bluuebunny/crossref_metadata_2025 huggingface dataset:
THE STEREOCHEMISTRY OF MALEOPIMARIC ACID AND THE LONG RANGE SHIELDING EFFECT OF THE OLEFINIC BOND
Authors: Ayer W. A. , McDonald C. E. , Stothers J. B.
Published: May 2006

Nuclear magnetic resonance studies of methyl maleopimarate and closely related derivatives clearly establish the stereochemistry of methyl maleopimarate and, consequently, levopimaric acid. An extension of this study to other related compounds, 22 in all, provides evidence, on the basis of an intercomparison of the chemical shifts for the angular methyl protons, to support the original suggestion by Jackman (Applications of NMR in organic chemistry. Pergamon, New York. 1959. Chap. 7) that the long range shielding effect of the olefinic linkage is analogous to that of the carbonyl double bond. Coupling constants and chemical shifts for some of the protons of the bicyclo[2.2.2]octene system present in these compounds are also discussed.
THE REACTION OF CHLOROSULPHATE ESTERS OF SUGARS WITH PYRIDINE
Authors: Jennings H. J. , Jones J. K. N.
Published: May 2006

Hexoside and hexitol derivatives with vicinal chlorosulphate ester groups in different configurations were treated with pyridine. The corresponding cyclic sulphate esters were produced except in the case of the diaxial configuration, which gave an anyhdro derivative. The axial–equatorial configuration gave in addition a keto-deoxy compound. The structures of the cyclic sulphate esters and of other reaction products are proposed and their mode of formation is discussed.
THE NUCLEAR MAGNETIC RESONANCE SPECTRUM OF SODIUM METHYLCYCLOPENTADIENIDE
Authors: McLan Stewart , Haynes Peter
Published: May 2006

not available
ELECTRONIC EFFECTS IN ORGANOMAGNESIUM REACTIONS
Authors: Citron Joel D. , Becker Ernest I.
Published: May 2006

The kinetics of the first part of the reaction between para-substituted benzonitriles and diethylmagnesium have been studied. The rarely isolated intermediate products, the ketimines, have been isolated and identified. The kinetic constants fit a Hammett plot, with rho equal to + 1.57.
THE LOW-FREQUENCY DIELECTRIC PROPERTIES OF ETHYLENE OXIDE AND ETHYLENE OXIDE HYDRATE
Authors: Davidson D. W. , Wilson G. J.
Published: May 2006

The static dielectric constant of liquid ethylene oxide has been measured between 158 and 286 °K. The hydrate of ethylene oxide exhibits a dispersion–absorption region characterized by static dielectric constants about one-third as large as those of ice and by relatively large "high-frequency" dielectric constants (ε1 = 7.5 at 0 °C). This region may be approximately described as a circular arc locus, but may be represented somewhat better by a superposition of two (or three) semicircular dispersions. In either case, the activation energy for the relaxation of water molecules, to which this region is ascribed, is ca. 6.7 kcal/mole, except at low temperatures, where it becomes smaller. Experimental values of ε1 agree roughly with those calculated for comparatively rapid orientation of ethylene oxide molecules in the cavities of the hydrate. Such orientation may account for absorption maxima observed at 11 Mc/sec and above 100 Mc/sec at 90 °K.
THE SYNTHESIS OF D-glycero-D-manno-HEPTOSE
Authors: Hulyalkar R. K. , Jones J. K. N. , Perry M. B.
Published: May 2006

The condensation of D-altrose with nitromethane in alkaline methanol gave the corresponding epimeric 1-deoxy-1-nitroheptitols from which 1-deoxy-1-nitro-D-glycero-D-manno-heptitol was obtained in 46% yield. The 1-deoxy-1-nitro-D-glycero-D-manno-heptitol was converted to D-glycero-D-manno-heptose in 61% yield.
SOME NEW TRIARYLARSINES
Authors: Cullen W. R. , Yates Pamela E.
Published: May 2006

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STEROIDAL 3-CHLORO-3,5-DIENES
Authors: Moersch G. W. , Neuklis W. A.
Published: May 2006

not available
NOVEL SYNTHESIS OF 8-MERCAPTOQUINOLINE
Authors: Lee H. S.
Published: May 2006

not available
GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART VIII. THE VOLATILE OIL OF TANACETUM VULGARE L.
Authors: Rudloff E. von
Published: May 2006

The chemical composition of the commercial oil of tansy and of that obtained from a local tansy species was determined by means of gas–liquid chromatography. Both oils contained d-isothujone as the major component (68.5%, 58%). The commercial oil contained fairly large amounts of l-camphor (13.9%), whereas that from local plants had only traces of camphor and 19.8% of l-thujone. The minor components isolated and identified in both oils were l-α -pinene, l-camphene, d-sabinene, d-limonene, 1:8-cineole, γ-terpinene, p-cymene, d-terpinen-4-ol, l-carvotanacetone, and l-borneol. Small amounts of α-thujene, β-pinene, α-terpinene, terpinolene, neoisothujyl and isothujyl alcohols, and dihydrocarvone were identified by retention characteristics only. Car-4-ene, isomeric alloocimenes, and carvomenthone may also be present. An unknown, crystalline monoterpene alcohol with a terminal methylene group was isolated in small amounts. A sesquiterpene (3.7%) was obtained from the oil of local plants.Prefractionation of these oils by fractional distillation resulted in extensive isomerization of isothujone to dl-carvotanacetone. Such a rearrangement was not encountered during prefractionation by preparative gas–liquid chromatography.
AROMATIC SUBSTITUTION: PART II. THE REACTION OF VARIOUS 3-SUBSTITUTED PYRIDINE DERIVATIVES AND OF QUINOLINE WITH PHENYLLITHIUM
Authors: Abramovitch R. A. , Ahmed K. S. , Giam Choo-Seng
Published: May 2006

Phenyllithium and pyridine-3-N,N -diethylsulphonamide gave the expected 2-phenyl derivative exclusively. Contrary to a previous report some 2,3-diphenylpyridine is formed with 3-phenylpyridine. No pyridyne intermediate seems to be formed in the reaction of phenyllithium with 3-bromopyridine. The reactions of phenyllithium with quinoline and with N-benzylpyridinium chloride have also been studied and are discussed.
OCCURRENCE OF THE k PHASE AMONG CHALKOGENIDES
Authors: Knop Osvald
Published: May 2006

not available
DETERMINATION OF RELATIVE SIGNS OF COUPLING CONSTANTS IN QUINOLINE BY NUCLEAR MAGNETIC DOUBLE RESONANCE
Authors: Patersonand W. G. , Bigam G.
Published: May 2006

not available
HEATS OF VAPORIZATION OF A SERIES OF ALIPHATIC ALCOHOLS
Authors: McCurdy K. G. , Laidler K. J.
Published: May 2006

