bluuebunny/crossref_metadata_2025 huggingface dataset:
THE PHOTOLYSIS OF DEUTERATED ACETONE AND OF DEUTERATED ACETONE–HYDROGEN MIXTURES
Authors: Henderson J. F. , Steacie E. W. R.
Published: May 2006

The photolyses of acetone, acetone-d6, and acetone-d6 – hydrogen mixtures were investigated at 471 °K. The rates of formation of methane, ethane, and carbon monoxide and the ratio [Formula: see text] were independent of the fractional amount of acetone which photolyzed, as measured by 100[CO]/[A]0, which was varied from <1% to 18%. When the acetone-d6–hydrogen mixtures were photolyzed, [Formula: see text] and [Formula: see text] were observed to be functions of [A]0 and [H2]0. It is postulated that some of the CD4 and CD3H was formed by a reaction between methyl radicals and an excited molecule which contained both C—D and C—H bonds.
REACTION OF OXYGEN ATOMS WITH BUTADIENE
Authors: Cvetanović R. J. , Doyle L. C.
Published: May 2006

Reaction of oxygen atoms with 1,3-butadiene has been investigated at room temperature. It is found that it conforms to the general mechanism established previously for the analogous reactions of monoolefins. Only 1,2-addition occurs, and the addition products, butadiene monoxide and 3-butenal, possess excess energy when formed as a result of high heats of reaction. The pressure dependence of the formation of the addition products yields the values of the "lifetimes" of the initially produced "hot" molecules. The relative rate constants have been determined at 25 and 127 °C and from these the relative values of the Arrhenius parameters have been calculated.
CHEMICAL SHIFTS IN THE N.M.R. SPECTRA OF SUBSTITUTED XYLENES
Authors: Fraser Robert R.
Published: May 2006

The complete results of analysis of the N.M.R. spectra of twelve 2,6-dimethyl-1-substituted benzenes are reported. The results are interpreted as evidence that the ability of the substituent to donate or withdraw electrons by resonance interaction with the benzene ring is a major factor in determining the position of absorption of the protons attached to the ring. The chemical shifts and coupling constants for nitroethylene are also reported.
THE MECHANISMS OF PERMANGANATE OXIDATION VI. THE OXIDATION OF CYANIDE ION
Authors: Stewart Ross , Linden R. Van der
Published: May 2006

Kinetic and oxygen-18 tracer experiments have been used in an attempt to elucidate the mechanism(s) of permanganate oxidation of cyanide. From pH 12 to 14.6 the oxidation is represented by the equation,[Formula: see text]From pH 12 to 6 the reaction was found to be complex and unstoichiometric yielding cyanate, carbon dioxide, cyanide ion, and finally cyanogen at pH 9 to 6.The rate of reduction of permanganate, as followed iodometrically and spectrophotometrically, is found to be markedly dependent on the pH of the medium and reactant concentration. The rate is negligible in acid solution but rapid in basic media.At pH greater than 12 two parallel processes are indicated which have been designated as reaction A and reaction B. Reaction A appears at low reactant concentrations 0.0004 M cyanide and higher hydroxyl ion concentrations pH 13 and is represented by the kinetic expression[Formula: see text]where k2 is independent of hydroxyl ion concentration and is insensitive to the presence of manganate and barium ions. A positive salt effect is observed and labeling experiments using permanganate enriched in oxygen18 showed that the oxygen introduced into the product cyanate comes mainly from the oxidant (70%–80% oxygen-18 transferred).The existence of a second process reaction B was indicated by the changing kinetics at higher reactant concentrations and lower basicities, by the non-linear Arrhenius plots, and by the observation that only 15–25% oxygen-18 transfer from permanganate to substrate had occurred at pH 13. The rate of this latter process is approximately represented by the kinetic expression[Formula: see text]These reactions are discussed in terms of mechanism
PRIMARY QUANTUM EFFICIENCIES IN THE REACTION OF CYCLOPENTANE WITH MERCURY 6(3P1) ATOMS
Authors: Stock Richard L. , Gunning Harry E.
Published: May 2006

