of organic solvents onto the bromide form of an anion exchanger (Dowex 1 × 10) was studied. The species sorbed were identified and the products of exchange determined. A mechanism for the sorption from these solutions was suggested.
DTA Traces of Ammonium Perchlorate. Influence of Preheating and Aging
Authors: Simchen A. E. 
Published: November 2013

AbstractWhile 4 distinct endothermal processes are known to accompany the thermal decomposition of Ammonium Perchlorate (AP), the DTA thermograms show one endotherm corresponding to the structure transition at 240°C, and two exotherms. The different characteristic points of the DTA thermograms change with the thermal history of the sample and even with aging at ambient temperature. Periods of preheating at 150° lower the initial temperature of self‐heating at a later heating from about 300° for freshly recrystallised AP to about 210° after preheating for 4 days at 150°C. Heating‐cooling cycles above 200° (lower limit) up to 320° (upper limit) show for the first 2‐3 cycles the influence of the known “limited decomposition” of AP. On cooling there is a temperature delay in the structure transition cubic → orthorhombic, up to a constant limit of about 15°, and an apparent comminution of grains.
Dissociation Energies of S2, SO, Te2, SeO and P2 Molecules
Authors: Rai B. , Singh J. , Rai D.K. 
Published: November 2013

AbstractThe ground state dissociation energies of S2, SO, Te2, SeO and P2 molecules have been estimated by fitting the Szöke and Baitz electronegativity potential energy curves to the experimental RKRV curves. The estimates of dissociation energies obtained have been compared with earlier calculations.
Determination of Spurrite, Associated with Calcite, by Means of Differential Thermal Analysis
Authors: Gross S. 
Published: November 2013

AbstractDifferential thermal curves of spurrite‐calcite rocks show two characteristic endothermic peaks at 725–850°C and at 845–990°C, both due to decarbonization. A method for determining the amounts of calcite and spurrite when both are present is proposed using DTA analysis in conjunction with the determination of CO2 in the bulk sample. The results of DTA are confirmed by TG and X‐ray diffraction studies.
2‐Hydroxy‐4‐Benzamidothiosemicarbazide as a Chelating Reagent. Part I‐Studies on its Cobalt(II) and Cobalt(III) Complexes
Authors: Swami M.P. , Rastogi D.K. , Jain P.C. , Srivastava A.K. 
Published: November 2013

AbstractThree distinct cobalt complexes of 2‐hydroxy‐4‐benzamidothiosemicarbazide, [Co(C8H9N4O2S) (H2O)3] Cl (I), [Co(C3H9N4O2S) (OH) (H2 O)2] (II) and Na [Co(C8H9N4 O2 S) (OH)3] H2 O (III) have been prepared at pH 3.0, 9.0 and 12.5, respectively. Magnetic measurements show subnormal values of the magnetic moment for high‐spin octahedral cobaltous complexes. A possible correlation has been sought in nephelauxetic ratio, calculated from electronic spectral data. The values of 10 Dq, L.F.S.E. and Racah's interelectronic repulsion parameters have also been evaluated. The complex (III) is diamagnetic in nature.
Inductive Effects on Molecular Ionization Potentials. V. Hydrogen Sulfide and Aliphatic Thioethers
Authors: Levitt L.S. , Levitt Barbara W. 
Published: November 2013

AbstractThe ionization energies of thioethers, R2S, have been correlated with the polar substituent constants and the inductive substituent constants. Good correlations are obtained which indicate that the effect of alkyl substituents on the S‐atom is primarily an inductive one.
Propellanes XVII. An Effect of Ring‐Strain on the Synthesis of C‐10 Propellanes
Authors: Tatarsky D. , Kaufman M. , Ginsburg D. 
Published: November 2013

AbstractTwo angularly disubstituted diiodides II and IX were treated with n‐butyl lithium. In the former case [4.4.2] propellane‐3,8‐diene III was obtained. Ozonolysis followed by double intramolecular Dieckmann condensation led to [3.3.2] propella‐3,7‐dione VI. In the latter case cyclization to form [4.2.2] propell‐3‐ene X did not occur. Rather 4,7‐dimethylenecyclooctene XI was obtained.
New ZnS Polytypes of the Family 28L
Authors: Sonnenblick Y. , Kiflawi I. 
Published: November 2013

AbstractSeven new ZnS polytypes of the family 28L are identified. They are 28L (18 3 5 2), 84R (5 5 5 3 3 3 2 2)3, 28L (26 2), 28L (13 5 7 3), 84R (13 7 3 5)3, 28L (3 3 3 3 3 3 3 3 2 2), and 84R (7 3 3 3 3 3 3 3)3. Indications of polytype transformation are presented and discussed.
Crystalline Di‐Tert‐Butyl Trioxide and Dicumyl Trioxide
Authors: Bartlett Paul D. , Lahav Meir 
Published: November 2013

AbstractDi‐tert‐butyl trioxide has been prepared at −50° by photolysis of solid di‐tert‐butyl diperoxymonocarbonate and, more conveniently, by the reaction of ozone in Freon 12 (CF2Cl2) or methyl chloride with either dissolved tert‐butyl hydroperoxide or suspended hydrated sodium tert‐butyl peroxide. A low‐temperature procedure for freeing the product from accompanying tert‐butyl alcohol and other impurities is described. The ozone ‐ sodium salt method has also been applied to the preparation of crystalline dicumyl trioxide. These trioxides have the properties previously observed in solution. They are unstable at temperatures above −30°. NMR spectra of the trioxides are reported and compared with those of related compounds. Approximate rate constants for the thermal decomposition of dicumyl trioxide are reported.
Push‐Pull Electronic Activation of Reactions
Authors: Robinson R. 
Published: November 2013

AbstractElectron delocation, simple or conjugated, is postulated in many reaction mechanisms which are assumed to proceed by way of an activated phase. One‐way processes involving electron displacement are acceptable for additions, but dubious for substitutions. In the text below the bromination of anisole is mentioned. If it is assumed that the Br atom combines with C p‐ to OMe as the result of a full electron displacement, then it becomes necessary to reverse such displacements to remove H from the p‐position. The present hypothesis is that instead of two major translocations the same result could be achieved by a kind of oscillating displacement of smaller amplitude, alternating in opposite directions. In this case, the aromatic structure is never disturbed to any serious extent and side‐reactions are accordingly minimal. The theory is further exemplified by the reactions of acetals and similar types, including the ring‐forms of the sugars. Mention is also made of the probability that reactions of carbonium ions can be interpreted in terms of partial valencies.
Templates and Twinning in Topotaxy
Authors: Zanos Gougoutas J. 
Published: November 2013

AbstractThe oriented growth of a product phase within a reactant crystal (topotaxy) may be directionally unique if directional point‐group symmetry elements of the reactant crystal structure are preserved in the aligned crystal structure of the product. When the specific topotaxy results in an angular divergence between these elements, multiple orientations of the product phase may grow within the pseudomorph (conservative twinning). Irrespective of the specific topotaxy, the total product phase appears to orient so as to conserve the point‐group symmetry elements of the initial lattice. Several examples of conservative twinning in transformations of 2‐iododibenzoyl peroxides and the closely related benziodoxole structures are presented together with matrices describing the specific topotaxies. In most cases, several oriented products are simultaneously and consecutively formed and it is difficult a posteriori to define their individual roles in the transformation. Conservative twinning and sometimes its conspicuous absence provide important clues for the identification of that lattice which controls the alignment of a particular product phase.