bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES ON THE THERMODYNAMICS AND CONDUCTANCES OF MOLTEN SALTS AND THEIR MIXTURES: PART II. THE VISCOSITIES, HEATS OF FUSION, AND HEAT CAPACITIES OF LITHIUM CHLORATE AND LITHIUM CHLORATE–LITHIUM NITRATE MIXTURES
Authors: Campbell A. N. , Nagarajan M. K.
Published: May 2006

The viscosities at different temperatures of pure molten lithium chlorate and of mixtures of lithium chlorate with lithium nitrate have been determined with high precision. The heats of fusion, and the molar heat capacities of both solid and liquid lithium chlorate, and of mixtures of lithium chlorate and lithium nitrate have also been determined. The heat of the transition [Formula: see text] has been obtained as the difference between the heats of solution in water of the two forms. The enthalpy, free energy, and entropy of mixing have been derived.
STRONGLY BASIC SYSTEMS: IV. SUBSTITUENT EFFECTS ON THE ACIDITY OF AROMATIC AMINES
Authors: Stewart Ross , O'Donnell J. P.
Published: May 2006

The effect of ring substituents on the acidity of anilines and diphenylamines is examined. In general the effects are similar to those found in the analogous ionization of phenols. The acidities of diphenylamines having two or three nitro groups in one ring and variable substituents in the other ring can be correlated by the Hammett relation.A good correlation is found between the acidities and basicities of aromatic amines, although basicity is more sensitive to the presence of ring substituents than is acidity. The relation of these results to the general question of first and second dissociation constants of dibasic acids is considered.
THE ELECTROLYSIS OF ω-BROMOCARBOXYLIC ACIDS: II. PREPARATION OF LONG-CHAIN ω-BROMOCARBOXYLIC ESTERS BY MIXED COUPLING REACTIONS
Authors: Woolford R. G. , Arbic W. , Rosser Ann
Published: May 2006

An attempt to synthesize long-chain ω-bromocarboxylic esters from the mixed electrolyses of ω-bromocarboxylic acids and half-esters is described. Methyl 15-bromopentadecanoate was successfully prepared in this way in 37% yield, but other reactions producing methyl 16-bromohexadecanoate (by two different routes) and methyl 14-bromotetradecanoate gave low yields (6–18%) and difficulties in purification of products. The product analysis of these electrolyses (symmetrical and unsymmetrical coupling products, methyl esters of starting materials) is given. It is concluded that this method is more likely to be of specific rather than general use.
THE REACTION OF UNSATURATED CARBOHYDRATES WITH CARBON MONOXIDE AND HYDROGEN: II. STRUCTURE AND STEREOCHEMISTRY OF THE ANHYDRODEOXYHEXITOLS FROM 3,4-DI-O-ACETYL-D-XYLAL
Authors: Rosenthal Alex , Abson Derek
Published: May 2006

3,4-Di-O-acetyl-D-xylal reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield 1,5-anhydro-4-deoxy-D-arabino-hexitol (I) and 1,5-anhydro-4-deoxy-L-xylo-hexitol (II). The stereochemistry at C-5 of the hexitols was elucidated by correlation with the triol ether (VI) obtained by sodium borohydride reduction of the periodate oxidation product of 1,4-anhydro-5-deoxy-D-arabino-hexitol (VII). Reaction of 3,4-di-O-acetyl-D-xylal with carbon monoxide and deuterium afforded 1,5-anhydro-4-deoxy-D-arabino-hexitol-4,6,6-H32 (VIII) and 1,5-anhydro-4-deoxy-L-xylo-hexitol-4,6,6-H32 (IX). Examination of the nuclear magnetic resonance (n.m.r.) spectra of the normal and deuterated anhydrodeoxyhexitols confirmed the structural assignments and showed that cis-addition to the double bond takes place to give (IX).
THE TRANSMISSION OF THE POLAR EFFECTS OF SUBSTITUENTS IN AROMATIC AND ARYLALIPHATIC CARBOXYLIC ACIDS: REACTIONS OF THE ACIDS WITH DIAZODIPHENYLMETHANE IN ETHANOL
Authors: Bowden K. , Chapman N. B. , Shorter J.
Published: May 2006

Rate coefficients have been determined for the reactions in ethanol at 30° of diazodiphenylmethane with several groups of carboxylic acids. Each group included the parent acid and three nuclear substituted acids. The parent acids were: benzoic, phenylacetic, β-phenylpropionic, phenoxyacetic, and trans-cinnamic acid. The reactions of 3-fluoro- (or chloro-) or 4-methyl-biphenyl-4′-carboxylic, and of 9-X-10-anthroic acids (X = Me, Cl, or Br) were also studied similarly. The Hammett polar susceptibility constant, ρ, has been calculated for each set of reactions. The values of ρ are discussed in terms of transmission of electronic effects through the side-chain by a field effect, and for side-chains conjugated with the ring, by a π-electron effect, both of which are inversely proportional to the first power of the distance of the carbonyl group from the ring.
THE ELECTRON PARAMAGNETIC RESONANCE SPECTRA OF THE 2-CYANO-2-PROPYL RADICAL AND RELATED SPECIES
Authors: Pearson J. T. , Smith P. , Smith T. C.
Published: May 2006

not available
AMINO ACIDS AND PEPTIDES: II. SYNTHESIS OF ε-N-METHYL-L-LYSINE AND RELATED COMPOUNDS
Authors: Benoiton Leo
Published: May 2006

ε-N-Methyl-L-lysine, ε-N-ethyl-L-lysine, and δ-N-methyl-L-ornithine have been synthesized by alkylation of the α-N-benzoyl-ω-N-p-toluenesulphonylamino acid. ε-N-Methyl-L-lysine was also prepared by the formaldehyde – formic acid methylation of α-N-carbobenzoxy-ε-N-benzyl-L-lysine, obtained by borohydride treatment of α-N-carbobenzoxy-L-lysine in the presence of benzaldehyde. ε-N, ε-N-Dimethyl-L-lysine, ε-N-benzyl-L-lysine, and ε-N-methyl-L-lysine ethyl ester were also prepared.
LA DÉTERMINATION DU RAYON DE GIRATION DES MACROMOLÉCULES EN CHAÎNES DANS LES BONS SOLVANTS PAR DIFFUSION DE LA LUMIÈRE
Authors: Prud'homme Jacques , Sicotte Yvon
Published: May 2006

not available
THE ANALYSIS OF THE VOLATILE OILS OF THE LEAVES OF ARTEMISIA MEXICANA AND ARTEMISIA KLOTZCHIANA
Authors: Manjarrez A. , Medina F.
Published: May 2006