An investigation has been made of the reaction of cyclopentane with Hg 6(3P1) atoms at a substrate pressure of 107 mm, under static conditions at 24 °C. Low light intensities were used in order to minimize secondary reactions.The products of the reaction, for small extents of decomposition, have been shown to be exclusively hydrogen, bicyclopentyl, and cyclopentene. With increasing duration of exposure, the cyclopentene-to-cyclopentane ratio achieves a steady-state value of 5.7 × 10−3. Furthermore, it has been found that the same ratio is ultimately reached, upon prolonged exposure of a substrate initially containing cyclopentene at a concentration higher than the steady-state value. In the runs with added cyclopentene, a fourth product appeared in measurable quantities. Its molecular weight corresponded to the formula, C10H16, and it was assumed to be a cyclopentyl cyclopentene. The same compound appears in extensive decomposition of the pure substrate.The addition of small amounts of nitric oxide was found to have a marked inhibiting effect on the reaction. Bicyclopentyl formation was completely suppressed when 0.7 mole% of nitric oxide was present; and the cyclopentene yield was reduced to one-fifth of its value for the pure substrate, by adding 0.98 mole% of nitric oxide.In order to obtain primary quantum yields for the reaction, a series of runs were performed of 1 to 33 minutes in duration, with a cyclopentane which had been purified by gas–liquid chromatography. By a short extrapolation of the mean quantum yields of product formation to zero extent of reaction, it was found that the primary quantum yields for hydrogen, bicyclopentyl, and cyclopentene were respectively 0.8, 0.4, and 0.4.On the basis of a simple four-step paraffinic mechanism, taken in conjunction with the primary quantum yield data, it is concluded that the reaction has a primary quantum yield of substrate decomposition of 0.8, and that cyclopentyl radicals have the same rates for disproportionation and recombination at 24 °C.
REARRANGEMENT STUDIES WITH C14. X. ETHANOL-2-C14 FROM THE IRRADIATION OF ETHANOL-1-C 14 WITH Co60 GAMMA RAYS
Authors: Lee C. C. , Lee D. G.
Published: May 2006

The irradiation of aqueous solutions of ethanol-1-C14, containing about 2% ethanol by weight, with up to 58.0 million rads of Co60 γ-rays led to the formation of up to 0.49% ethanol-2-C14 in the alcohol recovered after irradiation. The G value of this isotope position rearrangement was about 0.04 and amounted to approximately 2% of the G value for the total amount of ethanol decomposed. Possible mechanisms for the rearrangement are discussed.
CELLULOSE COLUMN CHROMATOGRAPHIC SEPARATION OF LIGNIN OXIDATION PRODUCTS
Authors: Pepper J. M. , Siddiqueullah M.
Published: May 2006

A brief review is presented of the chemical nature and the methods of separation of those lignin derivatives obtained by the oxidation and/or alkaline hydrolysis of woody plants and isolated lignin or lignosulphonates. Nine such closely related derivatives, vanillin, syringaldehyde, p-hydroxybenzaldehyde, acetovanillone, acetosyringone, p-hydroxyacetophenone, vanillic acid, syringic acid, and p-hydroxybenzoic acid, were selected for a detailed study of their separation by cellulose column chromatography. Methods are presented whereby, by either a one- or two-stage process, a mixture of from any two to all nine of these compounds may be separated and the components recovered, using solvent systems which are suitable for subsequent quantitative spectrophotometric analysis. The application to a study of lignin chemistry is discussed.
PHOTOLYSIS OF AZOISOPROPANE
Authors: Riem R. H. , Kutschke K. O.
Published: May 2006

The photolysis of azoisopropane has been reinvestigated in an attempt to obtain a better understanding of the discrepancies found between the behavior of sec-propyl radicals produced from this source (1) and other sources under similar experimental conditions.Analytical difficulties encountered in an earlier investigation (1) were avoided through the extensive use of gas chromatography.It was found necessary to include an internal conversion reaction among the primary processes to explain the observed phenomena. A rough estimate of Einternal conversion − Edissociation = (1.99 ± 0.72) kcal/mole has been deduced. This is believed to be the first observation of Einternal conversion > Edissociation. An explanation of this observation remains a matter of conjecture though a tentative suggestion is offered.The data also leads to results in agreement with those found for other azo compounds and in agreement with the rates of reactions of sec-propyl radicals obtained from other sources under similar conditions.
REDUCTION OF MONOHALOGENATED NITROBENZENES WITH HYDRAZINE AND RANEY NICKEL. A CONVENIENT PREPARATION OF HALOGENATED ANILINES
Authors: Leggetter B. E. , Brown R. K.
Published: May 2006