Heats of vaporization of 14 alcohols, having from one to five carbon atoms, have been determined in a Calvet microcalorimeter, using a special technique. The method consisted of allowing the alcohol to vaporize into a vacuum, the heat required for the vaporization being provided by passing a current through a resistance wire which was immersed in oil in a U-tube surrounded by the alcohol. The additivity scheme previously devised by Laidler for heats of formation and related properties was applied to the results, and the agreement with experiment was within a few tenths of a percent.
NEUTRON-DEFICIENT ISOTOPES OF LANTHANUM—La127, La128, La129, La130, and La131
Authors: Yaffe L. , Alexander J. M. , Hyde E. K.
Published: May 2006

La127, La128, La129, and La131 were produced by the reaction of C12 ions with antimony. Half-lives of 3.5 ± 0.5, 4.6 ± 0.6, 8.6 ± l.8, and 56 ± 3 min respectively, were obtained from the observed growth of the respective barium daughters. The half-life for Ba128 was found to be 2.43 ± 0.05 days. La129 and La130 were produced and identified by the reactions Ba130(p,2n) and Ba130(p,n) respectively, carried out with targets enriched in Ba130. In the proton bombardments half-lives of l0.0 ± 0.5 min and 8.7 ± 0.1 min were found for La129 and La130 respectively.
THE EXISTENCE OF THE FLEXIBLE CONFORMATION IN SIX-MEMBERED RINGS
Authors: Lautenschlaeger F. , Wright George F
Published: May 2006

From consideration of electrical polarization and nuclear magnetic resonance measurements, 1,4-dimethylenecyclohexane and its exo-tetramethyl and tetraphenyl analogues have been assigned the flexible ring conformation, as have also 1,4-dithiane and cis-1,4-dithiane-1,4-dioxide. However, the magnitudes of the moments indicate that uniform flexibility is not prevalent, the stretched form being predominant. In contrast to these flexible forms the conformation of dithiane monoxide is thought to be chair and that of 2,5-diphenyl-1,4-dithiin a fixed boat.
IONIZATION AND DISSOCIATION OF FORMATE ESTERS BY ELECTRON IMPACT
Authors: Raalte D. Van , Harrison A. G.
Published: May 2006

The mass spectra of methyl formate-d, ethyl formate-d, and isopropyl formate-d are compared with the mass spectra of the undeuterated compounds. By use of the deuterium labelling and appearance potential studies the dissociation reactions leading to a number of the oxygen-containing ions have been elucidated. The proton affinity of formic acid is estimated to be 157 kcal/mole from the appearance potential of the HC(OH)2+ ion in the mass spectra of ethyl formate and isopropyl formate.
THE SULPHUR–OXYGEN BOND IN SULPHURYL AND THIONYL COMPOUNDS: CORRELATION OF STRETCHING FREQUENCIES AND FORCE CONSTANTS WITH BOND LENGTHS, BOND ANGLES, AND BOND ORDERS
Authors: Gillespie R. J. , Robinson E. A.
Published: May 2006

It is shown that the bond length of an SO bond and the bond angle of an SO2 group may be very satisfactorily correlated with the SO stretching frequency. The bond-length – stretching-frequency relationship is used to predict some bond lengths that have not been measured and the OSO angles in some sulphuryl compounds are also calculated. The problem of defining and measuring the bond order of sulphur–oxygen bonds is discussed. It is shown that there is a linear relationship between the force constant and the bond order and a non-linear relationship between the bond length and the bond order.
THE PHOTOLYSIS OF SOME α-SUBSTITUTED CYCLOHEXANONES
Authors: Ferguson H. G. , Mayo P. De , Pattison F. L. M. , Tabata T.
Published: May 2006

not available
A NEW SYNTHETIC APPROACH TO THE BENZO[c]PHENANTHRIDINE SYSTEM: INTERNUCLEAR CYCLIZATION ONTO A PYRIDINE RING
Authors: Abramovitch R. A. , Tertzakian G.
Published: May 2006

Benzo[c]phenanthridine has been synthesized in low overall yield by the Pschorr cyclization of trans-α-(4-isoquinolyl)-o-aminocinnamic acid. The condensation of 4-isoquinolylacetonitrile with o-nitrobenzaldehyde gave the cis-cinnamonitrile. The preparation of a number of intermediates is described.
A GLUCAN PRODUCED BY CLAVICEPS PURPUREA
Authors: Perlin A. S. , Taber W. A.
Published: May 2006

A glucan is produced by pure cultures of Claviceps purpurea (Fr.) Tul., PRL 1980, and its formation appears to be related to the accumulation of other shunt products such as ergot alkaloids, polyols, and trehalose. The glucan consists of β-D-glucopyranosyl units, most of which constitute a (1 → 3)-linked main chain. Other units are attached as branches to units of the main chain by (1 → 6)-linkages and are distributed in a relatively uniform arrangement along the length of the polymer. The glucan is resistant to attack by an endo type of laminarinase but is degraded vigorously by one of the exo type, yielding D-glucose and gentiobiose.
BACK-SCATTERING AND SELF-ABSORPTION OF β−-PARTICLES
Authors: Lafleur M. S. , Kahana S. , Morris T. F. , Yaffe L.
Published: May 2006

The self-absorption of the β−-radiation from S35 and P32 has been studied in various compounds. The function derived by Gora and Hickey has been shown to fit the data. The back-scattering of the β−-radiation from P32 by various elements and compounds has been examined and a semiempirical treatment used to suggest an effective atomic number for back-scattering by compounds.
HETEROCYCLIC STEROIDS: II. PREPARATION AND N.M.R. SPECTRA OF 17,17-DIALKYL-13(14)-UNSATURATED STEROIDS
Authors: Caspi E. , Piatak D. M.
Published: May 2006