The analysis of neutral and phenolic fractions of the essential oils from A. mexicana and A. klotzchiana by means of gas–liquid chromatography was attempted. The mixtures of neutral fractions were resolved using preparative g.l.c., and identification of components was made by chemical, spectrophotometric, and n.m.r. methods. The phenolic components were identified by means of relative retention ratios and addition methods. From A. mexicana (−)α-phellandrene, (+) limonene, (−)β-phellandrene, (−) camphor, (−) borneol, thymol, carvacrol, and eugenol were identified. From A. klotzchiana (−) α-phellandrene, (+) limonene, 1,8-cineole, (+) β-thujone, (−) camphor, (−) borneol, carvacrol, and eugenol were isolated.
ISOLATION AND SOME STRUCTURAL FEATURES OF A POLYSACCHARIDE FROM BIRCH SAP
Authors: Urbas B. , Adams G. A. , Bishop C. T.
Published: May 2006

A polysaccharide, precipitated by cetyltrimethylammonium hydroxide from the non-dialyzable portion of birch xylem sap, contained D-galactose, D-mannose, and D-glucose in a molar ratio of 2:1.4:1 and small amounts of D-glucuronic acid. Periodate oxidation studies indicated that the polysaccharide was branched and contained a high proportion of periodate-resistant monosaccharides. This was confirmed by methylation and hydrolysis which yielded 2,3,4,6-tetra-O-methyl-D-glucose (2.0 moles); 2,4,6-tri-O-methyl-D-mannose (0.9 mole); 2,4,6-tri-O-methyl-D-galactose (3.8 moles); unidentified tri-O-methyl hexose (1.2 moles); and 3,5-di-O-methyl-D-mannose (1.8 moles). The latter, a new di-O-methyl-D-mannose, snowed the presence of D-mannofuranose units in the polysaccharide. This, together with the 1 → 3 linked α-D-mannopyranose units, makes this polysaccharide unique among plant products. Immunochemical tests with antipneumococcal and antiparatyphoid B horse sera confirmed the presence of D-glucuronic acid and D-glucopyranose non-reducing end groups and supported the other structural conclusions by showing that there were few, if any, 1 → 4 and 1 → 6 linked D-mannopyranose units or D-galactopyranose non-reducing end groups.
PHOTOLYSE DE L'IODURE DE VINYLE EN SOLUTION DANS LE TETRACHLORURE DE CARBONE
Authors: Roberge Pierre C. , Herman Jan A.
Published: May 2006

The photolysis of vinyl iodide in carbon tetrachloride solutions gives several products among which the most important are: acetylene, hydrogen iodide, iodine, ethylene, and vinyl chloride. A mechanism based on diffusion-controlled disproportionation of geminate radicals, as first proposed by Hamill, agrees well with the observed phenomena. To explain the diminishing production of ethylene and iodine with increasing concentration of the monomer, it is necessary to postulate a telomerization of the vinyl iodide.
COMMENTS ON N.M.R. SPECTRA OF THE XnAA′Xn′ TYPE
Authors: Harris R. K.
Published: May 2006

General expressions are derived for line positions and relative intensities in the X spectrum for an XnAA′Xn′ nuclear magnetic system in the case when Jx = 0. It is shown that in most cases it is possible to obtain the coupling constants involved by direct measurement of the spectrum using simple equations, but that this is not possible in certain limiting cases where the spectrum is deceptively simple.
NUCLEAR MAGNETIC RESONANCE STUDIES OF COMPOUNDS RELATED TO TETRAMETHYLDIPHOSPHINE DISULPHIDE
Authors: Harris R. K. , Hayter R. G.
Published: May 2006

The proton n.m.r. spectra of tetramethyldiphosphine disulphide and a number of related compounds have been obtained, yielding values for the nuclear magnetic parameters. Brief comments are made on these parameters. Double resonance experiments yielded the relative signs of the coupling constants for tetramethyldiphosphine sulphide and spectral analysis provided similar information for the disulphide. Comparisons are made with published data.
AN APPLICATION OF SOME ELECTRON DENSITY, ELECTRIC DIPOLE, AND MAGNETIC DIPOLE MODELS TO THE GAS PHASE PROTON SHIFTS OF SOME SUBSTITUTED ETHYLENES
Authors: Schaefer T. , Yonemoto T.
Published: May 2006

Measurements in the gas phase of the proton shifts relative to ethylene of methyl vinyl ether, of vinyl chloride, and of the three dichloroethylenes are reported. It is suggested that available molecular orbital calculations somewhat overestimate delocalization in the chloroethylenes. If this is so, then a model involving electrostatic fields arising from excess π-electron densities and from electric dipoles originating from the substituents, as well as magnetic fields from a point dipole representing the anisotropy of the substituents, predicts shifts in reasonable agreement with experiment for β-protons. The agreement for α-protons is not as good. The gas phase measurements are compared to measurements in the inert solvents, tetramethyl-silane or cyclohexane.
ON THE EFFECT OF AN ATTRACTIVE MORSE POTENTIAL ON THE VIBRATIONAL ENERGY TRANSFER
Authors: Shin H.
Published: May 2006

not available
RING CONTRACTION DURING THE LEAD TETRAACETATE OXIDATION OF REDUCING SUGARS
Authors: Perlin A. S.
Published: May 2006