The isomeric fluoro-, chloro-, bromo-, and iodo-nitrobenzenes can be converted to the corresponding halogenated anilines in good yield by refluxing methanolic hydrazine hydrate in the presence of Raney nickel.
THE POLYOXYPHENOLS OF WESTERN RED CEDAR (THUJA PLICATA DONN). II. DEGRADATION STUDIES ON PLICATIC ACID, A POSSIBLE LIGNAN ACID
Authors: Gardner J. A. F. , MacDonald B. F. , MacLean Harold
Published: May 2006

Plicatic acid, C20H22O10, a polyoxyphenol from western red cedar heartwood, described in a previous paper, has been further characterized by preparation and analysis of additional crystalline derivatives. Crystalline trimethyl and triethyl ethers have been oxidized by alkaline permanganate. The trimethyl ether yielded 3,4,5-trimethoxybenzioc acid, 4,5-di-methoxyphthalic acid (m-hemipinic acid), a pentamethoxy anthraquinone, and a pentamethoxy o-benzoylbenzoic acid which decarboxylated to 3,4,5,3′,4′-pentamethoxy benzophenone. Correspondingly, the triethyl ether gave 3,4-diethoxy-5-methoxybenzoic and 4-ethoxy-5-methoxyphthalic acids, a mixture of pentaalkoxy anthraquinones and a pentaalkoxy o-benzoylbenzoic acid which decarboxylated to 3,3′,4-triethoxy-4′,5-dimethoxy benzophenone identified by cleavage to 3-ethoxy-4-methoxybenzoic and 3,4-diethoxy-5-methoxy-benzoic acids. These results fix the positions of the two methoxyl, three phenolic hydroxyls, and mode of linkage of the two benzene rings. Further evidence is provided indicating plicatic acid is probably a lignan of the 4-aryltetrahydronaphthalene series.
PROTON MAGNETIC RESONANCE ABSORPTION IN ANHYDROUS SODIUM STEARATE
Authors: Grant R. F. , Dunell B. A.
Published: May 2006

The proton magnetic resonance absorption in anhydrous sodium stearate has been investigated over the temperature range −182 °C to 200 °C. An abrupt change in the line width and the second moment has been observed between 113 °C and 114 °C, which corresponds to a known phase transition. The results suggest that at temperatures below 114 °C the motion of the hydrocarbon-chain portion of the sodium stearate molecule is chiefly one of oscillation or rotation about the chain longitudinal axis. The hydrocarbon chains may be free to move about other axes at temperatures above 114 °C, although the molecule as a whole retains a fixed position in the crystal lattice.
THE LOCATION OF XANTHATE GROUPS IN PARTIALLY SUBSTITUTED STARCH XANTHATES
Authors: Adamek E. G. , Purves C. B.
Published: May 2006

The rate of xanthation of starch with carbon disulphide in 17.8% potassium hydroxide at 23° was followed by converting the potassium salts to the S-methyl xanthate esters, and analyzing the latter for sulphur. These esters were tritylated without changing the xanthate D.S., and unity minus the trityl D.S. was assumed to represent xanthate D.S. in the primary alcohol positions of the starch. About 62% of the xanthate groups occupied secondary positions after 100 minutes of xanthation, but after 3350 minutes about 58% of the surviving xanthate groups were primary.A sodium chlorite–pyridine–lactic acid mixture reduced the sulphur content of a fully acetylated starch S-methyl xanthate by about nine-tenths with little loss of acetyl groups, but the residual sulphur could not be eliminated and the resulting starch acetate could not be completely reacetylated or tosylated. The location of the hydroxyl groups in this acetate thus could not be studied by the tosylation–iodination method.
POTASSIUM DERIVATIVES OF FLUORENE AS INTERMEDIATES IN THE PREPARATION OF C9-SUBSTITUTED FLUORENES: II. COMPARATIVE REACTIVITIES OF THE ALKALI METALS, LITHIUM, SODIUM, AND POTASSIUM, WITH FLUORENE IN GLYCOL DIMETHYL ETHER, GLYCOL DIETHYL ETHER, TETRAHYDROFURAN, AND DIOXANE
Authors: Scherf G. W. H. , Brown R. K.
Published: May 2006

