bluuebunny/crossref_metadata_2025 huggingface dataset:
SYNTHÈSES D'ACIDES AMINOBUTYRIQUES: II. ACIDES ALKYLAMINO-2 HYDROXY-4 BUTYRIQUES
Authors: Laliberté Réal , Berlinguet Louis
Published: May 2006

Starting from 2-bromo-4-butyrolactone which was treated with primary amines, five new 2-alkylamino-4-hydroxy-N-alkylbutyramides were obtained in good yields. Acid hydrolysis gave the corresponding lactones, which, when treated with Ba(OH)2, gave the 2-alkylamino-4-hydroxybutyric acids. The new derivatives of homoserine thus prepared are: 2-methylamino-4-hydroxybutyric acid, 2-ethylamino-4-hydroxybutyric acid, 2-propylamino-4-hydroxybutyric acid, 2-butylamino-4-hydroxybutyric acid, and 2-cyclohexylamino-4-hydroxybutyric acid.Some of these amides were easily lactonized in HCl-acetone medium. Two 2-alkylamino-4-chloro-N-alkylbutyramides were also prepared.
THE MASS SPECTRA OF THREE DEUTERATED BROMOBUTANES
Authors: McFadden W. H. , Lounsbury M.
Published: May 2006

The mass spectra of 1,1-dideutero-1-bromobutane, 1,1,1,3,3-pentadeutero-2-bromobutane, and 1,1,1,2,3,3-hexadeutero-2-bromobutane have been obtained using 70-volt ionizing electrons. The cracking patterns of the deuterated molecules are compared with those of the undeuterated bromobutanes. It is shown that no hydrogen–deuterium exchange occurs in certain ions formed from the parent ion by simple bond break but that extensive exchange of hydrogen and deuterium occurs in ions formed by further decomposition of unsaturated daughter ions.Formation of HBr+ or loss of HBr to form C4H8+ from 2-bromobutane is shown to favor sterically the hydrogen on carbon 4 and not to involve that on carbon 2. However, in the case of 1-bromobutane, formation of these ions does not appear to involve any particular hydrogen preferentially, because if one assumes that all hydrogens in the molecule are involved, then the hydrogen on carbon 1 appears to be involved to an almost statistical extent.In two cases the isotopic substitution so modifies the rate of a metastable reaction that the metastable peak disappears from the spectra of the deuterated species.
CARBON-13 KINETIC ISOTOPE EFFECTS IN BIMOLECULAR REACTIONS
Authors: Stothers J. B. , Bourns A. N.
Published: May 2006

Carbon-13 kinetic isotope effects have been measured for the bimolecular reaction of 1-phenyl-1-bromoethane (I) and benzyl bromide (II) with alkoxide ion in alcohol solution. Compound I gave an effect, k12/k13, of 1.0032 ± 0.0005 for reaction with ethoxide ion in ethanol, while II gave k12/k13 = 1.0531 ± 0.0004 for reaction with methoxide ion in methanol. These surprisingly different effects are tentatively interpreted in terms of a model for the transition state having varying degrees of ionic character.
GAS–LIQUID PARTITION CHROMATOGRAPHY OF SESQUITERPENE COMPOUNDS
Authors: Nigam Ishwar C. , levi leo
Published: May 2006

Sesquiterpene compounds were effectively separated by gas chromatography and identified by infrared spectrophotometry. Examples given include the recovery and characterization of β-caryophyllene and β-humulene from oil of balsam copaiba, of α- and β-vetivone from oil of vetiver, and of α- and β-santalol from oil of sandalwood.
KINETIC STUDY OF THE ISOMERIZATION OF n-BUTENES ON CHROMIA–ALUMINA
Authors: Amenomiya Y. , Cvetanović R. J.
Published: May 2006

Mutual interconversions of the three n-butenes on a chromia–alumina catalyst have been studied in a temperature range between 210 and 260 °C and in a pressure range from about 10 to about 100 mm. Dependence of initial rates on the initial pressures of the reactants was determined experimentally. The initial rates of isomerization could be, in each case, expressed empirically by a rate equation conforming to the Langmuir–Hinshelwood formula. It was possible to explain the experimental results by assuming the existence of three different adsorbed species for the three n-butene isomers and their surface interconversions as the rate-determining step.
STEROIDS AND RELATED PRODUCTS: XIX. THE SYNTHESIS OF 3,9,12,20-TETRAOXYGENATED 9,12-seco STEROIDS. PART III. 11-AZA STEROIDS. PART I
Authors: Engel Ch. R. , Rakhit S.
Published: May 2006

The smooth conversion of 3β-acetoxy-5α-pregnane-12,20-dione (IV), readily available from hecogenin (I), to Δ9(11)-3β,20β-diacetoxy-5α-pregnan-12-one (VIII) is reported. Ozonolysis of this product in ethyl acetate gave, in almost 90% yield, 3β-hydroxy-20β-acetoxy-9-oxo-9,12-seco-11-nor-5α-pregnan-12-oic acid (XI), further characterized by its ester derivatives XIa and XIb. The conversion of the seco acid XI to Δ8(9)-3β-hydroxy-20β-acetoxy-9-amino-9,12-seco-11-nor-5α-pregnen-12-oic acid lactam (12 → 9) (XII) and thence to Δ8(9)-N-acetyl-3β,20β-diacetoxy-11-aza-5α-pregnene (XIVa), the first 11-aza steroids to be known, is described. On the other hand, Δ9(11)-3β,20β-diacetoxy-5α-pregnen-12-one (VIII) is readily transformed to the 9α,11α-glycol VII with osmium tetroxide and thence, with periodic acid, to 3β,9α-dihydroxy-20β-acetoxy-11-oxo-11,12-seco-5α-pregnan-12-oic acid (X), characterized as the methyl ester Xa and diacetoxy methyl ester Xb, and easily converted to the acetoxy hydroxy keto dicarboxylic seco acid XIII. In the course of this work it is shown that, whereas ketalization of the saturated 12,20-diketone IV with ethylene glycol and boron trifluoride etherate gives a good yield of the 12-monoketal (in accordance with the reports of the literature), treatment of the analogous 16-unsaturated 12,20-diketone with the same reagents under the same conditions leads not to ketal formation but to addition of ethylene glycol in position 16.
THE CHEMISTRY OF ALUMINUM–NITROGEN COMPOUNDS: III. THE STRUCTURE AND PYROLYSIS OF Me3Al:Me2NN=NNMe2
Authors: Fetter Neil R. , Brinckman Jr. Frederick E. , Moore Donald W.
Published: May 2006

not available
STRUCTURE OF THE EXTRACELLULAR POLYSACCHARIDE PRODUCED BY XANTHOMONAS ORYZAE
Authors: Misaki A. , Kirkwood S. , Scaletti J. V. , Smith F.
Published: May 2006