The rate of oxidation of D-glucose by lead tetraacetate in acetic acid is affected little by a large change in concentration of reactants, showing that the glycol cleavage step is not rate-controlling. Oxidation of 3-O-methyl-6-O-trityl-D-glucose yields 3-O-formyl-2-O-methyl-5-O-trityl-D-arabinose; the latter is not derived by production initially of a 4-O-formyl derivative that undergoes acyl migration. It is probable that the oxidation of D-glucose proceeds with conversion of the pyranose sugar into a furanose intermediate. By contrast, D-mannose appears to be oxidized mainly in the pyranose form, as shown by the oxidation patterns of D-mannose-1- and -2-14C and 5-O-methyl-D-mannofuranose, and the effects of concentration change on the reaction of D-mannose and derivatives. The proximity of the ring oxygen atom to the 1,2-diol group may contribute to the unusually high reactivity of D-mannopyranose as compared with other types of monocyclic six-membered ring vic-diols.Intermediate proportions of furanose and pyranose pathways characterize the lead tetraacetate oxidation of the other six aldohexoses. Similarities in the behavior of glucose and idose, gulose and mannose, and allose and talose may originate in steric similarities between these pairs of sugars.
NEW NITROCHALCONES. VII
Authors: Szell T. , Eastham A. M. , Sipos Gy.
Published: May 2006

A number of new nitrohydroxychalcones have been synthesized using sodium hydroxide and hydrogen chloride as catalysts. It has been found that with substituents which increase the acidity of acetophenones or the electrophilic character of benzaldehydes (e.g. NO2, halogen, CN), sodium hydroxide is the better condensing agent, while with those substituents which increase the basic strength of the carbonyl, hydrogen chloride is satisfactory.
AMMONOLYSIS OF URONIC ESTER GROUPS IN BIRCH XYLAN
Authors: Wang Paul Y. , Bolker H. I. , Purves C. B.
Published: May 2006

Solvent-extracted white birch, kept near 20° in liquid ammonia under pressure for 72 h and then extracted with methanol to remove acetamide, retained 0.25% of amide nitrogen. Extraction of the very finely ground residual wood with hot water yielded 21% as a 4-O-methylglucuronoxylan containing 0.53% of amide nitrogen. Alkaline hydrolysis removed the amide absorption in the infrared and restored the normal xylan spectrum. These results, supported by various control experiments, showed that amide groups in the ammonia-treated wood were derived from lactone or ester groups in the original 4-O-methylglucuronoxylan. Some of the uronic acid groups in the native wood presumably existed as ester crosslinks.
RADIOLYSIS OF AQUEOUS BROMAL HYDRATE SOLUTIONS; DETECTION OF OXALIC AND GLYOXYLIC ACIDS
Authors: Eager R. L. , O'Donnell R. W. , Tusz L. J.
Published: May 2006

not available
A STUDY OF PROTON EXCHANGE REACTIONS OF SUBSTITUTED ANILINES IN TRIFLUOROACETIC ACID
Authors: Reynolds W. F. , Schaefer T.
Published: May 2006

The acid proton exchange rates of solutions of some halo-substituted anilines in trifluoroacetic acid have been determined by measuring the acid proton signal width. In addition, the proton exchange rate of protonated N,N-dimethylaniline in trifluoroacetic acid is discussed. It is suggested that proton exchange occurs via the following reaction:[Formula: see text]The reaction is believed to occur in two steps: the oppositely charged ions form ion pairs which then transfer protons internally. Experimental evidence indicates that the ion–pair dissociation constant is less than, or equal to, one.The activation energies range from 10 to 24 kcal/mole. The rate constants at 25 °C for a possible bi-ionic reaction are calculated. Ionic activity coefficients are estimated by the Debye–Hückel equation. Another set of rate constants is calculated, assuming that the ions exist partly or completely as ion pairs.The free energies, enthalpies, and entropies of activation are calculated for an ion-pair reaction and for an overall bi-ionic reaction. The free energies of activation range from 10 to 17 kcal/mole and for haloanilines are less than that of aniline. In the ortho- and para-substituted anilines, ΔF≠, in general, decreases with decreasing halogen electronegativity. ΔF≠ values for metasubstituted anilines decrease with increasing substituent electronegativity. ΔF≠ values are largest for parahaloanilines and smallest for orthohaloanilines. The ΔF≠ values for haloanilines can be rationalized by reasonable combinations of inductive and mesomeric effects. The values of entropies of activation are determined largely by the positions of the substituents. ΔS≠ values range from 35 to −10 entropy units (e.u.) with aniline and para-substituted anilines having the largest positive values and orthosubstituted anilines having negative values. The value of ΔF≠ for protonated N,N-dimethylaniline is larger than that for protonated aniline, as would be expected. ΔS≠ is quite small. This is attributed to steric hindrance of solvation of the dimethylanilinium ion.
THE STRUCTURE OF INDACONITINE
Authors: Gilman Robert E. , Marion Léo
Published: May 2006

The alkaloid indaconitine has been converted into delphinine by replacement of a secondary hydroxyl by hydrogen and substitution of an imino-methyl for the imino-ethyl group originally present. This correlation rigorously establishes the structure of indaconitine and its absolute configuration. The product of the saponification of indaconitine, pseudaconine, is identical with the product of the saponification of pseudaconitine, and this last alkaloid has been correlated previously with aconitine. It follows that the secondary hydroxyl which was removed in the conversion of indaconitine to delphinine has the same configuration as in aconitine.
ELECTROINITIATED POLYMERIZATION OF STYRENE: I. ELECTROLYSIS OF ALKALI METAL NITRATES IN DIMETHYLFORMAMIDE CONTAINING STYRENE MONOMER
Authors: Funt B. Lionel , Laurent Sharon Walker
Published: May 2006

Electrolysis of alkali metal salts in dimethylformamide containing styrene monomer produced polymerization. The rate of reaction increased with increase in current and monomer concentration and varied dramatically with choice of initiating salt. The alkali metal nitrates from sodium to cesium produced polymer but lithium was ineffective. KNO3 was the most efficient of the alkali metal salts tested.The effects of inhibitors on the rates of polymerization together with analysis of copolymer composition established that polymerization proceeded by an anionic mechanism.A detailed study with KNO3 solution showed that relatively high electrical efficiencies were attained and that the number-average molecular weights ranged between 2 000 and 5 000.
ELECTROINITIATED POLYMERIZATION OF STYRENE: II. KINETICS IN SOLUTIONS OF TETRAMETHYLAMMONIUM SALTS
Authors: Funt B. Lionel , Bhadani Suraj N.
Published: May 2006