In the solvents 1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), tetrahydrofuran (THF), and dioxane, potassium reacts much more readily with fluorene than does sodium or lithium. Lithium is generally more reactive than is sodium. The order of effectiveness of the ethers is DME > DEE ≈ THF > dioxane. Although practically no reaction of these metals with fluorene occurs in toluene, the addition of small amounts of these ethers to toluene does accelerate such reaction. All three organometallic compounds are soluble in refluxing and cold (22°) DME, THF, and DEE except the 9-fluorenyllithium, which precipitates largely from cold DEE. The results are explained in terms of the relative electropositivities of the metals, their size, and the structure of the ethers. It is suggested that these ethers actually participate in the formation of the organometallic compound from the metal.Sodamide and lithium amide react as readily as or more readily than the metals with fluorene in DME to produce the organometallic compounds.Diphenylmethane and triphenylmethane react reasonably well with potassium in DME, but too slowly with lithium and sodium to be useful.
THE MECHANISM OF THE CARBONYL ELIMINATION REACTION OF BENZYL NITRATE KINETIC ISOTOPE EFFECTS AND DEUTERIUM EXCHANGE
Authors: Buncel Erwin , Bourns A. N.
Published: May 2006

The carbonyl elimination reaction (ECO2) of benzyl nitrate has been investigated with the object of distinguishing between the concerted and carbanion mechanisms. A deuterium exchange experiment resulted in a very small amount of deuterium pickup. The nitrogen isotope effect, k14/k15, associated with formation of the nitrite ion was found to be 1.0196 ± 0.0007 at 30 °C. The two results taken together exclude the formation of a carbanion intermediate but are consistent with a concerted mechanism.Benzyl-α-d2 nitrate has been prepared and the rate of its carbonyl elimination reaction compared with that of the undeuterated compound. The deuterium isotope effect was 5.04 ± 0.25 at 60 °C. The significance of the magnitude of the nitrogen and deuterium isotope effects and of their interrelationship with the Hammett reaction constant rho is discussed in terms of the nature of the transition state and a comparison is made with other E2 elimination reactions.
A METHOD FOR ADIABATIG COMPRESSION OF GASES UNDER CONTROLLED CONDITIONS
Authors: Graham G. D. , Maass O.
Published: May 2006

A preliminary account is given of an experimental technique by means of which the specific heats of gases may be measured at high temperatures and pressures. With the transducer employed consistent results were obtained up to 7000 p.s.i. and it is proposed to incorporate a transducer having a much higher pressure range where it is estimated that temperatures up to 10,000 °K can be recorded.
THE DONOR CHARACTERISTICS OF THE CARBONYL: GROUP:II. THE EFFECT OF ANGULAR VARIATIONS AT THE CARBONYL GROUP
Authors: Cook Denys
Published: May 2006

The effect of variations in the angle X—C—X′ (in a typical carbonyl compound XX′C=O) on the carbonyl stretching frequency (νc=o) is examined in the light of recently published empirical relations between νc=o and the ionization potential.
AN INFRARED STUDY OF THE ADSORPTION OF BUTENES ON SURFACES OF POROUS VYCOR GLASS
Authors: Little L. H. , Klauser H. E. , Amberg C. H.
Published: May 2006

The adsorption and reactions of the four butenes on porous Vycor glass at room temperature have been studied by infrared spectroscopy. Initial adsorption was rapid and was found to perturb the surface hydroxyl groups of the glass. In the case of the n-butenes rapid isomerization took place at room temperature. In addition to this the adsorbate spectra showed the occurrence of a slower reaction which led to an increase in saturated C—H groupings. C8 and higher compounds were shown to have formed; on outgassing at room temperature small amounts of cracking products were collected. The polymerization of isobutene was particularly rapid. Experiments at low coverage (θ ∼ 0.001–0.002) gave identical initial spectra for the n-butenes. These were discussed in terms of possible models for butene adsorption. A reduction in the alumina and zirconia content of the glass by acid leaching resulted in decreased rates of isomerization and polymerization, suggesting that one or both of these oxides are at least partially responsible for the activity of the glass. A pure silica aerogel was almost completely inactive. Quantitative measurements of the spectra of several monoolefins in solution were made for comparison with the surface species, in particular with respect to their molar intensities of absorption.
OXIDATION OF WHEAT STARCH WITH ALKALINE HYPOCHLORITE
Authors: Eisenbraun A. A. , Purves C. B.
Published: May 2006