The extracellular polysaccharide isolated from cultures of Xanthomonas oryzae is composed of D-glucose (5 molecular proportions), D-glucuronic acid (2 molecular proportions), and D-mannose (5 molecular proportions). Acid hydrolysis of this polysaccharide, which contains 0.3% combined pyruvic acid, yields 2-O-β-D-glucopyranosyluronic acid D-mannose, which has been characterized as its crystalline fully methylated β-glycoside. Hydrolysis of the methylated polysaccharide gives 2,3,4,6-tetra-O-methyl-D-mannose (3 molecular proportions), 2,3,4-tri-O-methyl-D-glucuronic acid (1 molecular proportion), 2,3,6-tri-O-methyl-D-glucose (4 molecular proportions), 3,4,6-tri-O-methyl-D-mannose (2 molecular proportions), 2,6-di-O-methyl-D-glucose (3 molecular proportions), 2,3-di-O-methyl-D-glucose (1 molecular proportion). The polyalcohol derived from the polysaccharide by periodate oxidation followed by sodium borohydride reduction gives upon acid hydrolysis glycerol (2 molecular proportions), erythritol (1 molecular proportion), and D-glucose (1 molecular proportion). The general structural significance of these findings is discussed.
COORDINATION COMPLEXES OF METAL ALKOXIDES: PART II. METAL ALKOXIDE – ETHYLENEDIAMINE COMPLEXES
Authors: Bains M. S. , Bradley D. C.
Published: May 2006

Some complexes of titanium isopropoxide, titanium ethoxide, aluminum isopropoxide, tantalum isopropoxide, and zirconium isopropoxide with ethylenediamine (en) are described. Two complexes of titanium isopropoxide with ethylenediamine, i.e. Ti(OPri)4,en and Ti2(OPri)8,en, were established by cryoscopic, X-ray powder photograph, and phase rule studies. The structure and stability of these complexes is discussed. Also isolated were Ti2(OEt)8,en; Zr2(OPri)8,en; Ta2(OPri)10,en, and Al2(OPri)6,en. Cryoscopic studies on the aluminum complex suggested that an octameric complex, Al8(OPri)24, (en)4, is present in equilibrium with the dimer. The structural implications of the existence of these complexes are discussed.Phase studies on the binary systems containing titanium tetraisopropoxide and pyridine, diethylamine, or tert-butyl acetate gave no clear indication of complex formation.
HYDROLYSIS PRODUCTS OF PERIODATE-OXIDIZED PHOSPHOMANNAN Y-2448
Authors: Jeanes Allene , Pittsley J. E. , Watson P. R. , Sloneker J. H.
Published: May 2006

Sequences of at least three α-1,3-linked mannose units have been shown to occur in phosphomannan Y-2448 through isolation of 3-O-[3-O-(α-D-mannopyranosyl)-α-D-mannopyranosyl]-D-mannose from partial acid hydrolyzates of both the native and the periodateoxidized phosphomannan. 3-O-(α-D-Mannopyranosyl)-D-mannose has been obtained also. The mannosidic bond in these oligosaccharides appears to be more stable to acid hydrolysis than that by which the mannose 6-phosphate unit is held in this macromolecular polysaccharide derivative. It has been established that the D-mannose 6-phosphate unit is oxidized by periodate and that orthophosphate is the form which occurs in this phosphomannan.
SPECTROSCOPIC STUDIES OF KETO–ENOL EQUILIBRIA: PART 1. SOLVENT EFFECTS
Authors: Murthy A. S. N. , Balasubramanian A. , Rao C. N. R. , Kasturi T. R.
Published: May 2006

Solvent effects on the keto–enol equilibria of ethyl acetoacetate, acetylacetone, ethyl cyclopentanone-2-carboxylate, and methyl 4-methylcyclopentane-1-,2-dione-3,4,5-tricarboxylate have been studied by ultraviolet spectroscopy. The extent of enolization is mainly determined by the stabilization of the keto form by local association with polar or proton-donating solvent molecules, just as in the case of n → π* transitions and infrared stretching frequencies. Solvent effects on infrared spectra reveal useful information regarding the characteristic frequencies of the tautomers.
THE CRYSTALLINE FORM OF 1,3,5,7-TETRANITRO-1,3,5,7-TETRAZACYCLOOCTANE (HMX)
Authors: Bedard M. , Huber H. , Myers J. L. , Wright George F
Published: May 2006

The absorption spectra and dielectric constants of three of the four polymorphs of 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) have been examined. The difference in absorption frequencies shows that these crystal forms are more distinctive than are most polymorphs. Likewise the distortion polarizations of HMX-I, -II, and -III are markedly different whereas identical distortion polarizations have been found among typical polymorphic systems. The distortion polarizations of HMX-II and -III also are unique because they are appreciably temperature dependent, although this electrical property ought to be temperature independent. Because of these unique behaviors we have postulated that the so-called HMX polymorphs actually are lattice-caged conformational modifications.
THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF METHANE
Authors: Back R. A. , Auwera D. van der
Published: May 2006

The mercury-photosensitized decomposition of methane has been studied at temperatures ranging from about 25 to 400 °C, and pressures from about 100 to 1000 mm. Very low conversions and light intensities were employed, and it was shown that at temperatures of 120 °C and above, the hydrogen produced was a direct measure of the primary yield of hydrogen atoms. The low, temperature-dependent quantum yield found in earlier studies persisted even under these conditions, and it seems necessary to postulate an inefficiency in the primary quenching process, involving essentially the quenching of 3P1 mercury atoms by methane without decomposition of the methane.Experiments with added ethylene showed that practically all the hydrogen produced in the decomposition of methane was scavengeable by ethylene, indicating that only atomic hydrogen was produced in the primary process. The rate of addition of hydrogen atoms to ethylene was estimated to be about 4 × 105 times faster than the rate of abstraction from methane at 120 °C.
A CONTINUOUS FLOW BETA SCINTILLATION DETECTOR FOR AQUEOUS SOLUTIONS
Authors: Tkachuk R.
Published: May 2006