The kinetics were studied of the electrically initiated polymerization of styrene in solutions of tetramethylammonium salts. The reaction was confined to the cathode and was found to proceed via an anionic mechanism. Free radical inhibitors had little influence on the yield of polymer, but the reaction was quenched by the addition of methanol.The polymerization was investigated at six currents between 10 and 100 mA and at eight initial concentrations of monomer. Kinetic analysis of the data indicated a dependence on the first power of monomer concentration and of current.The high electrical efficiencies and molecular weights of 15 000 to 50 000 contrast sharply with previous fruitless attempts to electroinitiate styrene polymerization. Some features of the mechanism are discussed.
THE INDUCED DECOMPOSITION OF tert-BUTYL HYDROPEROXIDE
Authors: Hiatt R. , Clipsham John , Visser Teunis
Published: May 2006

In a study of the "induced" decomposition of hydroperoxides by alkoxy radicals, tert-butyl hydroperoxide has been decomposed by the action of di-tert-butyl peroxyoxalate at 45°. The homolytic cleavage of peroxalate to tert-butoxy was unaffected by the presence of hydroperoxide and 7 to 10 molecules of hydroperoxide were destroyed for each radical thus produced. The kinetics have been analyzed and a mechanism developed which has significance for any system containing peroxy radicals.
LITHIUM CHLORIDE CATALYZED DECARBOXYLATION OF OXALACETIC ACID IN ETHANOL
Authors: Kosicki G. W. , Lipovac S. N. , Annett R. G.
Published: May 2006

The monovalent metal salt lithium chloride promotes the decarboxylation of oxalacetic acid in ethanol. The absorption peak which appears at 230 mμ during the reaction is interpreted to be the enol form of pyruvic acid. Hydrogen chloride has a similar effect on the decarboxylation.
PHOTOCHEMICAL SYNTHESES: 9. THE CONVERSION OF DIBENZOYLMETHANE TO TRIBENZOYLETHANE
Authors: Kornis G. , Mayo P. De
Published: May 2006

Irradiation of dibenzoylmethane in benzene gives tribenzoylethane. In more concentrated solution a solid dimer (II) separates which, on solution, is converted by dealdolization into an isomer. This isomer (I, R = H) on irradiation, gives tribenzoylethane in a photolytic reaction which has been shown to have some generality. The overall conversion of dibenzoylmethane to tribenzoylethane therefore involves two photochemical and one chemical reactions.
PHOTOCHEMICAL SYNTHESES: 10. ADDITION OF MALEIC ESTER TO CYCLOALKENES: THE PRODUCTS
Authors: Mayo P. De , Reid S. T. , Yip R. W.
Published: May 2006

The intermolecular photochemical cycloaddition of maleic ester to cyclopentene and to cyclohexene has been observed. The saturated products were diesters of the (3:2:0) and (4:2:0) bicycloheptane and octane series, respectively. The stereochemistry of these products was studied and, in the latter series, derivatives of the trans-fused (4:2:0) bicyclooctane system identified.In addition to the saturated esters, cyclohex-2-enyl succinic ester and cyclopent-2-enyl succinic ester, produced by addition of the cycloalkenyl radical to maleic ester, also were formed.
THE REACTION OF METHOXIDE ION WITH PERFLUOROCYCLOPENTENE
Authors: Stockel Richard F. , Beachem Michael T. , Megson Frederic H.
Published: May 2006

The reaction of methoxide ion with perfluorocyclopentene gave two major components. These have been identified as 1-fluoro-2-methoxyhexafluorocyclopentene (IIf) and 1,2-dimethoxyhexafluorocyclopentene (IIe).A third component (3-methoxy-2,4,4,5,5-pentafluoro-2-cyclopenten-1-one (VII)) was isolated and a structure is proposed based on n.m.r. evidence.A list of carbon–carbon double bond stretch frequencies is given for a number of 1,2-disubstituted perfluorocyclopentenes which follow the electronegativities of the atoms adjacent to the double bond.
A STUDY OF THE HYPOCHLORINATION OF STYRENE: PREPARATION OF CHLOROHYDRINS IN AQUEOUS ACETONE
Authors: Sumrell Gene , Wyman Bert M. , Howell Ronald G. , Harvey Mack C.
Published: May 2006

A study has been made of the hypochlorination of styrene and of the by-products which accompany the formation of styrene chlorohydrin. A process was developed utilizing hypochlorination in aqueous acetone which gave a yield of 72% of the chlorohydrin. Application of this procedure was extended to several other olefins with good results.
HYDROGEN SORPTION BY CADMIUM OXIDE
Authors: Low M. J. D. , Kamel A. M.
Published: May 2006

not available
SUBSTITUTED HYDANTOINS AND OROTIC ACIDS
Authors: Lemieux R. U. , Puskas I.
Published: May 2006

not available
PHOTOCHEMICAL TRANSFORMATIONS OF DIENES. III. THE PHOTOLYSIS OF 3- AND 3,6-SUBSTITUTED CHOLESTA-3,5-DIENES
Authors: Leznoff Clifford C. , Just George
Published: May 2006

not available
SYNTHÈSES DE LA TERT-BUTYL-4 DIMÉTHYL-2,2 CYCLOHEXANONE ET DE SES DÉRIVÉS
Authors: Richer Jean-Claude , Perrault Guy
Published: May 2006

not available
THE COPPER(II) SYN-PHENYL-2-PYRIDYL KETOXIME SYSTEM PART I
Authors: Meek T. L. , Cheney G. E.
Published: May 2006

A survey has been made of the reactions of both geometric isomers of phenyl-2-pyridyl ketoxime with metal ions. The complexes of copper(II) with the syn-phenyl isomer have been investigated. Acid dissociation constants of both geometric isomers, and of the 2:1 copper chelate of the syn-phenyl oxime have been determined.
THE MECHANISM OF THE DEHYDROBROMINATION OF TETRA-O-AGETYL-α-D-GLUGOPYRANOSYL BROMIDE
Authors: Lemieux R. U. , Lineback D. R.
Published: May 2006