A series of 17,17-dialkyl-13(14)-unsaturated steroids was prepared via the Wagner–Meerwein rearrangement. Some of the steroids were synthesized with an isoxazole ring or a pyrazole ring attached to ring A. The n.m.r. spectra of the compounds prepared are discussed.
REACTIONS OF PHENYL-SUBSTITUTED HETEROCYCLIC COMPOUNDS: IV. BROMINATION OF 2-PHENYL-1,2,3,2H-TRIAZOLE
Authors: Lynch Brian M.
Published: May 2006

not available
THE STRUCTURE OF HYDRANGIN
Authors: Palmer K. H.
Published: May 2006

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THE PREPARATION OF 3-BROMOINDOLE
Authors: Piers K. , Meimaroglou C. , Jardine R. V. , Brown R. K.
Published: May 2006

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PERFLUOROALKYL ARSENICALS: PART VIII. REACTION OF ARSENIC SULPHIDES WITH PERFLUOROALKYL IODIDES
Authors: Cullen W. R.
Published: May 2006

(CH3)2AsSC2H5, prepared from (CH3)2AsCl and Pb(SC2H5)2, and ((CH3)2As)2S2 react with RfI at 100° to give the compounds (CH3)2AsRf (Rf = CF3, C3F7). The compounds AS2Sx (x = 2, 3) do not react with CF3I at 100°. ((CF3)2As)2S, prepared from (CF3)2AsI and Ag2S or from (CF3)2AsH and S, reacts with Hg to give ((CF3)2As)2, decomposes at 175° to give (CF3)3As, and reacts with CF3I at 125° to give mainly (CF3)3As. Some (CF3)2AsI and CF3SAs(CF3)2 is also produced from this last reaction.
PROTONATED CARBONYL GROUPS II. γ-PYRIDONE SALTS
Authors: Cook Denys
Published: May 2006

The salts of 1,2,6-trimethyl-4-pyridone and 1-ethyl-2,6-dimethyl-4-pyridone and mineral acids and their deuterated analogues have been prepared and their spectra recorded. The spectra are consistent with protonation at the carbonyl oxygen atom, not the nitrogen atom. Many similarities with the spectra of γ-pyrone salts (D. Cook. Can. J. Chem. 41, 505 (1963)) have been observed, voh varies from 2495 cm−1 in the HCl salt to 3470 cm−1 in the HPF6 salt. The deformation mode, vOH, is much more constant in frequency and is doubled, near 1300 and 1230 cm−1, probably due to correlation field splitting. A few of the more strongly hydrogen-bonded salts have torsional modes around 800 cm−1.Many of the salts can also be prepared in a hydrated form which contains the same organic cation, probably hydrogen bonded to chains of water molecules.In one case a salt containing 2 molecules of the base to 1 of acid (HAsF6) has been prepared. The spectrum contains a very broad, strong band, near 1300 cm−1, probably due to the species [Formula: see text].
ANALOGUES OF PSILOCIN AND LYSERGIC ACID DIETHYLAMIDE I. CHLORO, NITRO, AND AMINO DERIVATIVES OF 3-SUBSTITUTED INDOLES
Authors: McKay J. B. , Parkhurst R. M. , Silverstein R. M. , Skinner W. A.
Published: May 2006

A number of indole derivatives structurally related to either psilocin or lysergic acid diethylamide (LSD) were synthesized. The following structural analogues of psilocin are reported: 4-chloro-3-dimethylaminoethylindole, 4-nitro-3-dimethylaminoethylindole, 4-nitro-3-aminoethylindole, 4-amino-3-dimethylaminoethylindole, and 4-amino-3-aminoethylindole. Compounds structurally related to LSD that were synthesized are: 3-[β-carboxyethylaminoethyl]-4-nitroindole and 4-nitro-3-[N-methyl-N-(N′,N′-diethylcarboxamidoethy-aminoethyl]indole. Several 3,5- and 3,6-disubstituted indoles are also reported.
INVESTIGATION OF THE SELF-ASSOCIATION OF PHENOLS AND ANILINES BY ULTRAVIOLET SPECTROSCOPY
Authors: Dearden J. C.
Published: May 2006

Equations are derived for the calculation of the extent of self-association from ultraviolet absorption spectra. The spectra of a number of phenols and anilines have been taken over wide concentration ranges, and are discussed in terms of association. Association constants for four of the compounds have been calculated. An explanation of the spectral effects of self-association is offered.
GLYCOSIDATION OF SUGARS: II. METHANOLYSIS OF D-XYLOSE, D-ARABINOSE, D-LYXOSE, AND D-RIBOSE
Authors: Bishop C. T. , Cooper F. P.
Published: May 2006

Rates of methanolysis reactions of D-xylose, D-arabinose, D-lyxose, and D-ribose have been determined. It was found that methanolysis of a pentose proceeds to equilibrium through four distinguishable, competing reactions: (1) pentose → furanosides; (2) anomerization of furanosides; (3) furanosides → pyranosides; (4) anomerization of pyranosides. The glycoside compositions at equilibrium are interpreted in terms of stabilities of each of the four glycosides from each sugar as influenced by steric and ionic effects; a system of conformational analysis of furanoside rings is presented. The free energies of reaction in anomerization of pyranosides were in excellent agreement with values calculated from previously reported interaction energies in the pyranoid ring. The relative rates of the reactions were consistent with the view that non-bonded interactions in the methyl glycosides are relieved in the transition states for their interconversions.
TOSYLATED PEPTIDES AND p-NITROPHENYL ESTERS
Authors: Berse Casimir , Massiah Thomas , Piché Lucien
Published: May 2006

The tosyl group causes interference with mixed carbonic anhydride and p-nitrophenyl ester formation in certain instances. Several protected peptide sequences, occurring in the insulin molecule, and some tosylated p-nitrophenyl esters, have been prepared in the course of investigating this interference.
THE INHIBITED AUTOXIDATION OF STYRENE: PART III. THE RELATIVE INHIBITING EFFICIENCIES OF ORTHO-ALKYL PHENOLS
Authors: Howard J. A. , Ingold K. U.
Published: May 2006