Counting of beta emitters in aqueous solutions was carried out with a detector whose detecting element is a packed column of a finely divided plastic scintillator. The efficiencies under practical operating conditions for C14, Sr90–Y90, and K40 are 36, 74, and 82% at backgrounds of 27 ± 2 c.p.m.
THE INFRARED SPECTRA OF N-ACYLTRIALKYLAMMONIUM HALIDES, IN RELATION TO THOSE OF AMIDE SALTS
Authors: Cook Denys
Published: May 2006

N-Acyltrialkylammonium halides have been prepared from the trialkylamine and acid halides. The ionic solids so produced can be easily handled in inert atmospheres but are easily attacked by moisture. Their infrared spectra have strong carbonyl bands near 1800 cm−1, showing that the R3N+ group, when attached to an acyl group, has strong electron-with-drawing characteristics, to a rather greater extent than the halogens in acid halides.Structurally, the N-acyltrialkylammonium halides would be similar to protonated (or alkylated) amides, if such protonation (or alkylation) occurred at the nitrogen atom. Since all amide salts examined hitherto have carbonyl frequencies over 100 cm−1 lower than 1800 cm−1 it is concluded that this work offers further evidence that protonation in amides occurs at the oxygen atom.
THE PREPARATION OF SUCROSE MONOESTERS
Authors: Lemieux R. U. , McInnes A. G.
Published: May 2006

The Snell procedure for the preparation of sucrose monoesters of the higher saturated fatty acids by transesterification of sucrose and methyl esters in N,N-dimethylformamide was found to yield variable results due to the use of solid potassium carbonate as catalyst and to impurities in the solvent. A kinetic study of the reaction revealed that yields of sucrose ester and rates of reaction were reproducible when conditions for homogeneous catalysis were established. The reaction followed first-order kinetics in methyl ester and sucrate ion and the rate of reaction was essentially independent of the sucrose concentration, the molecular weight of the fatty acid, and the nature of the metal sucrate used to catalyze the reaction. The activation energy for the reaction was 9.9 kcal mole−1. Equilibrium constants for the principal reactions were determined, and it was established that only the thermodynamic product prevailed at any time throughout the transesterification reaction. A preparative method for the synthesis of sucrose monoesters was developed that gave yields of sucrose ester, based on the amount of methyl ester which had reacted, which were essentially quantitative. The product contained about 20% of di-and 80% of mono-ester.
STEREOCHEMISTRY OF ARSENIC: PART VI. TRI-p-TOLYLARSINE
Authors: Trotter J.
Published: May 2006

Crystals of tri-p-tolylarsine are rhombohedral, with cell dimensions a = 9.84 Å, α = 80° 2′, and space group [Formula: see text]. There are two molecules in the unit cell, and hence the molecule has symmetry C3. The structure has been determined from a projection along the rhombohedral cell axis, and the bond lengths and valency angles are given. In comparison with an ideal model having maximum interaction between the arsenic lone pair and the aromatic π-electrons, each ring is rotated about its As—C bond by 36°, the three rotations being in the same sense. These displacements increase overcrowded distances in the ideal model to about the normal van der Waals separations, the closest intramolecular contacts between p-tolyl groups being [Formula: see text] and [Formula: see text]. All the intermolecular contacts correspond to van der Waals interactions.
HYDROGEN CHEMISORPTION ON NICKEL–MAGNESIA CATALYSTS
Authors: Ramasubramanian N. , Yeddanapalli L. M.
Published: May 2006

The hydrogen adsorption activities, per gram of nickel, of two nickel–magnesia catalysts are compared and explained on the basis of different types of nickel being present. The application of the Elovich equation to interpret the kinetic data shows the possibility of the presence of three kinetic stages in the temperature and pressure range studied. A study of the effect, on the hydrogen adsorption, of deliberate oxygen addition to and re-reduction of the catalyst surface shows that the nature of the oxygen contamination in the catalyst is different from that of the added oxygen.
OXIDATION STATES OF MANGANESE IN FUSED ALKALI NITRATES
Authors: Bennett Ruth M. , Holmes Owen G.
Published: May 2006

When dissolved in fused alkali nitrate, manganese (II) is oxidized to MnO2. In the same solvent MnO4− decomposes to MnO2. Peroxide ion arrests the decomposition at MnO42−, while the presence of hydroxide ion results in the formation of MnO43−. The spectra of MnO42− and MnO43− in molten nitrate show great similarity to their spectra in alkaline aqueous solution.
METALLO-ORGANIC COMPOUNDS CONTAINING METAL–NITROGEN BONDS: PART IV. SOME BIS-(PRIMARY AMINO)-TITANIUM COMPOUNDS
Authors: Bradley D. C. , Torrible E. G.
Published: May 2006

The aminolysis reactions involving primary amines with either Ti(NMe2)4 or Ti(NEt2)4 have been studied. The primary amines behave as bifunctional reactants, forming colored, insoluble, non-volatile bis-(primary amino)-titanium compounds Ti(NR)2 which (except for R = C6H5) are highly reactive towards water or alcohols. With n-butylamine, some soluble polymers of the general formula Tix(NBun)2x−2(NEt2)4 were isolated. With tert-butyl-amine the dimers Ti2(NBut)2(NMe2)4 and Ti2(NBut)2(NHBut)2(NMe2)2 were obtained. The structures of these polymeric metal–nitrogen compounds are discussed.
STÉROÏDES: CCXIX PREPARATION ET PROPRIÉTÉS DE QUELQUES 17-ISO-PREGNANES ET 17-ISO-PREGNÈNES SUBSTITUÉS EN C-16
Authors: Crabbé Pierre , Pérez Magdalena , Vera Gloria
Published: May 2006

The preparation of 16β-carboxy-(5α)-17α-pregnane-3β-ol-20-one and 16β-carbomethoxy-3β-fluoro-17α-Δ5-pregnene-20-one, as well as several of their derivatives, is described. The stereochemistry of these compounds is deduced from their optical rotatory dispersion curves.
STRUCTURE OF PYROLYZED POLYVINYLIDENE CHLORIDE
Authors: Dacey J. R. , Barradas R. G.
Published: May 2006