The conversion of tetra-O-acetyl-α-D-glucopyranosyl bromide (I) to 2-acetoxy-D-glucal triacetate (II) was found to be catalyzed by secondary amines containing n-alkyl groups. Substitution at the α-positions of the amine reduced the catalysis. Although triethylamine and tri-n-propylamine did not serve as useful catalysts, the less hindered and strongly basic 1,4-diazabicyclo[2,2,2]octane was more effective than diethylamine. The reaction is strongly promoted by polar solvents and added salts—especially tetra-n-butylammonium bromide. The course of the reaction involves direct elimination of hydrogen bromide and this reaction is in competition with the formation of acetylated N-glucosides. A kinetic study of the reaction using a variety of amines led to the conclusion that the first stage of the reaction is dissociation of I to glycosyloxocarbonium ion strongly solvated by the amine. Depending on the structure of the amine, the second stage of the reaction may involve transfer of the 2-proton to the amine to form 11 at a faster or slower rate than the formation of the N to C1 bond of the acetylated N-glucoside. Conditions were established for the near quantitative conversion of I to II in about 1/100th the reaction time reported in the literature.
BIOSYNTHETIC INCORPORATION OF ONE-CARBON UNITS INTO BERBERINE AND HYDRASTINE
Authors: Gupta Ram Nath , Spenser Ian D.
Published: May 2006

The utilization of one-carbon precursors in the biosynthesis of hydrastine and berberine was investigated by tracer experiments with plants of Hydrastis canadensis L. The lactone group of hydrastine and the bridge carbon of berberine are shown to be derived from the S-methyl group of methionine.
EVIDENCE FOR ZnF2•2H2O DEHYDRATION AND X-RAY DIFFRACTION STUDIES
Authors: Secco E. A. , Martin Ronald R.
Published: May 2006

Evidence for a dihydrate of zinc fluoride ZnF2•2H2O from dehydration studies is reported. The structural changes accompanying the decomposition of the hydrate were followed by X-ray diffraction. The heating of the dihydrate in air was found to yield as residues (a) mixture of ZnF2 and its hemihydrate, (b) mixture of ZnF2 and ZnO, (c) the hemihydrate, and (d) ZnO.
SYNTHESIS OF SOME ALPHA-SUBSTITUTED CYSTINES
Authors: Thibert R. J. , Diederich J. F. G. , Rutherford K. G.
Published: May 2006

The synthesis of α-ethyl-, α-n-propyl-, α-n-butyl-, and α-phenyl-DL-cystine via hydantoin intermediates is reported.
ERRATUM: PRIMARY PROCESS STUDIES BY MONOISOTOPIC PHOTOSENSITIZATION ON THE REACTIONS OF Hg 6(3P1) ATOMS WITH ALKYL CHLORIDES
Authors: Wan J. K. S. , Strausz O. P. , Allen W. F. , Gunning H. E.
Published: May 2006

not available
THE LIFETIME OF THE STATE OF N2
Authors: Phillips L. F.
Published: May 2006

The decay of the blue emission from the active nitrogen – iodine flame has been measured at iodine pressures down to 1.4 × 10−4 torr. Extrapolation of the decay rate to zero iodine pressure yields a value of 0.89 ± 0.41 s−1 for the first-order rate constant in absence of iodine, corresponding to a mean lifetime of 1.1 s for the [Formula: see text] state of N2. The rate constants for the reactions[Formula: see text]and[Formula: see text]are (2.6 ± 0.3) × 10−11 exp (−68 ± 34/RT) and (8.3 ± 1.2) × 10−14 cm3 molecule−1 s−1 respectively.
REACTIONS OF AMIDES AND RELATED COMPOUNDS: I. N.M.R. (PROTON) INVESTIGATION OF N,N-DIMETHYLFORMAMIDE – LEWIS ACID ADDUCTS AND REMARKS ON THE RELATIVE STRENGTH OF LEWIS ACIDS
Authors: Kuhn Stephen J. , McIntyre John S.
Published: May 2006

The proton resonance spectra of a number of Lewis acid – N,N-dimethylformamide adducts in 2-nitropropane and methylene chloride solutions have been investigated and an attempt has been made to correlate the relative strength of Lewis acids with the chemical shift of the methyl protons. The order obtained for the relative strength of Lewis acids shows good agreement with the results obtained by other methods. The complex formation has taken place on the carbonyl oxygen of the N,N-dimethylformamide in all cases. The DMF – Lewis acid mole ratios were 1:1 in ZnCl2, AlCl3, PF5, BiCl3, InCl3, AsF5, SbCl5, SbF5, BF3, BCl3, BBr3. The 2:1 DMF – Lewis acid complexes of ZnCl2, SnCl4, SnBr4, Snl4, TiCl4, ZrBr4 have also been investigated.
CONSIDERATIONS OF ADSORBED IONIC INTERMEDIATES ON THE AgO/Ag2O ELECTRODE IN AQUEOUS ALKALINE SOLUTION
Authors: Barradas R. G. , Fraser G. H.
Published: May 2006

An experimental study of the kinetics for the electrochemical formation of AgO from Ag2O in aqueous alkaline solutions was reported in an earlier paper (1). The proposed mechanism for the rate-determining step was suggested to be the transfer of oxide ions across the mixed oxide interface. Further theoretical possibilities under Langmuir and Temkin conditions of surface coverages are considered here in the light of the previously obtained experimental data. In particular we examine the possibilities of the rate-determining step involving adsorbed ionic intermediates on the AgO/Ag2O electrode at the oxide/electrolyte interface. For the Temkin conditions, the intrinsic and induced heterogeneity models of Conway and his co-workers have been applied to our calculation of Tafel slopes. None of the mechanisms at the oxide/electrolyte interface were found to be rate-controlling.
ESSENTIAL OILS AND THEIR CONSTITUENTS: XXVII. COMPOSITION OF OIL OF GINGERGRASS
Authors: Nigam M. C. , Nigam Ishwar C. , Levi Leo
Published: May 2006

Oil of gingergrass was found to contain the following as yet unreported constituents: trans-p-menthene-8-diol-1,2; cis- and trans-carveol; cis- and trans-dihydrocarvone; piperitenone and limonene oxide. The presence of an aromatic compound for which gas chromatographic and infrared criteria of identity were determined was also demonstrated. Limonene oxide is probably the most important precursor of these and related monoterpenoids of the essential oil.
HYDROLYSIS OF A SERIES OF PRIMARY ALKYL CHLOROSULFATES: ENTROPY OF ACTIVATION AS A CRITERION OF FRAGMENTATION IN SOLVOLYTIC REACTIONS
Authors: Buncel E. , Millington J. P.
Published: May 2006