The relative rates of reaction of a large number of ortho-alkyl phenols with styrylperoxy radicals have been measured at 65 °C. These groups have both an accelerating effect owing to their electron-donating character and a retarding effect which arises from steric factors. With two ortho-alkyl groups both the reaction rate and the overall polar contribution to the transition state decrease as the size of the alkyl groups is increased. A single o-t-butyl group produces a small enhancement of the reaction rate over and above its polar effect but this is not observed with any other alkyl groups.
STRUCTURAL STUDIES ON AN ARABINOXYLAN FROM PEA SKIN (PISUM SATIVUM): PART I. METHYLATION STUDIES
Authors: Banerji N. , Rao C. V. N.
Published: May 2006

The polysaccharide extracted by 4% sodium hydroxide solution from pea skin (Pisum sativum) was shown to be composed of D-xylose and L-arabinose in a ratio of 5:1. Hydrolysis of the fully methylated arabinoxylan yielded 2,3,5-tri-O-methyl-L-arabinose, 2,3-di-O-methyl-D-xylose, and 2-O-methyl-D-xylose in the molar ratio of 1:4.2:1.1 and traces of 2,3,4-tri-O-methyl-D-xylose and D-xylose. From these results and those of periodate oxidation studies, a structural formula for the arabinoxylan has been proposed.
THE REACTION OF t-BUTYL ALCOHOL VAPOR WITH Hg 6(3P1) ATOMS
Authors: Knight Arthur R. , Gunning Harry E.
Published: May 2006

The nature of the decomposition of t-butyl alcohol vapor, photosensitized by Hg 6(3P1) atoms in a static system at room temperature, has been examined under a variety of conditions of continuous and intermittent illumination. The inhibiting effect of nitric oxide has also been studied, as well as the influence of added inert gas.In the decomposition of pure substrate, the reaction products, with the initial quantum yields, Φ°, under continuous illumination in parenthesis, were: H2 (0.045), Me2CO (0.090), CO (0), CH4 (0.015), C2H6 (0.030) together with lesser amounts of C3H8, Me3CH, Me3CMe, and Me3COMe. On addition of nitric oxide, Me3CONO, Me2CO, N2O, N2, H2O, and trace quantities of H2 and CO were the only products observed.The reaction[Formula: see text]is proposed as the primary process in the decomposition and kinetic evidence is presented that the initially formed t-butoxy radicals possess excess energy and that their principal subsequent reaction is unimolecular cleavage into acetone and methyl. The results furthermore indicate that the substrate itself is quite inert to abstractive attack by the primary radicals.
THE EFFECT OF TIME AND TEMPERATURE ON THE HYDROGENATION OF ASPEN LIGNIN
Authors: Pepper J. M. , Steck Warren
Published: May 2006

A study has been made of the hydrogenation of preextracted aspen sapwood meal under conditions whereby the lignin is degraded to identifiable products. By gas liquid chromatography, guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-n-propylguaiacol, dihydroconiferyl alcohol, syringol, 4-methylsyringol, 4-ethylsyringol, 4-n-propylsyringol, and dihydrosinapyl alcohol were separated and identified.The relative abundance of these 10 compounds was determined in the chloroform-soluble product after hydrogenation using a dioxane–water (1:1) solvent medium, Raney nickel catalyst, an initial hydrogen pressure of 500 p.s.i. and temperatures of 150°, 165°, 185°, 195°, 210°, and 220° for a reaction time of 5 hours and a temperature of 195° for times of 0, 1.3, 5.0, and 24 hours. The best yield (52.2% of the Klason lignin) of such phenolic derivatives was obtained at a reaction temperature of 195° for 5 hours.The significance of the observed variation in the yields of these compounds with time and temperature and the relationship of these yields to the structure of lignin is discussed. Evidence is presented in support of both γ-alkyl ether and β-aryl ether linkages in the lignin substance.
THE MOLECULAR STRUCTURE OF HETERATISINE HYDROBROMIDE MONOHYDRATE
Authors: Przybylska Maria
Published: May 2006

not available
OXIDATION OF N, N-DIMETHYLANILINE: II. THE REACTION WITH OXYGEN CATALYZED BY BENZOYL PEROXIDE
Authors: Graham Donald M. , Mesrobian Robert B.
Published: May 2006

When benzoyl peroxide was used to initiate the reaction of oxygen with N,N-dimethylaniline, a chain reaction was shown to occur, resulting in an almost quantitative yield of hydrogen peroxide. The reaction was inhibited by mercaptan and benzoquinone, but not by hydroquinone, and was shown to be autoinhibited as well. The rate of oxidation was observed to be much greater in polar solvents, such as acetonitrile or methanol, than in non-polar solvents such as toluene and benzene. Diethyl- and dipropyl-aniline exhibited no chain characteristics under similar conditions, whereas dimethylbenzylamine and dimethyldodecylamine did not react at all.A mechanism has been postulated involving both semiquinone and peroxide chain carriers which is consistent with all of these observations. From an analysis of the oxidation rates in the presence and absence of mercaptan inhibition, the appropriate rate constants have been determined.
THE INFRARED AND RAMAN SPECTRA OF CYANOACETYLENE
Authors: Job V. A. , King G. W.
Published: May 2006

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METHYL α-FURANOSIDE DERIVATIVES OF FULLY METHYLATED GALACTOSE AND GALACTURONIC ACID
Authors: Walker Jr. H. G. , McCready R. M.
Published: May 2006

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CONVERSION OF A β-AMIDOESTER TO A PYRIMIDINE: 2-AMINO-4-HYDROXY-5,6,7,8-TETRAHYDRO-1,3,8-TRIAZANAPHTHALENE
Authors: DeGraw Joseph , Goodman Leon
Published: May 2006

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THE ISOBARIC BOILING POINTS OF THE SYSTEM: ACETIC ACID – CHLOROFORM – WATER AT A PRESSURE OF 760 mm Hg
Authors: Campbell A. N. , Gieskes J. M. T. M.
Published: May 2006

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REACTIONS OF BENZYLIDENETRIPHENYLPHOSPHORANE WITH SOME DICARBONYL COMPOUNDS
Authors: Parrick J.
Published: May 2006

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DOUBLE-MINIMUM POTENTIAL FOR INTRAMOLECULARLY HYDROGEN-BONDED PROTONS IN ORTHO-SUBSTITUTED ANILINES
Authors: Krueger P. J.
Published: May 2006