Systematic infrared analyses, using the standard KBr pellet technique, of samples ranging from the pure polymer (Saran) to the fully carbonized charcoal have been examined in an attempt to clarify the structural changes and mechanism of decomposition of the polymer on pyrolysis. A complementary technique has been investigated for obtaining homogeneous samples of the carbon and of the partially pyrolyzed polymer which will transmit infrared radiation without the use of any halide dispersal medium. The significance, possible applications, and limitations of these spectral studies are discussed. Pore volumes have been examined by means of a modified helium displacement densitometer and also through the adsorption of argon in a McBain–Bakr balance. Porosity measurements based on the adsorption of argon at its saturation vapor pressure are more satisfactory and they contribute towards a better understanding of the microstructure of Saran charcoal and of its partially carbonized antecedents. The influence of pelletizing pressure has been found to play an important role in the determination of pore volumes.
POLAROGRAPHIC REDUCTION OF ORTHO ALKYL NITROBENZENES
Authors: Wheeler Owen H.
Published: May 2006

not available
2,3-DIPHENYLBUTANE-2,3-DIOL. SOLVENT EFFECTS
Authors: Agahigian H. , Moraveck J. F. , Gauthier H.
Published: May 2006

not available
N-β-D-GLUCOPYRANOSYLTHIOUREA
Authors: Benn M. H.
Published: May 2006

not available
THE PREPARATION OF ALKALI DITHIONATES
Authors: Larson D. W. , O'Donnell R. W. , VanCleave A. B. , Eager R. L.
Published: May 2006

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THE SYSTEM LITHIUM SULPHATE – ZINC SULPHATE – WATER AT 30 °C
Authors: Aravamudan G.
Published: May 2006

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CONFORMATIONAL EQUILIBRIUM IN ESTERS OF CYCOHEXANOL BY PROTON MAGNETIC RESONANCE: V. ADJACENT DEUTERATION
Authors: Allan E. A. , Premuzic E. , Reeves L. W.
Published: May 2006

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THE EFFECT OF AGITATION ON THE RATE OF NATTA TYPE PROPYLENE POLYMERIZATION
Authors: Keii T. , Taira M. , Takagi T.
Published: May 2006

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DEGRADATION OF D-RIBONO-1 → 4-LACTONE TO D-ERYTHRONO-1 → 4-LACTONE
Authors: Mitchell D. L.
Published: May 2006

not available
OXYGEN-18 TRACER EVIDENCE FOR THE TERMINATION MECHANISM IN THE PHOTOCHEMICAL OXIDATION OF ACETALDEHYDE
Authors: McDowell C. A. , Sifniades S.
Published: May 2006

The chain-terminating step in the photochemical oxidation of acetaldehyde in the gas phase has earlier been established to be the reaction[Formula: see text]Using oxygen-18 of 99.4% purity in the form of molecular oxygen we have made a careful study of the variation of the isotopic ratios of the various oxygens, by mass spectrometry, during the course of the photooxidation. The results show conclusively that the mechanism of the termination step is:[Formula: see text]where O* represents O18. Thus the recombination terminating reaction takes place with the elimination of one oxygen atom from each reacting peroxy AcOO radical. The mechanism of this elimination process is thought to be as follows:[Formula: see text]
A NEW TECHNIQUE FOR THE STUDY OF HIGH-POLYMER DEGRADATION REACTIONS
Authors: Jellinek H. H. G. , Clark J. E.
Published: May 2006

A quartz spoon gauge, recording pressures automatically, is described. The gauge, representing a closed reaction system, can be used for investigations of the degradation of polymers. It has been tested by degrading polymethylmethacrylate over a temperature range of 300 to 400 °C. The important features of the gauge are as follows: (1) The pressure exerted by gases during degradation is continuously recorded at appropriate chart speeds via an electrical transducer (maximum displacement ± 0.038 cm; spoon gauges used in this work had sensitivities in the region of 0.035 cm/atm). (2) Only small quantities of polymers are needed; 20 to 40 mg of polymer in the form of films was deposited on the walls of the reaction vessels; however, much smaller samples could be used, the limit being given by mechanical vibrations set up in the system. (3) Temperature equilibrium between the reaction vessels and a thermostated bath is reached within about 30 seconds.Useful results for polymethylmethacrylate were obtained up to 400 °C, which is a temperature about 100° higher than that reached by previous workers, not neglecting the initial parts of the reactions. The reproducibility of the results has been indicated by average curves obtained from several runs at any one particular temperature and their standard deviations.
INTRAMOLECULAR HYDROGEN BONDING AND THE ANHARMONICITY OF THE NH2STRETCHING VIBRATIONS IN SUBSTITUTED ANILINES
Authors: Krueger P. J.
Published: May 2006

The fundamental and first overtone NH2stretching bands in 55 ortho-, meta-, and para-substituted anilines, measured in dilute carbon tetrachloride solution, have been compared. For all ortho-substituted compounds (except o-alkyl, o-COCH3, and o-COOCH2CH3) splitting of the symmetric band is observed in the first overtone region. On the basis of unusually low mechanical anharmonicity the high-frequency component is assigned to a vibration arising in an intramolecularly bonded NH2group. The mechanical anharmonicity of the "free" NH2group is found to be more dependent on the electronic nature of meta and para substituents for the symmetric mode than for the asymmetric mode, with minor changes on ortho substitution. The relative electrical anharmonicities for both modes have been estimated from changes in the ratio of the integrated intensity of the fundamental band to that of the first overtone band. For the asymmetric mode the electrical anharmonicity is independent of the electronic nature of the substituents, but depends on their ring position. For the symmetric mode the electrical anharmonicity decreases as charge separation increases in the molecule, with no significant difference for ortho-substituted compounds. These results are in qualitative agreement with a mechanism previously proposed for these vibrations.
THE O-INSIDE CONFORMATION OF 1,3:2,4-DI-O-METHYLENE-L-THREITOL
Authors: Lemieux R. U. , Howard J.
Published: May 2006

1,3:2,4-Di-O-methylene-L-threitol was shown by measurement of its dipole moment and nuclear magnetic resonance spectrum to exist in the so-called O-inside conformation as would have been predicted by Mills.
VAPOR–LIQUID EQUILIBRIA, DENSITIES, AND REFRACTIVITIES IN THE SYSTEM ACETIC ACID – CHLOROFORM – WATER AT 25 °C
Authors: Campbell A. N. , Kartzmark E. M. , Gieskes J. M. T. M.
Published: May 2006