The starch was oxidized with 5.5 base molar equivalents of 0.43 M calcium hypochlorite kept near pH 12 and 20°. The rate of oxidation was consistent with the occurrence of two first-order reactions differing in rate by a factor of 10, the more rapid of which consumed about 4 moles of hypochlorite for each C6H10O5unit actually oxidized. Oxalic acid (0.2 mole) and perhaps carbonic acid [Formula: see text] were formed directly, but it was necessary to hydrolyze the product in order to liberate D-glucose (0.4 mole), glyoxylic acid (0.03 mole), D-erythronic acid (0.11 mole), mesotartaric acid (0.02 mole), D-tartaric acid (0.02 mole), L-tartaric acid (0.01 mole), D-glucuronic acid (0.004 mole), and probably tartronic acid [Formula: see text].
PHOTOOXIDATION OF AZOMETHANE: IV. THE ROLE OF FORMALDEHYDE
Authors: Shahin M. , Kutschke K. O.
Published: May 2006

The photooxidation of azomethane has been reinvestigated over a range of conversion extending to at least 7% at relatively high oxygen pressure and at 162 °C. Kinetic and tracer (added C13H2O) studies support the view that the formaldehyde formed in the reaction can act as a source of the oxides of carbon. These were found to be enriched in C13 in the tracer work.
THE PREPARATION AND SOME PROPERTIES OF GERMANIUM DIFLUORIDE
Authors: Bartlett Neil , Yu K. C.
Published: May 2006

Germanium difluoride can be prepared by the reduction of germanium tetrafluoride with germanium metal. It is a white solid, m.p. 110°, and is orthorhombic, a = 8.30, b = 5.17, c = 4.67 Å. It possesses strong reducing properties.
OXIDATION OF MANGANATE BY HYPOCHLORITE
Authors: Lister M. W. , Yoshino Y.
Published: May 2006

The oxidation of potassium manganate to potassium permanganate by potassium hypochlorite has been examined. The rate of the reaction is proportional to the square of the manganate concentration and the first power of the hypochlorite, and it is inversely proportional to the permanganate concentration and to the square of the hydroxide ion concentration. It seems probable that the reaction involves the intermediate formation of hypomanganate ions from a relatively fast disproportionation of manganate, followed by a slower oxidation by hypochlorite. The following mechanism is tentatively proposed:[Formula: see text]Data on the over-all rate and effective activation energy (19.6 kcal/g-molecule) are given; but at present it is not possible to separate all the rate constants and equilibrium constants.
EXCEPTIONS TO HUDSON'S RULES OF ISOROTATION: THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF ANOMERIC PYRIMIDINE 2-DEOXY-D-RIBONUCLEOSIDES
Authors: Lemieux R. U. , Hoffer M.
Published: May 2006

Nuclear magnetic resonance spectroscopy and optical rotatory dispersion measurements were used to correlate the configurations of anomeric pairs for the 1-(2-deoxy-D-ribofuranosyl) derivatives of 5-methyl- and 5-fluoro-uracil. The optical rotations of the anomers were found opposite to those expected on the basis of Hudson's rules of isorotation.
SHEAR DEPENDENCE IN THE VISCOMETRY OF HIGH POLYMER SOLUTIONS: A NEW VARIABLE-SHEAR CAPILLARY VISCOMETER
Authors: Cragg L. H. , Oene H. Van
Published: May 2006

The principles of capillary viscometry are reviewed, and design criteria for capillary viscometers to be used with non-Newtonian liquids are discussed. A description is given of a new type of variable-shear capillary viscometer—a modification of the Ubbelohde suspended-level viscometer—designed for measurements in the low-shear range. The instrument is rugged, convenient, and precise, and makes possible measurements at free fall over a 10-fold range of shear stress (or shear rate), a range that can easily be extended by use of two or more suitably modified instruments or by the application of external pressure. Experimental evidence is presented to show that proper choice of the dimensions of the instrument eliminates or minimizes most of the "effects" that limit the precision of measurements of relative viscosity (and related functions) of high polymer solutions in the range of low shear stresses.
THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: V. THE ANALYSIS OF DECEPTIVELY SIMPLE SPECTRA
Authors: Abraham R. J. , Bernstein H. J.
Published: May 2006