The concentration and temperature-independent splitting of the first overtone NH2 symmetric stretching band in 31 ortho-substituted anilines in which intramolecular hydrogen bonding is possible is interpreted in terms of a double-minimum potential for the hydrogen bonded proton. The intensity ratio of the doublet and the extent of the splitting is related to the basicity of the ortho-substituent, modified by the rigid geometrical restrictions of the intramolecular system. The absence of band splitting in the corresponding fundamental mode suggests that the secondary minimum lies in the vicinity of the v = 2 vibrational level. The antisymmetric mode appears to be less sensitive to perturbations.Deuteration studies, the spectra of some o-substituted N-methyl anilines, and the first over-tone bands of N-methyl aniline in very basic solvents support these views.
SUR LA DOUBLE ÉNOLISATION DE LA DIMÉTHYL-3,3 CYCLOHEXANONE
Authors: Champagne J. , Favre H. , Vocelle D. , Zbikowski Mlle I.
Published: May 2006

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A STUDY OF MOLECULAR INTERACTIONS IN MOLECULAR BEAMS ISOLATED FROM THE EXHAUST OF SUPERSONIC NOZZLES
Authors: Valleau John P. , Deckers Jacques M.
Published: May 2006

In high density molecular beams, such as those isolated from supersonic nozzles, collisions between beam molecules may have an important effect on the beam behavior. This paper uses the classical kinetic theory to discuss the effect of these collisions on the intensities and velocity distributions in a beam. Initially, intensities are calculated assuming unchanging Maxwellian velocity distributions. However, the beam collisions will, in fact, alter the velocity distributions in a way that could be described as an "asymmetric cooling" of the beam; a start has been made on examining the effects of this phenomenon.In the case of beams of mixed composition, the analysis indicates that an enrichment of the heavier component will take place as a result of collisions within the beam.Formulae relating beam density profiles to the geometry of the beam-defining elements are also deduced. Numerical examples are worked out for an illustrative case in which the diameter of the beam diaphragms is 0.1 cm and the distance between them is 10 cm, assuming the beam to be isolated from the exhaust of a 7.5 mach expansion with a stagnation temperature of 300° K.
PYROLYSIS STUDIES: X. RATES OF THE THERMAL DECOMPOSITION OF ortho-SUBSTITUTED ETHYL BENZOATES IN THE GAS PHASE
Authors: Smith Grant Gill , Brown David F.
Published: May 2006

Eight ortho-substituted ethyl benzoates (with substituents varying from o-NH2 to o-NO2) have been partially pyrolyzed to ethylene and the corresponding benzoic acid. By gas chromatographic measurement of the amount of ethylene produced, the relative rates of the thermal decomposition of the various ethers have been determined. There are minor steric effects (primary or secondary) in the reaction and direct field influences are negligible. The varying reactivity, therefore, is attributed to changes in polar effects of the substituent. This reaction appears to be a useful method of determining, quantitatively, to a good first approximation, polar effects of ortho substituents.
THE RAMAN SPECTRA OF DEUTERATED METHYL LAURATES AND RELATED COMPOUNDS
Authors: Jones R. Norman , Ripley R. A.
Published: May 2006

The Raman spectra of methyl laurate and five derivatives selectively deuterated in the terminal methyl group, the α-methylene group, and the carbomethoxy group have been examined in the liquid phase. Raman spectra of n-dodecane and n-dodecane-1,12-d6have also been determined. The spectra are compared with the infrared spectra, which have been reported previously, and are analyzed in terms of current views on the vibrations of compounds containing polymethylene chains.Whereas the infrared spectra of the esters are dominated by absorption bands associated with the carbomethoxy group, this group has only a minor effect on the Raman spectrum; the implications of this in organic structural analysis are discussed.
SPECTROSCOPIC STUDIES OF ALCOHOLS: III. FUNDAMENTAL OH STRETCHING BANDS OF 2,2-DI- AND 2,2,2-TRI-HALOETHANOLS
Authors: Krueger P. J. , Mettee H. D.
Published: May 2006

The OH stretching region was examined for the compounds F3CCH2OH, Cl2CHCH2OH, Cl3CCH2OH, and Br3CCH2OH in dilute CCl4 solution. The first two compounds exhibit temperature-dependent band asymmetry which is due to trans–gauche equilibria arising from rotation about the C—O bond, with relatively small populations in the trans forms. Enthalpy differences of 3.3 and 2.4 kcal/mole between the conformers were obtained for these two compounds respectively. Although symmetrical at lower temperatures, the band for Cl3CCH2OH shows the presence of a small amount of the trans conformer at temperatures above 45 °C. These results are discussed in terms of intramolecular OH … X hydrogen bond interaction, inductive effects, non-bonded interactions, O—H bond polarization, C—X bond polarizability, and the size of the halogen atoms in a geometrically constrained system.
SPECTROSCOPIC STUDIES OF ALCOHOLS: IV. CONFORMATIONAL HETEROGENEITY OF 1-PROPANOL IN DILUTE CCl4 SOLUTION
Authors: Krueger P. J. , Mettee H. D.
Published: May 2006

High-resolution infrared spectroscopy indicates that the fundamental OH stretching band of 1-propanol in dilute CCl4 solution is composed of three components caused by rotational isomerism about the C—C and C—O bonds. Although the conformer with the CH3 and OH groups trans to each other is most heavily populated at room temperature, one of the two conformers having gauche CH3 and OH groups is thermodynamically most stable. A conformational equilibrium scheme is postulated in which the most stable conformer has a methyl C—H interacting with one of the lone pairs of electrons on the oxygen atom.
MOLD METABOLITES: 3. THE STRUCTURE OF THE GRISEOVIRIDIN SALTS
Authors: Fallona M. Catherine , Mayo P. de , Stoessl A.
Published: May 2006

The conversion of griseoviridin (I) into its hydrochloride and into its perchlorate has been shown to involve the ejection of one of the hydroxyl groups in (I) and the formation of an imino-lactone salt.
SYNTHESIS OF 2- OR 4,6-DINITRO-sec-PENTYL PHENOLS
Authors: Dutton G. G. S. , Hillman M. E. D. , Moffatt J. G.
Published: May 2006

not available
A SIMPLE PREPARATION OF 5,6-DIHYDROXY-N-METHYLINDOLE
Authors: Mattok G. L. , Heacock R. A.
Published: May 2006

not available
NUCLEAR MAGNETIC RESONANCE STUDIES OF THE PROTONATION OF WEAK BASES IN FLUOROSULPHURIC ACID: III. METHYLBENZENES AND ANISOLE
Authors: Birchall T. , Gillespie R. J.
Published: May 2006