The volume changes on mixing of the two binary mixtures acetic acid – water and acetic acid – chloroform and of the ternary mixture acetic acid – chloroform – water have been determined. In the system acetic acid – water a volume contraction occurs, showing a minimum excess molar volume at 50 mole%. Partial molal volume determinations suggest the formation of a mixed association of one molecule of water with one molecule of acetic acid. In the system acetic acid – chloroform the excess molar volume function is positive over the complete concentration range and this suggests the probability of a positive deviation from Raoult's law.The refractivities of the two binary systems show that the true molecular volumes of acetic acid, water, and chloroform are additive on mixing.Studies of the vapor–liquid equilibria show that in all three constituent binary systems there is positive deviation from Raoult's law but if the dimerization of acetic acid in the vapor phase is taken into account the vapor pressure behavior of the system acetic acid – chloroform is virtually ideal. The vapor pressures in the ternary system show strong positive deviations from Raoult's law over the complete concentration range. This shows that the line of pseudo-ideality in terms of zero excess molar volume does not really represent ideal behavior. Zero excess molar volume is caused by the counteracting effects of water and of chloroform molecules on acetic acid molecules.In the two binary systems investigated the experimental data satisfy the Gibbs–Duhem–Margules equation. This proves that treatment for dimerization of acetic acid in the vapor phase is not merely permissible but necessary.
THE ALKALOIDS OF DELPHINIUM BROWNII RYDB: THE STRUCTURE OF BROWNIINE
Authors: Benn M. H. , Cameron M. A. M. , Edwards O. E.
Published: May 2006

Methyllycaconitine and browniine have been observed to be major alkaloids of Delphinium brownii. The latter was proved to have the same skeleton, oxygen location, and stereochemistry as lycoctonine, but a different pattern of O-methylation.
OXIDATION–REDUCTION POLYMERS: II. STANDARD OXIDATION POTENTIALS OF REDOX HOMOPOLYMERS AND THEIR MONOMERIC MODELS
Authors: Spinner I. H. , Raper W. D. , Metanomski W.
Published: May 2006

A new monomer, 2,5-bis-(2-tetrahydropyranyloxy)-4-methyl-4′-vinyldiphenyl sulphone, has been prepared. The standard oxidation potentials of two linear redox homopolymers, derived from this monomer and the one previously reported (1), and of their intermediate and model compounds, have been measured using continuous and discontinuous titration techniques.
WALLACH REARRANGEMENT OF UNSYMMETRICALLY SUBSTITUTED AZOXYBENZENES AND OXIDATION OF AZO DERIVATIVES
Authors: Singh Joginder , Singh Pritam , Boivin J. L. , Gagnon Paul E.
Published: May 2006

The Wallach rearrangement of 3-chloro-3′-methyl- and 3-methyl-3′-nitro-azoxybenzene gave rise to the corresponding 4′-hydroxyazo derivatives with the hydroxyl group attached to the benzene ring adjacent to the trivalent nitrogen bridge, while 2,2′,5,5′-tetrachloro-4′-nitro- and 2′-nitro-4,4′,5,5′-tetrachloro-azoxybenzene were hydroxylated in the ortho and para positions respectively on the ring adjacent to the pentavalent nitrogen bridge.Oxidation of 3-methyl-3′-nitro-and 3-chloro-3′-methyl-azobenzene gave rise to the corresponding α-isomers, which was proved by the bromination and reduction products.The ultraviolet and visible absorption spectra of the unsymmetrically and symmetrically substituted azo- and azoxy-benzenes prepared have been recorded and briefly discussed.
PHASE EQUILIBRIUM STUDIES FOR THE TERNARY SYSTEM URANYL NITRATE – NITRIC ACID – WATER
Authors: Gaunt J. , Bastien I. J. , Adelman M.
Published: May 2006

Phase equilibrium studies were carried out on the system UO2(NO3)2−HNO3−H2O between the temperatures of −10 °C and +49.1 °C over a wide concentration range of both UO2(NO3)2 and HNO3. No phase separation occurred above 49.1 °C for the concentrations studied. The three hydrates of UO2(NO3)2 were identified in the solid phase, and a new complex of UO2(NO3)2, possibly UO2(NO3)2.3HNO3, was separated as the solid phase at higher nitric acid concentrations.
INCREASE IN THE ANODIC OVERPOTENTIAL OF ELECTROPOLISHED ALUMINUM ON EXPOSURE TO DRY AIR AT 25 °C—A FILM THICKNESS OR SPECIFIC IONIC CONDUCTANCE EFFECT
Authors: Dignam M.J.
Published: May 2006

not available
PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS XII. RACEMIZATION OF sec-BUTANOL
Authors: Withey R. J. , Whalley E.
Published: May 2006

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GAS CHROMATOGRAPHIC SEPARATION OF HYDROGEN ISOTOPES ON ACTIVATED ALUMINA
Authors: Venugopalan M. , Kutschke K. O.
Published: May 2006

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SYNTHESIS OF ALKYLETHYNYL COMPOUNDS OF MERCURY
Authors: Kraut M. , Leitch L. C.
Published: May 2006

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THE PREPARATION OF 2,3-DICYANO-5,6-DICHLOROQUINONE (D.D.Q.)
Authors: Mitchell P. W. D.
Published: May 2006

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METHANOLYSIS OF CARBOHYDRATE ORTHOACETATES
Authors: Perlin A. S.
Published: May 2006

Acid methanolysis of D-mannose 1,2-(methyl orthoacetate) 3,4,6-triacetate (I) yields mainly 3,4,6-tri-O-acetyl-D-mannose (II). D-glucose 1,2-(ethyl orthoacetate) 3,4,6-triacetate (VIII) yields 3,4,6-tri-O-acetyl-D-glucose and methyl 3,4,6-tri-O-acetyl-β-D-glucopyranoside. The rate of methanolysis of II differs little from that of VIII, in marked contrast to the relative rates of hydrolysis of these compounds in aqueous acid. Several concurrent reactions appear to take place in methanol initiated by protonation at different positions on the orthoester ring.During isolation, II is converted partially to 2,4,6-tri-O-acetyl-D-mannose (VI), a novel instance of acyl migration in the sugar series. Structural assignments for these two triacetates are based on chemical and proton magnetic resonance spectral data. The 2-acetate group of VI migrates during methylation, both II and VI yielding the same 2-O-methyl ether.
THE ELECTRON DENSITY DISTRIBUTIONS IN HYDRIDE MOLECULES: I. THE WATER MOLECULE
Authors: Bader R. F. W. , Jones G. A.
Published: May 2006