The analyses of the ABX, A2X2, and ABXY types of spectra are discussed in detail under the conditions for which the observed spectra give less than the theoretical number of transitions. These conditions for which an observed spectrum is deceptively simple are derived from the general analyses, and experimental examples of such spectra are given.
STUDIES ON THE CRYSTALS SEPARATING FROM AQUEOUS LITHIUM NITRATE SOLUTION
Authors: Aravamudan G. , Ramaseshan S.
Published: May 2006

not available
THE FLUORINE MAGNETIC RESONANCE IN THE IONS [BF4]− AND [BF3CF3]−
Authors: Chambers R. D. , Clark H. C. , Reeves L. W. , Willis C. J.
Published: May 2006

not available
SYNTHESIS OF α-POLYOXYMETHYLENE-C13 AND α-POYOXYMETHYLENE-O18
Authors: Renaud R. N. , Leitch L. C.
Published: May 2006

not available
THE OXIDATION OF DI-tertiary-BUTYL PEROXIDE
Authors: Blake A. R. , Kutschke K. O.
Published: May 2006

The oxidation of di-t-butyl peroxide has been investigated in a static system at low conversion at 124 °C with sufficient oxygen present to suppress completely the formation of methane and ethane. The decomposition of the t-butoxy radical is unaffected by the presence of oxygen. A major product of the oxidation is formaldehyde whose yield rapidly approaches a stationary value. It is postulated that the major source of formaldehyde is the decomposition of methyl peroxy radicals, which may also abstract hydrogen from formaldehyde to form methyl hydroperoxide, and that this competition leads to the stationary concentration of formaldehyde actually observed. Methyl hydroperoxide was demonstrated to be unstable in the system and the predominant decomposition product was methanol, a compound also found in high yields in the oxidation. Experiments with added formaldehyde-C13 showed that formaldehyde can be converted to carbon monoxide in the system and indicated that formaldehyde was a likely precursor to the carbon monoxide found in the oxidation.
BOND LENGTHS AND BOND ANGLES IN OCTAHEDRAL, TRIGONAL- BIPYRAMIDAL, AND RELATED MOLECULES OF THE NON-TRANSITION ELEMENTS
Authors: Gillespie R. J.
Published: May 2006

The stereochemistry of molecules in which there are five or six pairs of electrons in the valency shell of a central atom is discussed in terms of the repulsions that exist between pairs of electrons in the valency shell as a consequence of the operation of the Pauli exclusion principle. An explanation is given for the difference in lengths of the axial and equatorial bonds in molecules such as PCl5 and ClF3 whose structures are based on the trigonal-bipyramidal arrangement of five valency-shell electron pairs. The fact that in molecules with a central atom with a valency shell of six electron pairs, one of which is a lone pair and which have the structure of a square pyramid, the central atom always lies below rather than in, or above, the base of the square pyramid, is also accounted for.
π-BONDING IN INORGANIC COMPOUNDS: II. THE TRANSMISSION OF ELECTRONIC EFFECTS THROUGH SQUARE-PLANAR COMPLEXES
Authors: Westland A. D. , Westland L.
Published: May 2006

Measurement of the transmission of electronic effects through square-planar complexes of platinum has provided evidence of double bonding to halogen and nitro ligands. The nuclear magnetic resonance chemical shift of the β-protons in pyridine ligands serves as an indicator of electron drift in the complexes. Justification is thus provided for the assumed mechanism of the trans effect involving π-bonding. The observations are in accord with the assumption that the increase in trans-directing powers with atomic number of the halogen is due to an increasing tendency to accept d-electrons from the central atom.
A KINETIC ISOTOPE EFFECT STUDY OF THE TSCHUGAEFF REACTION
Authors: Bader Richard F. W. , Bourns A. N.
Published: May 2006

Three different kinetic isotope effects have been measured in the thermal decomposition of S-methyl-trans-2-methyl-1-indanyl xanthate: the S32/S34 effect for the thio-ether sulphur atom, the S32/S34 effect for the thion sulphur, and the C12/C13 effect for the carbonyl carbon. The results of these measurements provide strong support for a two-step mechanism, in which the rate-determining step is the removal through a cyclic transition state of the cis beta hydrogen atom by the thion sulphur atom.
CONTRIBUTION À L'ÉTUDE DE LA RÉACTION DE VON RICHTER: III. SUR LA RÉACTION AVEC DIVERS NITRONAPHTALÈNES
Authors: Cullen E. , L'Écuyer Ph.
Published: May 2006

not available
PROTONATION OF THE AMIDE GROUP: II. DICYCLOHEXYLUREA-O18
Authors: Stewart Ross , Muenster L. J.
Published: May 2006