The solvolysis of the series of alkyl chlorosulfates, ROSO2Cl, where R = methyl, ethyl, n-propyl, isobutyl, and neopentyl, has been studied in 10 M aqueous dioxane. The relative reactivities fit well a solvolytic mechanism involving displacement by water on carbon, with OSO2Cl as the leaving group. The change in mechanism of solvolysis from bimolecular with the straight-chain chlorosulfates to unimolecular with neopentyl chlorosulfate is shown by the absence of the lyate ion effect and the observation of rearrangement in the latter case.The entropies of activation in chlorosulfate solvolysis appear to be abnormally large. It is proposed that the abnormal ΔS≠ indicates a transition state in which both carbon–oxygen and sulfur–chlorine bond weakening occurs. It is shown that some other solvolytic reactions that are characterized by abnormally high entropies of activation may be interpreted on the basis of multiple bond fission (fragmentation). The mechanism of SNi reactions is considered in this context.
REACTIONS OF THE ETHYL RADICAL: IV. ADDITION TO VINYL MONOMERS
Authors: James D. G. L. , MacCallum Duncan
Published: May 2006

The Arrhenius parameters have been measured for the addition of the ethyl radical to a representative selection of vinyl monomers in the gas phase. The wide range of reactivity observed was almost entirely due to the variation of the energy of activation, from 3.4 ± 0.4 kcal/mole for acrylonitrile to 6.9 ± 0.5 kcal/mole for vinyl acetate. No significant variation was found among the values of the pre-exponential factors, indicating uniformity of steric conditions at the site of radical attack. The rate constant for the addition of the ethyl radical is considered as an alternative to the copolymerization parameter Q0 as an index of the intrinsic reactivity of a monomer at a given temperature.
ENTHALPIES OF INTRAMOLECULAR HALOGEN–HYDROXYL INTERACTIONS
Authors: Baker A. W. , Shulgin A. T.
Published: May 2006

Enthalpies of halogen–hydroxyl interactions have been evaluated for the 2-halophenols in carbon tetrachloride. These values, in −kcal/mole, corrected for the temperature dependence of absorptivity coefficients, are Cl = 1.44, Br = 1.21, and I = 1.08. From enthalpy differences measured in unsymmetrical 2,6-dihalophenols, it is shown that the interaction in 2-fluorophenol lies between those in 2-bromophenol and 2-iodophenol, thus reaffirming the order Cl > Br > F > I.
A CHEMICAL STUDY OF BOCCONIA LATISEPALA WATS.
Authors: Dominguez Xorge Alejandro , Delgado Jesús Garcia , C. Alberto Monroy , Armendariz Luis G. , Alcala Abraham , Quevedo Josefina , Rojas Paulino
Published: May 2006

The Bocconia latisepala Wats., has been chemically studied. Each part was extracted separately with petroleum ether and with ethanol. The extracts were crystallized and purified by chromatographic methods. Cerylic alcohol was isolated from petroleum ether extracts of the bark, stems, and leaves. The bark and stems, leaves, roots, and seeds afforded the alkaloids chelerythrine, sanguinarine, protopine, α-allocryptopine, and oxysanguinarine, identified by their physical and chemical properties.
DECOMPOSITION OF THE ETHYL RADICAL AND THE MECHANISM OF THE PYROLYSIS OF n-BUTANE
Authors: Purnell J. H. , Quinn C. P.
Published: May 2006

not available
PROTONATED CARBONYL GROUPS: V. α-PYRIDONE SALTS
Authors: Cook Denys
Published: May 2006

Salts of 1-methyl-2-pyridone and 1-methyl-2-quinolone with strong acids have been prepared and their infrared spectra recorded between 4 000 and 650 cm−1. Protonation of the carbonyl group occurs giving rise to OH stretching, in-plane and out-of-plane bending vibrations which absorb in characteristic regions of the spectrum, namely 1 900 – 3 300 cm−1 (depending on the anion), ~ 1 250 cm−1, and ~ 800 cm−1 respectively, with appropriate shifts on deuteration. Other tentative assignments are made.
ENTROPY DIFFERENCES FOR SOME RELATED PAIRS OF COMPLEX IONS
Authors: Lin J. , Breck W. G.
Published: May 2006

The temperature coefficient of e.m.f. of a cell consisting of a saturated calomel electrode and a redox electrode of K4Fe(CN)6 and K3Fe(CN)6 has been determined by e.m.f. measurements at a series of equimolal concentrations of the above salts and at temperatures of 20, 25, 30, 35 °C. The results for this calomel–redox cell are expressed by the equation ECR0 = 0.1200 − 0.00214(t − 25), or for the redox electrode against a hydrogen gas electrode, EHR0 = 0.3644 − 0.00280(t − 25), with E in V and t in °C. Analogous results are available in the literature for other such pairs of complex ions; an examination of these data leads to the hypothesis that the following trichelated pairs: Fe dip32+/3+, Fe phen32+/3+, Ru dip32+/3+, are respectively nearly isentropic.
STEROIDS: IX. THE SOLVOLYSIS OF 4,4-DIETHYLCHOLESTERYL METHANESULFONATE
Authors: Gupta D. N. , Schilling G. , Just G.
Published: May 2006

The acetolysis of 4,4-diethylcholesteryl mesylate gave 11% 3,4-dialkyl (A), 39% 3α,5-cyclo (C), and 50% A-norcholestene (B) derivatives. The corresponding yield for the 4-4,dimethyl series is 25, < 11.6, and > 61.4%.
THE WALLACH REARRANGEMENT: PART II. KINETICS AND MECHANISM OF THE ACID-CATALYZED REARRANGEMENT OF AZOXYBENZENE
Authors: Buncel E. , Lawton B. T.
Published: May 2006

The rate of rearrangement of azoxybenzene to p-hydroxyazobenzene has been measured in 75.3–96.4% sulfuric acid at 25° and in 65.0–90.4% sulfuric acid at 75.5° by spectrophotometric methods. The pKa of azoxybenzene in aqueous sulfuric acid has also been determined. It is found that although azoxybesssnzene is almost completely protonated over the entire range of acid concentration studied, the rate increases by more than 1 000-fold. A two-proton process is therefore indicated and mechanisms are proposed involving a dication (II) as the key intermediate. The rate data do not allow differentiation between two proposed mechanisms, one involving two equilibrium protonations, and the other a single equilibrium protonation followed by rate-determining proton transfer. Past mechanisms of the Wallach rearrangement are discussed.
SLIP FLOW IN LONG, SINGLE CAPILLARIES: PART III. THE TRANSIENT STATE OF FLOW
Authors: Barrer R. M. , Nicholson D.
Published: May 2006