The electron density distribution for the water molecule in its equilibrium configuration is determined by requiring that the forces exerted on the nuclei by this distribution (as calculated by the Hellmann–Feynman theorem) balance the nuclear forces of repulsion. The density distribution is expressed in terms of equivalent orbitals, and to achieve electrostatic equilibrium it is found necessary to have an angle between the bonding orbitals which is less than the structural bond angle (bent bonds), to delocalize the equivalent orbitals and to place the lone pair electrons in sp hybrid orbitals. Further, a discussion of the forces operative in XH2 and XH3 molecules (X = C, N, O) leads to an explanation of the observed bond angles and to general conclusions regarding the hybridization to be expected in such molecules.
REARRANGEMENT STUDIES WITH C14: XIV. THE REACTION OF 2-p-ANISYLETHANOL-1-C14 WITH THIONYL CHLORIDE
Authors: Lee C. C. , Newman Donna , Thornhill D. P.
Published: May 2006

Reaction between 2-p-anisylethanol-1-C14 and thionyl chloride was carried out with pyridine, n-hexane, toluene, dioxane, or excess thionyl chloride as solvent. The 2-p-anisylethyl chloride obtained showed rearrangement of the C14 label from the C-1 to C-2 positions ranging from about 0.5% for the reaction in pyridine to about 46% for the reaction in excess thionyl chloride. The results can be explained on the basis of varying degrees of involvement of the ethylene-p-methoxyphenonium chlorosulphite ion pair, thus supporting the suggestion that thermal decomposition of alkyl chlorosulphites to give chlorides may be considerably ionic in character.
THE STRUCTURE OF '3-HYDROXYPYRROLES'
Authors: Atkinson R. S. , Bullock E.
Published: May 2006

Spectroscopic studies by infrared, ultraviolet, and n.m.r. methods have shown that '3-hydroxypyrroles' exist in the 4-oxo-Δ2-pyrroline form and are not tautomeric substances.
METAL OXIDE TRIALKYLSILYLOXIDE POLYMERS (POLYTRIALKYLSILOXANOMETALLOXANES): PART I. TITANIUM OXIDE TRIMETHYLSILYLOXIDE POLYMERS
Authors: Bradley D. C. , Prevedorou-Demas C.
Published: May 2006

Tetrakis-(trimethylsilyloxy)-titanium Ti(OSiMe3)4 has been hydrolyzed under controlled conditions in dioxane. The initial products of hydrolysis undergo facile disproportionation, e.g. 3Ti2O(OSiMe3)6 → 4Ti(OSiMe3)4 + polymeric Ti2O3(OSiMe3)2. Molecular weight determinations were made on the titanium oxide trimethylsilyloxide polymers (polytrimethylsiloxanotitanoxanes) obtained by thermal disproportionation. Structures have been suggested for the polymers on the basis of the variation of number-average degree of polymerization with the degree of hydrolysis.
STUDIES ON THE PIGMENTS OF PENICILLIUM HERQUEI
Authors: Narasimhachari N. , Vining L. C.
Published: May 2006

Several minor pigments from cultures of Penicillium herquei are described. One of these has been identified as the naphthalic anhydride which is formed when atrovenetin is oxidized with alkaline peroxide. Evidence is presented which suggests that the characteristic green pigment found in this fungus is formed by a reaction analogous to that between ninhydrin and amino derivatives. In P. herquei the 1,2,3-trione is probably generated by mild oxidation of perinaphthenone pigments known to be produced by this organism.
STERIC EFFECTS IN THE SYNERGIC EXTRACTION OF THE LANTHANIDES, YTTRIUM, AND SCANDIUM
Authors: Manning P. G.
Published: May 2006

From a study of the partitioning of the carrier-free radioisotopes Tm170, Ce144, Eu152/154, Tb160, Lu177, and Y91 between nitric acid and organic solutions containing various proportions of thenoyltrifluoroacetone (HTTA) and dialkyl alkyl phosphonates (S) in odorless kerosene, concentration equilibrium constants (k2) have been computed for the reaction[Formula: see text]where M represents a metal ion, and "w" and "o" are aqueous and organic species respectively.When used in conjunction with the data of Bronaugh and Suttle, the equilibrium constants determined in this study yielded comparative equilibrium constants (k3) for the solvation process [Formula: see text]for the rare-earth metals listed.In the extraction of Sc46, however, the species extracted is dependent on the alkyl groups of the phosphonates, the butyl and 2-ethylhexyl derivatives giving mono- and di-solvates respectively.It is concluded that steric effects are dominant in these synergic systems.
THE COLORIMETRIC DETERMINATION OF PLATINUM WITH 5-(p-DIMETHYLAMINOBENZYLIDENE)-RHODANINE
Authors: Piercy Frances E. , Ryan D. E.
Published: May 2006

5-(p-Dimethylaminobenzylidene)-rhodanine is used to determine 0.5 to 6 p.p.m. of platinum colorimetrically, after reduction of platinum IV with ascorbic acid. Platinum can be determined in the presence of a 10-fold excess of palladium; low concentrations of the other platinum metals, except rhodium, do not seriously interfere.
KINETICS OF THE REACTION H +C3H8 = H2 + C3H7
Authors: Kazmi H. A. , Diefendorf R. J. , Roy D. J. Le
Published: May 2006

The kinetics of the reaction H + C3H8 = H2 + C3H7 have been studied in the range 95 to 170 °C by a method permitting the evaluation of the absolute value of the rate constant. This was found to be 2.2×10−10exp (−8.2×103/RT) cm3 molecule−1sec−1.
SYNTHESIS IN THE PYRIDINE SERIES: III. THE SYNTHESIS OF NEW 3,5-DIMETHYL-4-SUBSTITUTED PYRIDINES. STERIC EFFECTS AS AN AID TO SYNTHESIS
Authors: Kutney James P. , Tabata T.
Published: May 2006