The proton magnetic resonance spectra of solutions of mesitylene, durene, pentamethylbenzene, hexamethylbenzene, m- and p-xylenes, and anisole have been studied in fluorosulphuric acid and protonation on the ring carbon atom established. Rates of proton exchange have been measured and activation energies calculated for the proton exchange process. Intermolecular exchange with the solvent is suggested as the most probable exchange process in all cases.
THE PREPARATION OF THE HYDROXYSKATOLES AND 5,6-DIHYDROXYSKATOLE
Authors: Heacock R. A. , Hutzinger O.
Published: May 2006

A new procedure for the preparation of the hydroxyskatoles has been devised. 4-, 5-, 6-, and 7-benzyloxyindole-3-carboxaldehyde and 5,6-dibenzyloxyindole-3-carboxaldehyde have been prepared and give the corresponding benzyloxyskatoles on reduction with either LiAlH4 or NaBH4/Pd–C. The 4-, 5-, 6-, and 7-hydroxyskatoles and 5,6-dihydroxyskatole are readily obtained on catalytic debenzylation of the relevant benzyloxy compound. An alternative method for the preparation of the hydroxyskatoles involving hydrogenolysis of the benzyloxygramines is also described.The possible structures of by-products obtained in some instances are discussed.
THE BROMINOLYSIS OF CARBOHYDRATE IODIDES: II. A SYNTHETIC ROUTE TO 2,5-ANHYDROSUGARS
Authors: Lemieux R. U. , Fraser-Reid B.
Published: May 2006

Reaction of methyl 2-deoxy-2-iodo-β-D-glucopyranoside triacetate with a 20-fold excess of bromine and a 10-fold excess of silver acetate in a 10% solution of potassium acetate in acetic acid gave a near-quantitative yield of an equimolar mixture of the anomeric forms of 1,3,4,6-tetra-O-acetyl-2,5-anhydro-1-methoxy-D-mannose. Treatment of the mixture with methanolic hydrogen chloride gave the dimethylacetal of 2,5-anhydro-D-mannose (chitose).
OXIDATION–REDUCTION POLYMERS: III. STANDARD OXIDATION POTENTIALS OF 2,5-DIHYDROXYDIPHENYL SULPHONES
Authors: Spinner I. H. , Kasserra H. P. , Metanomski W.
Published: May 2006

The preparation of two new sulphonyl derivatives of methoxy- and naphtha-hydroquinone as possible intermediate compounds in the synthesis of redox monomers is described. The standard oxidation potentials of these and other sulphonyl derivatives of hydroquinones were determined and compared with the values for similar compounds, reported previously (1).
RADIATION CHEMISTRY OF CYCLOHEXANE: VI. DILUTE SOLUTIONS OF CARBON TETRACHLORIDE AND CHLOROFORM IN CYCLOHEXANE
Authors: Stone J. A. , Dyne P. J.
Published: May 2006

A study of the effect of the addition of small amounts (<3.5%) of the halogenated compounds CCl4, CHCl3, and CDCl3 on the radiolysis of cyclohexane has shown that processes other than radical scavenging occur. At the lowest concentrations of solute that it was practical to employ (0.004 M) cyclohexyl radicals were scavenged without a corresponding reduction in the hydrogen yield. At higher solute concentrations G(H2) was reduced by a physical process which did not involve the scavenging of thermal hydrogen atoms but did lead to chemical reaction involving the solute.
SOME REACTIONS OF ALICYCLIC α-AZIDOKETONES
Authors: Edwards O. E. , Purushothaman K. K.
Published: May 2006

not available
THE pKa OF PROTONATED α,β-UNSATURATED CARBOXYLIC ACIDS
Authors: Sorensen T. S.
Published: May 2006

The pKa of three, protonated α,β-unsaturated carboxylic acids have been determined from their ultraviolet absorption curves by using several of the well-known empirical methods. A detailed study of the absorption curves has been attempted in order to learn more about the "solvent effect" inherent in this spectral method of calculating pKa values. Methyl substitution at the β-carbon of the acid results in large differences in the calculated pKa.
POLYCONDENSED ANIONS OF THE TRANSITION METALS: LIGHT SCATTERING AND ULTRACENTRIFUGATION WITH SCHLIEREN AND INTERFERENCE OPTICS OF ALKALINE NIOBIUM (V) SOLUTIONS
Authors: Nelson Wilfred H. , Tobias R. Stuart
Published: May 2006

Alkaline aqueous niobium(V) solutions prepared by dissolving the salt K14Nb12O37•27H2O were studied by means of light scattering and by equilibrium ultracentrifugation by using both schlieren and interference optics. All three experimental methods indicate that the degree of polymerization of the polycondensed niobate anion is no less than 5 and probably has the value 6. The centrifugation data indicate that only one polycondensed species exists in the solutions. The effective charge of the niobate anion appears to be reduced appreciably by the binding of potassium ions to a value of no greater than −2. The behavior of the solutions is very similar to that observed previously with alkaline tantalum(V) solutions, and it appears very likely that the hexameric anion [HNb6O19]−7 found in niobate crystals also exists in aqueous solutions. The niobate is slightly protonated in comparison to the analogous tantalate. The stability of highly concentrated solutions containing this large polycondensed species is probably the result of the existence of a poly-ion with high symmetry which interacts only weakly with the solvent, water.
N,N-DIACETYLAMINES AS BY-PRODUCTS FROM THE ACETYLATION OF AMINES
Authors: Bannard R. A. B.
Published: May 2006

Acetylation of five alicyclic amines and isopropylamine with a large excess of acetic anhydride for 1 hour under reflux led to formation of appreciable yields (23–35%) of N,N-diacetylamines in addition to the anticipated N-acetylamines, except in the case of cis-2-aminocyclohexanol, which gave only the O,N-diacetyl derivative. The N-acetyl derivatives show an acetamido methyl proton resonance in their nuclear magnetic resonance spectra at 8.04–8.09 τ, whereas the N,N-diacetylamines show no absorption in this region but instead a resonance equivalent to six protons at 7.63–7.69 τ due to the N,N-diacetyl group. The infrared spectra of these compounds are consistent with the structures assigned on the basis of their n.m.r. spectra. Splitting of the amide carbonyl band was not generally observed in these compounds although two of the substances exhibited a minor band on the low frequency side of the main band which might be attributed to this cause.
THE EFFECT OF WATER VAPOR UPON THE DEHYDRATION OF CaSO4•2H2O
Authors: McAdie H. G.
Published: May 2006