The time lag in establishing steady-state slip flow in long, single capillaries has been measured for the rare gases at 0 °C, for CO2, Xe, and propane at 196 °K, and for SO2 at 240 °K. The results are presented as non-dimensional time-lag quotients and as the reciprocals of this quotient plotted against u the reciprocal Knudsen number. Attention is drawn to some properties of reciprocal time lags, in particular the fact that they often have the same form as the permeability function when plotted against concentration. When adsorption is not appreciable, agreement between experiment and theory is very good in the slip flow regime but becomes less so as the transition regime is approached. Experiments at the lower temperatures showed that the effect of adsorption could be detected for CO2, Xe, and propane but not for SO2. These results can be interpreted in terms of a Freundlich isotherm but it seems probable that the time lag is particularly sensitive to the presence of sites of high adsorption potential.
THE USE OF POLYACRYLAMIDE GELS FOR CHROMATOGRAPHY OF PROTEINS
Authors: Sun K. , Sehon A. H.
Published: May 2006

Sixteen copolymers of acrylamide and N,N′-methylene bisacrylamide were synthesized using ammonium persulfate and dimethylaminopropionitrile as initiators. The water regain values of these gels were found to increase with decreasing total monomer concentration and with decreasing N,N′-methylene bisacrylamide/acrylamide ratio. The partition coefficients (Kd) of a variety of compounds of molecular weights between 104 and 580 000 were determined by normal elution column chromatography for three gels. The Kd values for a given solute using different gels were found to increase with decreasing total monomer concentration of the gel and with decreasing N,N′-methylene bisacrylamide/acrylamide ratio. For various solutes through the same column, the Kd values varied linearly with the logarithms of the corresponding molecular weights over the Kd range of 0.1 to 0.6. However, a number of compounds showed deviations from this relationship.
X-RAY POWDER PATTERNS FOR THE IDENTIFICATION OF SOME n-ALKANONE SEMICARBAZONES
Authors: Radell Jack , Brodman B. W. , Kramer Kimball
Published: May 2006

The interplanar spacings obtained from the X-ray powder patterns of a series of structurally related semicarbazones were used to unequivocally identify the ketones from which the derivatives were prepared. The advantages of the proposed over the currently used melting points to identify the compounds were cited. The method was found to be applicable to slightly contaminated mixtures of semicarbazones.
EFFECTS OF THE ELECTRONIC BAND SHAPE OF PALLADIUM METAL ON THE PROTON MODEL FOR HYDROGEN ABSORPTION
Authors: Simons J. W. , Flanagan Ted B.
Published: May 2006

The statistical treatment of the proton model for hydrogen absorption by palladium is extended to include a variation of the electron donation energy with hydrogen content, as determined by a density of states function for the combined 4d- and 5s-bands for palladium. This improved model gives better agreement with the high pressure limiting solubility data and the observed critical composition than the original model, when both are fitted to the critical isotherm by the same method. An apparent anomaly in the variation of the isosteric enthalpy of absorption with content is explained by the improved model.
ANALYSIS OF PRODUCTS FROM PERIODATE OXIDATION AND FROM METHYLATION OF A RHAMNAN
Authors: Dutton G. G. S. , Unrau A. M.
Published: May 2006

A synthetic L-rhamnan containing both rhamnofuranosyl and rhamnopyranosyl units has been used as a model substance in the application of vapor phase chromatography (v.p.c.) to the study of the structure of rhamnose containing polysaccharides. Groups of isomeric methylated sugars obtained from the methylated rhamnan were analyzed by converting them to methylated alditols which had widely different retention times. A Smith periodate degradation of the rhamnan gave 1,2-dihydroxypropane, 1-deoxy-D-erythritol, L-rhamnose, and 5-deoxy-L-arabinose, which were separated by paper chromatography. There were also obtained l-deoxy-3-O-(α-L-rhamnopyranosyl)-D-erythritol and the β-anomer, and 1-deoxy-2-O-(L-rhamnopyranosyl)-D-erythritol, separable by v.p.c. as their trimethylsilyl ethers. 1-Deoxy-D-erythritol was synthesized and characterized as the tri-p-nitrobenzoate. Of the terminal units in the synthetic rhamnan 35% were furanose and 2,3-di-O-methyl-L-rhamnose constituted 75% of the dimethyl fraction indicating that the principal linkage was (1 → 4).
ELECTROPHILIC CATALYSIS IN SOLVOLYTIC REACTIONS: VII. SOLVENT EFFECT
Authors: Anantaraman R. , Saramma K.
Published: May 2006

The rates of mercuric chloride catalyzed solvolysis of some alkyl chlorides in aqueous acetone and ethanol solvents have been compared. It is found that the increase in rate on changing from the acetone to the ethanol solvent is less in the catalyzed than in the normal reaction. On the basis that the electrophilic activity of the catalyst is less in aqueous ethanol than in aqueous acetone an explanation for the anomaly has been suggested. The effect, on the rates of solvolysis, of added chloride ions is in accord with the suggested explanation.
A QUASI-CRYSTALLINE MODEL OF DIFFUSION IN TERNARY LIQUID SYSTEMS
Authors: Lane J. E. , Kirkaldy J. S.
Published: May 2006