A synthetic sequence leading to 3,5-dimethyl-4-substituted pyridines is described. The sequence takes advantage of the steric influence exerted by substituents attached to the pyridine nucleus at the 3- and 5-positions on functional groups at the 4-position. In this manner a number of new trialkylated pyridines become available.
NUCLEAR MAGNETIC RESONANCE SPECTRA OF DURENE AND MESITYLENE DERIVATIVES
Authors: Bullock E.
Published: May 2006

The nuclear methyl groups and ring protons in nitro- and dimethylamino-durenes and -mesitylenes show considerable chemical shifts relative to the parent hydrocarbons. The shifts are generally in the direction expected from a mesomeric effect, despite the lack of coplanarity between the aromatic ring and the substituent.
THE SYSTEM ALUMINUM–ANTIMONY–BISMUTH
Authors: Campbell A. N. , Winkler J.
Published: May 2006

A complete study, by the methods of thermal and isothermal analysis and of X-ray powder photography, has been made of the equilibrium diagram of the system aluminum–antimony–bismuth. The critical solution temperature and composition of the congruent liquids in the system aluminum–bismuth have been determined as have also the compositions of congruent liquids in the ternary system. The only compound occurring in this system is AlSb and the solid model is largely occupied by the equilibrium surface of this compound.An explanation of the anomalous form of the solidus in the antimony–bismuth system is given.
THE REACTION OF ISOPROPANOL VAPOR WITH Hg 6(3P1) ATOMS: PART II: REACTION IN THE PRESENCE OF NITRIC OXIDE
Authors: Knight Arthur R. , Gunning Harry E.
Published: May 2006

The reaction of isopropanol vapor with Hg 6(3P1) atoms in the presence of nitric oxide has been investigated in a static system at room temperature as a function of exposure time. In addition to the major products hydrogen, pinacol, and acetone found in the pure substrate reaction, the new products isopropyl nitrite, nitrous oxide, and nitrogen were observed. The effect on the reaction of the inert gas carbon tetrafluoride was also studied.Evidence is adduced for the production of excited isopropoxy radicals in the primary process, and the rise in the nitrite and acetone yields, observed upon increasing the added inert gas pressure, is ascribed to quenching of these excited species.The nitrite produced in the decomposition of Me2CDOH was found to be ca. 98% Me2CDONO, dictating its formation from the isopropoxy radical and not from Me2COH.A nitrite-producing dark reaction was observed when high pressures of CF4 were added and the reaction could be prevented only by measures designed to exclude trace quantities of NO2 from the reaction vessel.
THE SYNTHESIS OF CYCLIC ANALOGUES OF TOLBUTAMIDE
Authors: Simmons D. L. , Dodsworth J. M. , Chubb Francis L.
Published: May 2006

not available
THE PREPARATION OF DEHYDROABIETANE-1-AMINE
Authors: Stockel Richard F.
Published: May 2006

The preparation of dehydroabietane-1-amine (II) has been achieved and characterized by base hydrolysis of the methyl carbamate (VII) via the following path: acid (I) → acid chloride (IV) → amide (V) → methyl carbamate (VII) → primary amine (II). The overall yield from acid (I) to amine (II) was approximately 50%. Other reactions leading to poor yields of the primary amine are discussed.
ELECTRICAL POLARIZATION OF TETRAMETHYLCYCLOBUTANES
Authors: Lautenschlaeger F. , Wright George F
Published: May 2006

Because the postulated non-planarity of sym-tetramethylcyclobutanedione is based on a small value of electrical polarization, the cis- and trans-2,2,4,4-tetramethylcyclobutane-1,3-diisocyanides have been prepared and stereospecifically rearranged to the analogous dicyanides. These substances show sufficiently large polarizations that the explanation of ring non-planarity is substantiated. Calculations in terms of the expected and observed dipole moments show that the ring deviates 20–30° from planarity. Although this non-planarity is not static, according to consideration of the cis geoisomers it would appear that one conformation is more prevalent than any others.
THE STUDY OF VIBRATIONALLY EXCITED N2 MOLECULES WITH THE AID OF AN ISOTHERMAL CALORIMETER
Authors: Morgan J. E. , Schiff H. I.
Published: May 2006

Vibrationally excited nitrogen molecules produced both by a microwave discharge in nitrogen and also by the reaction[Formula: see text]have been examined using an isothermal calorimetric probe.In the first case the energy associated with an 'active' nitrogen stream, due to vibrationally excited N2, was found to be 6.03 kcal mole−1 of total nitrogen. The subsequent relaxation of this species was found to occur almost entirely on the walls of the reaction vessel, with a collision efficiency of 4.5 × 10−4. The addition of other gases greatly accelerated the homogeneous relaxation rate. Collisional efficiencies of N2O, CO2, and Ar were found to be 0.8 × l0−4, 2.3 × 10−5, and 1.0 × 10−6 respectively.The vibrationally excited nitrogen produced by the N/NO reaction was found to possess 20 ± 4 kcal mole−1 of energy compared with the maximum of 75 kcal mole−1 allowed by the exothermicity of the reaction.
5-ARYL- AND 5-ALKYL-1,2,3,4-THIATRIAZOLES: SYNTHETIC, SPECTROSCOPIC, AND DEGRADATIVE STUDIES
Authors: Lieber Eugene , Rao C. N. R. , Orlowski R. C.
Published: May 2006

A number of 5-(p-substituted)phenyl-1,2,3,4-thiatriazoles have been synthesized by the diazotization of p-substituted thiobenzhydrazides or by the reaction of sodium thiobenzoyl-thioglycollates with sodium azide. The thermal decomposition of these thiatriazoles yields nitriles, nitrogen, and sulphur. 5-Alkyl-1,2,3,4-thiatriazoles are very unstable and readily decompose to nitriles. Infrared and ultraviolet absorption spectra of 5-(p-substituted)phenyl-1,2,3,4-thiatriazoles have been studied. Infrared spectra of several thiohydrazides have also been studied and there appears to be no thiol–thione tautomerism in these derivatives. The thiatriazole ring is found to be electron withdrawing.
THE REACTION OF POLYISOPRENE WITH TITANIUM TETRACHLORIDE
Authors: Golub Morton A. , Heller Jorge
Published: May 2006