Kinetics of the two-stage dehydration of CaSO4•2H2O have been examined under controlled water vapor pressures up to one atmosphere. For both stages water vapor initially accelerated the rate of dehydration and subsequently retarded it. Separate, temperature-dependent water vapor pressures were noted above which each stage could be suppressed.The hemihydrate was clearly defined either as a change in the rate of weight loss during dehydration or, at higher water vapor pressures, as a fixed composition. The heat of solution of the hemihydrate increased linearly with the partial water vapor pressure present during its formation, but was independent of the formation temperature over the range studied. Activation energy and pre-exponential factor for the dihydrate → hemihydrate process also increased linearly with water vapor pressure. Hemihydrates produced at the extremes of water vapor pressure corresponded to the α- and β-modifications, as defined thermodynamically, and the production of a hemihydrate series with properties varying linearly from one extreme to the other is discussed.
RATES OF POLYMERIZATION OF ACRYLATES AND METHACRYLATES IN EMULSION SYSTEMS
Authors: McCurdy K. G. , Laidler K. J.
Published: May 2006

The microcalorimeter has been used to obtain rates of polymerization of a number of monomers in emulsion systems. The rates with the acrylates are consistently higher than those with the methacrylates, and this is attributed to less steric hindrance. Low rates found with monomers containing a hydroxyl group are explained as due to solvation in the initial state. In both the acrylates and methacrylates the rates go through a maximum as one goes up the series methyl: ethyl: butyl: hexyl. This is discussed in terms of inductive and steric effects.
EFFECTS ON THE N.M.R. SPECTRA OF THE STEREOCHEMISTRY OF 3,4-DIARYLADIPIC ESTERS AND 1,2-DIARYLCYCLOPENTANES
Authors: Curtin D. Y. , Dayagi S.
Published: May 2006

Examination of the n.m.r. spectra of cis- and trans-1,2-diphenylcyclopentane and 3,4-diphenylcyclopentanone substituted in the para positions of both rings with methoxyl, methyl, and chloro substituents has shown that the previous explanation (1) of the effect of temperature on the n.m.r. spectra of 1,2-diphenylcyclopentane and 3,4-diphenylcyclopentanone (unsubstituted) was incorrect. The n.m.r. spectra provide no evidence of restriction of rotation of the aromatic rings of these compounds. An alternative explanation is offered.Comparison of the spectra of the compounds above and those of meso- and dl-3,4-diphenyl-adipic esters with the para substituents mentioned leads to the observation that in the dl-adipates and the cis-cyclopentanes the position of absorption of the protons ortho to the central structure (HR) is shifted to higher field compared to the corresponding meso or trans isomer by an amount ranging from 0.2 to 0.7 p.p.m. The protons ortho to the substituent X (HX) are also shifted to higher field but by only about 0.1 p.p.m.Shifts of the benzylic protons of the trans-cyclopentanes and cyclopentanones to higher field amount to 0.3–0.6 p.p.m. in agreement with previous work (1, 34). The corresponding shift of the benzylic protons of the meso-adipic esters is only 0.1–0.2 p.p.m. The methylene protons and the methyl ester protons of the meso-adipates are also shifted to higher field by about 0.3 and 0.2 p.p.m. respectively.These shifts seem adequately explained in terms of ring current effects of the benzene rings and lead to the possibility of obtaining detailed information concerning the stereochemistry of such substances. They are of immediate value in making configurational assignments to related compounds.
PROTON MAGNETIC RESONANCE ABSORPTION IN COPPER(II) STEARATE
Authors: Grant R. F.
Published: May 2006

not available
REACTION OF BENZALDEHYDE SEMICARBAZONE AND AZINE WITH CARBON MONOXIDE
Authors: Rosenthal Alex , Millward S.
Published: May 2006

not available
6,7-DI-2′-PYRIDYLDODECANE
Authors: Edward J. T.
Published: May 2006

not available
NEPHELOMETRIC DETERMINATION OF PALLADIUM WITH DI-2-THIENYLKETOXIME
Authors: Holland William J. , Lee Leo
Published: May 2006

Di-2-thienylketoxime is used to determine 1 to 4 p.p.m. of palladium nephelometrically. Palladium (II) can be determined in the presence of a 30-fold excess of platinum. A sixfold excess of other platinum metals and gold do not interfere. No interference was found with other common cations or anions with the exception of cyanide.
THE GLUCOMANNAN OF BLUEBELL SEED (SCYLLA NONSCRIPTA L.)
Authors: Thompson J. L. , Jones J. K. N.
Published: May 2006

A glucomannan has been isolated from bluebell seeds. It is a linear polymer composed of D-glucopyranose and D-mannopyranose residues in the approximate ratio of 1:1.3. Methylation and periodate oxidation results support this structure. Acetolysis of the polysaccharide led to the isolation of cellobiose, 4-O-β-D-mannopyranosyl-D-glucose and 4-O-β-D-glucopyranosyl-D-mannose.
PROTON MAGNETIC RESONANCE ABSORPTION IN HIGH TEMPERATURE PHASES OF ANHYDROUS SODIUM STEARATE
Authors: Barr M. R. , Dunell B. A.
Published: May 2006

Nuclear magnetic resonance spectra of anhydrous sodium stearate have been observed between 114° and 320 °C. The observed changes in line width and second moment suggest a grouping of the mesomorphic phases into a waxy group in which a lattice structure is preserved for the polar ends of the molecules and a group consisting of the neat and liquid phases in which diffusion takes place freely.
THE RELATIVE ACID STRENGTHS OF SUBSTITUTED PICRIC ACIDS
Authors: Elder John W. , Mariella Raymond P.
Published: May 2006

The relative acidity of substituted picric acids has been determined using special non-aqueous titration techniques. Other organic and inorganic acids, whose acidities in water are well known, were also determined using this non-aqueous method. A correlation of the relative acidities of known acids in water with the relative acidities of these same acids, as measured under the non-aqueous conditions used, was excellent. Using this technique a single relative acidity scale was determined ranging from acids as strong as perchloric to acids as weak as acetic acid.
AN ULTRASONIC STUDY OF SOME OF THE COMPLEXING REACTIONS OF CHLORIDE WITH CADMIUM ION
Authors: Valleau J. P. , Turner S. J.
Published: May 2006