A quasi-crystalline model of a dilute ternary liquid system is proposed in which diffusion occurs by an interchange of species on neighboring lattice sites. Nonelectrolyte molecules are assumed to interchange with any type of diffusing species present in the system. In ternary nonelectrolyte systems relatively large cross-effects are associated with the mutual interchange of the two dilute solute species. The symmetry of the L-matrix arises directly through the application of detailed balance (microscopic reversibility) to this unit process.In electrolyte solutions, the only significant contribution to the ionic fluxes is expected to arise through interchange of ions with uncharged molecules. For diffusion in an aqueous solution of two strong electrolytes with a common ion, large off-diagonal L-coefficients result from the transformation of the lattice-referred diagonal diffusion matrix, written in terms of ionic fluxes and forces, to a form which relates the two independent salt fluxes and forces. Symmetry of the L-matrix in this case arises indirectly through the application of detailed balance to the ion-solvent interchanges. In aqueous electrolyte solutions the dilute solution ternary L-coefficients can be calculated from the independent individual ionic mobilities at infinite dilution, and these are found to be in excellent agreement with the experimental values for the system NaCl–KCl–H2O. The application of the model to binary electrolyte solutions at infinite dilution correctly yields the Nernst equation.The model is extended to solutions of two electrolytes with one or both incompletely ionized and to solutions containing a nonelectrolyte and a strong electrolyte. In all applications of the model the derived L-coefficients satisfy the well-known thermodynamic requirements. When appropriate ancillary data is available, the model yields fair to excellent predictions of the diffusion matrix at low concentrations of the solute species. Possible methods of improving the agreement at higher concentrations are discussed.
THE STRUCTURE OF BIS-DIMETHYLAMINOBERYLLIUM
Authors: Fetter Neil R. , Peters Frances M.
Published: May 2006

not available
PRESSURE-INDEPENDENT FLOW SYSTEM PYROLYSIS OF DIMETHYL CADMIUM
Authors: Krech M. , Price S. J.
Published: May 2006

The pyrolysis of CdMe2 has been investigated in a benzene carried flow system using temperatures from 743 °K to 800 °K and pressures from 1.63 cm to 16.2 cm. High pressure limiting rate constants were obtained above approximately 8 cm pressures. The high pressure activation energy, E0, of 48.8 ± 1 kcal/mole is identified with D(MeCd—Me) within the limits D < E0 < D + RT.
THE PYROLYSIS OF TRIMETHYLTHALLIUM
Authors: Jacko M. G. , Price S. J. W.
Published: May 2006

The pyrolysis of trimethylthallium has been studied in a toluene carrier flow system from 458 to 591 °K using total pressures from 5.6 to 33.0 mm. The progress of the reaction was followed by measuring the amount of methane, ethane, ethylene, and ethylbenzene formed and, in 21 runs, by direct thallium analysis. All preparative and kinetic work was carried out in total darkness where possible. A shielded 10 W lamp was used when some illumination was necessary.The decomposition is approximately 80% heterogeneous in an unconditioned vessel and 14–27% heterogeneous in a vessel pretreated with hot 50% HF for 10 min. The reaction proceeds by the simple consecutive release of three methyl radicals. The rate constant depends only slightly on the total pressure in the system so that the activation energy of the homogeneous process, 27.4 kcal/mole, may be equated to D[(CH3)2Tl—CH3].
THE ALCOHOLYSIS OF TRIALKYLALKOXYSILANES: PART I. A KINETIC STUDY OF THE METHANOLYSIS OF METHYL 2,3,4,6-TETRA-O-TRIMETHYLSILYL-α-D-GLUCOPYRANOSIDE TO FORM METHYL 2,3,4-TRI-O-TRIMETHYLSILYL-α-D-GLUCOPYRANOSIDE
Authors: McInnes A. G.
Published: May 2006

The selective methanolysis of the trimethylsilyl group on the primary 6-position of methyl 2,3,4,6-tetra-O-trimethylsilyl-α-D-glucopyranoside (I) to form methyl 2,3,4-tri-O-trimethylsilyl-α-D-glucopyranoside (II) is catalyzed by acid or base. In the latter case the reaction follows second-order kinetics in I and methoxide ion, and the rate of reaction is independent of the nature of the cation of the metal methoxide used to catalyze the reaction. Successive replacement of the methyl hydrogens in the methoxide ion by methyl groups is accompanied by a corresponding decrease in the rate of reaction. The rate constant for removal of trimethylsilyl groups at the secondary 2-, 3-, and 4-positions of I and II is smaller by a factor of 25 than for removal of the corresponding group at the primary 6-position, and the energies of activation for the two processes are 10.8 and 9.1 kcal mole−1.
THE STRUCTURE OF RETAMINE AND THE PARTIAL SYNTHESIS OF THE (−)-ENANTIOMORPH
Authors: Shin Kju Hi , Fonzes L. , Marion Léo
Published: May 2006

Previous work by many authors has led to the assumption that retamine might be (+)-12-hydroxysparteine. A partial synthesis of the enantiomorph of this compound has been effected by dehydration of (+)-13-hydroxylupanine and hydroboration of the product. The dehydration product consisted of two components that were separated by thin-layer chromatography and identified by the characteristics of their nuclear magnetic resonance (n.m.r.) spectra as Δ12,13-and Δ13,14-dehydrolupanine. Hydroboration of the Δ12,13-isomer gave rise to (−)-12-hydroxy-sparteine having, in thin-layer chromatography, the same Rf value as natural retamine and the same optical rotation numerically, although of opposite sign. The synthetic base had the same infrared and n.m.r. spectra as the alkaloid and the two had superimposable Debye–Scherrer patterns. Evidence is given showing the hydroxyl to be equatorial.
ACETONATION OF ALDOSE DIETHYL THIOACETALS
Authors: Gorin P. A. J.
Published: May 2006

Acetonation of hexose diethyl thioacetals using copper sulphate catalyst gave rise to 5,6-O-substituted products. The exception was D-galactose diethyl thioacetal, which underwent some 4,5-O-substitution. D-Threose and 2,3-di-O-methyl-D-galactose diethyl thioacetals also underwent predominant α-terminal substitution although some β-terminal substitution took place, particularly with the latter thioacetal. Acetone – sulphuric acid caused preferential α-T acetonation of D-threose and 2,3-di-O-methyl-D-galactose diethyl thioacetals. The product from D-threose diethyl thioacetal contained 90% of the 2,3-O-isopropylidene and 10% of the 3,4-O-isopropylidene derivatives.D-Glucurono-δ-lactone diethyl thioacetal in acetone – sulphuric acid acetonated mainly on the 2,4- positions although a smaller proportion of 4,5-O-isopropylidene derivative was present.
REACTIONS OF PHENYL-SUBSTITUTED HETEROCYCLIC COMPOUNDS. VI. NITRATION OF 5-PHENYLISOXAZOLE
Authors: Lynch Brian M. , Shiu Lizzie
Published: May 2006

not available