The reaction of titanium tetrachloride with hevea, balata, and synthetic cis-polyisoprene in benzene at 80 °C has been studied. The most prominent change in the infrared spectra of these polymers is the nearly total disappearance of the 12 μ band after prolonged reaction with TiCl4. The diminution of this band, associated with the loss of the original —C(CH3)=CH— units, whether cis or trans, followed pseudo-first-order kinetics, the rate varying with [TiCl4]n, where n is 1.0 in the case of the cis polymers and 1.5 in the case of the trans polymer. Contrary to previous reports, practically no cis–trans isomerization of polyisoprene occurs in the course of this reaction, the data being explained entirely by cyclization. With the help of cis-1,4 polymers of isoprene-3-d and 2-methyl-d3-1,3-butadiene-1,1-d2, it was concluded that cyclization, involving a TiCl4-induced carbonium ion mechanism, leads to the formation of six-membered rings fused into predominantly bicyclic structures, connected by methylene groups and/or uncyclized monomer units. Each of the fused ring structures contains a single tetra-, tri-, or di-substituted double bond, the relative amounts of which are in the order tetra- > tri- > di-substituted.
THE APPARENT IONIZATION CONSTANTS OF SOME ORGANOSILYLMETHYLBENZOIC ACIDS
Authors: Allcock H. R.
Published: May 2006

The apparent ionization constants of several organosilylmethylbenzoic acids of formula p-R3SiCH2C6H4CO2H were measured in 39 wt% aqueous methanol using a spectrophotometric method. p-(CH3)3SiCH2C6H4CO2H was found to be a slightly stronger acid than p-(C2H5)3SiCH2C6H4CO2H and p-(n-C3H7)3SiCH2C6H4CO2H, but replacement of (CH3)3Si in p-(CH3)3SiCH2C6H4CO2H by (C6H5)(CH3)2Si—, (p-CH3C6H4)(CH3)2Si—, and (C6H5)3Si—brought about no significant change in acid strength. All the organosilylmethlybenzoic acids studied were weaker acids than p-toluic acid.
DIFFUSION WITH MIGRATION IN THE DIFFUSE DOUBLE LAYER
Authors: Rangarajan S. K.
Published: May 2006

The polarization characteristics of the concentration of the reactive species are discussed when the effects of migration in the diffuse layer are accounted for. A limiting case (ξ0 → ∞) and some particular cases (|Zi/Z| = 0, 1, 2, 3, 4) are derived both for attraction and repulsion in the double layer. Linear approximations (and conditions sufficient to validate these) are presented. Some general results which relate the functional forms of the transforms of the interfacial concentrations for the cases of attraction and repulsion are also pointed out.
FARADAIC IMPEDANCE: EFFECT OF MIGRATION IN THE DIFFUSE DOUBLE LAYER
Authors: Rangarajan S. K.
Published: May 2006

The expressions for the elements of the equivalent circuit are derived by making use of the modified solutions for the diffusion equation (with migration in the diffuse layer) obtained earlier. The impedance (faradaic) characteristics are discussed. Also, the results are compared with those of Matsuda and Delahay.
ORGANIC PEROXIDES: VI. REACTION OF PHENOLS AND SECONDARY AROMATIC AMINES WITH p-NITROBENZOYL AND p,p′-DINITROBENZOYL PEROXIDES
Authors: Edward J. T. , Samad S. A.
Published: May 2006

not available
ALUMINUM ALKOXIDE INDUCED REARRANGEMENT DURING THE OPPENAUER OXIDATION OF CYCLOPROPYLCARBINOL
Authors: Lee C. C. , Bhardwaj I. S.
Published: May 2006

not available
AN EXPLOSION WITH METHYL AZIDE
Authors: Currie C. L. , Darwent B. deB.
Published: May 2006

not available
THE PROTONATION OF THE CARBONYL GROUP: III. DIARYL KETONES
Authors: Stewart Ross , Granger M. R. , Moodie R. B. , Muenster L. J.
Published: May 2006

The basicities of 14 diaryl ketones have been determined. Except for 4,4′-bis(dimethyl-amino)benzophenone, which protonates on nitrogen, the pKBH+ values range from −4.19 for 4,4′-dihydroxybenzophenone to −10.12 for 4,4′-dinitrobenzophenone. The basicities are not correlated well by either σ or σ+ substituent constants and it is believed that this is due either to a variation in the degree of rotation (and hence conjugation) of the two aryl rings or to a departure of carbonyl basicities from the conventional acidity scale based on ammonia bases. The effect on the basicity of joining the ortho positions by bridges of various sizes has also been determined and the results are discussed in terms of steric and electronic effects.
THE BAKER–NATHAN EFFECT OBSERVED IN THE RELATIVE RATES OF REDUCTION OF SEVERAL PARA-ALKYLATEDNITROBENZENES BY SODIUM HYDROSULPHIDE
Authors: Cope O. J. , Brown R. K.
Published: May 2006

By measuring the initial rates of production of hydrodisulphide during reductions by sodium hydrosulphide in aqueous ethanol, it has been shown that the relative rates of reduction of a number of para-alkylated nitrobenzenes are in the order p-H- > p-t-butyl- > p-isopropyl- = p-cyclohexyl- > p-ethyl- > p-methyl-nitrobenzene. This is in accord with the "hyperconjugative" order of electron release by these alkyl groups.
SUBSTITUTED PHENYLACETYLENES. INFRARED SPECTRA
Authors: Allen A. D. , Cook C. D.
Published: May 2006

A series of substituted phenylacetylenes has been prepared and their infrared spectra recorded. The C≡C and ≡C—H stretching frequencies are only slightly affected by substituents in the phenyl ring. Substituents in the 4-position cause a splitting of the ≡C—H band into two clearly resolved bands of similar intensity, about 10 cm−1apart.
CRITICAL PHENOMENA IN THE SYSTEM ACETIC ACID – CHLOROFORM – WATER
Authors: Campbell A. N. , Kartzmark E. M.
Published: May 2006

This paper is an experimental study of (a) the solid–liquid equilibria at low temperatures; (b) equilibrium compositions at temperatures other than 25 °C; (c) the critical phenomena, L1–L2, L1–V, and L2–V, in the acetic acid – chloroform – water system. No previous study has been made of critical phenomena in a system exhibiting partial liquid miscibility.