The ultrasonic absorptions of 0.25 M aqueous solutions of cadmium ions, containing various amounts of hydrochloric acid, have been measured by a pulse technique between 13 and 143 Mc/second at 16°, 25°, and 35 °C. A relaxation occurs in this region, and it has been interpreted in terms of the interacting association reactions[Formula: see text]An ultrasonic determination of the equilibrium quotient of the second of these reactions has been made, and the association and dissociation rate constants are reported for both reactions. In addition, the volume changes, ΔV, in the two reactions have been estimated, along with the activation energy for the dissociation of CdCl3−. The analysis breaks down at low ligand concentrations, and this is ascribed to the influence of a third interacting reaction.
DISPLACEMENT OF C4-HYDROCARBON MOLECULES ADSORBED ON PLATINUM
Authors: Affrossman S. , Cvetanović R. J.
Published: May 2006

A special technique has been used in an attempt to determine the nature and the amount of the C4-hydrocarbons desorbed by displacement with "poisons" (CO, CS2) from the "active" sites of a platinum on asbestos hydrogenation catalyst. The "active" area of the catalyst determined in this way is found to decrease with increasing adsorption of the poison molecules, and is approximately related in the expected manner to the observed catalytic activity for butene hydrogenation. The likely nature of the adsorbed hydrocarbon species is discussed.
THE CONFIGURATION AND CONFORMATION OF "DI-D-FRUCTOSE ANHYDRIDE I"
Authors: Lemieux R. U. , Nagarajan R.
Published: May 2006

"Di-D-fructose anhydride I", obtained by acid depolymerization of inulin triacetate, was found to be 1′,2-anhydro-[1-(α-D-fructofuranosyl)-β-D-fructofuranose]. The high resistance to oxidation by periodate found for the α-D-fructofuranoside portion was related to the conformation for the ring wherein the 3′- and 4′-hydroxyl groups are in quasi-axial orientation. This and other conclusions about the conformations of the anhydride were based on a comparison of the 100 Mc.p.s. proton magnetic resonance spectra of the 6,6′-dideoxytetra-O-acetyl derivative of the anhydride, sucrose octaacetate, and 1,6-anhydro-α-D-galactofuranose triacetate.
MULTISTAGE DEACTIVATION IN THE PHOTOLYSIS OF HEXAFLUOROACETONE
Authors: Strachan A. N. , Boyd R. K. , Kutschke K. O.
Published: May 2006

In principle the vibrationally excited molecule in an upper electronic state, formed by absorption in the ultraviolet region of the spectrum, can attain vibrational equilibrium by two mechanisms. In most discussions of this degradation of vibrational energy it has been considered that the data are represented adequately by a single-step deactivation from high to low vibrational levels rather than by a multistep cascade from one group of vibrational levels to the next lower group. The present work suggests new treatments of the experimental data by which it is possible to distinguish between the single- and the multi-step deactivation processes. It is demonstrated that the literature data on the quantum yield for the decomposition of hexafluoroacetone is better interpreted in terms of a multistep deactivation. Some new data are presented which support this conclusion.Methods to evaluate the efficiencies as deactivating agents of added inert gases are discussed. It is suggested that the deactivation of excited hexafluoroacetone by hydrocarbons might involve chemical rather than, or in addition to, purely physical quenching.
INTRAMOLECULAR DIAZO COUPLING AND MOLECULAR REARRANGEMENT OF o-AMINOPHENYLCARBINOLS
Authors: Cohen Robert L. , Sisti Anthony J.
Published: May 2006

A number of 1-(2-aminophenyl)-1-(substituted aryl)ethanols were deaminated, yielding ketones, formed by a molecular rearrangement and, in some instances, azo ketones formed by intramolecular coupling and cleavage. The sensitivities of these two reactions, one characteristic of the aryl cation and the other of the diazonium group, to relatively small changes in the electrical nature of the migrating group were determined.
THE INTERACTION OF o-DIPHENOLS WITH α-DIKETONES: THE REACTION OF 5,6-DIHYDROXY-N-METHYLINDOLE WITH DEHYDROASCORBIC ACID
Authors: Mattok G. L. , Heacock R. A.
Published: May 2006

5,6-Dihydroxy-N-methylmdole readily reacts with dehydroascorbic acid in aqueous solution at room temperature. The o-diphenol system of the indole derivative interacts with the α-diketone function of dehydroascorbic acid to form a 1,4-benzodioxane derivative. This type of reaction appears to be a general one since similar interactions occur between other o-diphenols and α-diketones. The mechanism by which the 1,4-benzodioxane derivative is obtained when adrenochrome is reduced with ascorbic acid is discussed.
FISSION FRAGMENT IRRADIATIONS OF HYDROCARBONS: I. YIELD AND ISOTOPIC COMPOSITION OF HYDROGEN FROM MIXTURES OF CYCLOHEXANE AND BENZENE WITH THEIR DEUTERATED ANALOGUES
Authors: Boyd A. W. , Connor H. W. J.
Published: May 2006

Cyclohexane and benzene and mixtures of each of these with cyclohexane-d12 and benzene-d6 have been irradiated with fission fragments using thin sources of [Formula: see text]. The hydrogen yield G(H2) for cyclohexane is 7.73, and is only slightly reduced by the addition of benzene. G(H2) for benzene is 2.14. The isotopic composition of the hydrogen from the four mixtures indicates that most is formed in bimolecular processes.To correlate these results with those obtained in gamma radiolysis, a mechanism is proposed based on hydrogen formation by reactions between transient species in both cyclohexane and benzene.
SYNTHESIS OF 4-TRIFLUOROMETHYLPHTHALIC ACID
Authors: Love Bernard
Published: May 2006

not available
BONDING IN THE SULPHITE ION
Authors: Robinson E. A.
Published: May 2006

not available
CONFORMATIONAL STUDIES OF THE CYCLOHEXANE RING BY NUCLEAR MAGNETIC RESONANCE. VII. THE REACTION OF 1,4-CYCLOHEXANEDIOL WITH CONCENTRATED HYDROCHLORIC ACID
Authors: Premuzic E. , Reeves L. W.
Published: May 2006

not available