Dicyclohexylurea-O18 containing 78% oxygen-18 has been prepared. The amide I and II bands in this molecule are located at 1611 and 1575 cm−1 respectively compared to 1628 and 1575 cm−1 in ordinary dicyclohexylurea (KBr disk). Thus the amide I band (carbonyl stretching) undergoes the expected shift to lower frequency on isotopic substitution. The p-toluenesulphonate salt of dicyclohexylurea has been prepared and been found to have a band at 1669 cm−1 commonly attributed to carbonyl stretching in amide salts. This band, however, undergoes no isotopic shift and is clearly not due to a carbonyl stretching motion. This result casts doubt on the infrared evidence supporting N-protonation of amides.
STEROIDS: V. PYRIDINIUM BETAINES OF 2-α-BROMOCHOLESTAN-3-ONE
Authors: Frangatos G. , Taurins A.
Published: May 2006

2-α-Bromocholestan-3-one reacts with pyridine, and 3- and 4-methylpyridines to give the 1-[2-(3-oxocholestanyl)]pyridinium bromides which, on dehydrobromination with bases, form the betaines of 1-[2-(3-oxocholestanyl)]pyridinium hydroxides.
INFRARED SPECTRA – STRUCTURE CORRELATIONS OF N-SUBSTITUTED TRIFLUOROACETAMIDINES
Authors: Grivas John C. , Taurins Alfred
Published: May 2006

A correlation between the infrared spectra and the structure of some N-mono- and N-disubstituted trifluoroacetamidines is presented. It was found that there was a considerable similarity between the infrared spectra of trifiuoroacetamidines and those of the corresponding trichloroacetamidines. Additional information of the existence of these amidines in the imino form, CF3—C(=NH)NHR, was provided by the infrared study of N,N-dideuterioamidines.
THE EFFECT OF SOLVENT AND TEMPERATURE ON THE CIS–TRANS ISOMERISM OF ORTHO-tert-ALKYL PHENOLS
Authors: Ingold K. U. , Taylor D. R.
Published: May 2006

The effects of different solvents and of a change of temperature on the infrared band due to the fundamental hydroxyl stretching vibration in several 2,6-di-t-alkyl phenols and in the corresponding ortho-t-alkyl phenols have been examined. The conclusion that the two bands observed in ortho-t-alkyl phenols represent cis and trans isomers has been confirmed. The differences in enthalpy and entropy between the two isomers have been measured for six different phenols.
PHOTOCHEMICAL SYNTHESES: I. THE REACTION OF ALDEHYDES AND KETONES WITH CYCLOALKENES
Authors: Mayo P. de , Stothers J. B. , Templeton W.
Published: May 2006

The irradiation of dialkyl ketones in cyclohexene leads to the formation of cyclohexenyl-dialkylcarbinols. The use of aldehydes leads to the formation of the corresponding secondary alcohols, but the reaction is more complex because of concomitant Kharasch addition which can, however, be suppressed. The mechanism of the alcohol formation has been elucidated by the use of an optically active substrate, carvomenthene, and has been shown to involve the intermediacy of a cyclohexenyl radical. The structure and genesis of a biscarbinol by-product is discussed.
KINETICS AND THERMODYNAMICS OF THE CRYSTAL STRUCTURE TRANSFORMATION OF SPECTROSCOPICALLY PURE ANATASE TO RUTILE
Authors: Rao C. N. R.
Published: May 2006

The transformation of spectroscopically pure anatase to rutile was first investigated by Czanderna, Rao, and Honig. But it was not possible, then, to provide the mechanism on a molecular scale because of the lack of very accurate kinetic data. The kinetics and thermodynamics of the transformation have now been carefully investigated.
N.M.R. SPECTRA OF SOME α–β UNSATURATED ESTERS
Authors: Fraser Robert R. , McGreer Donald E.
Published: May 2006

The results of analysis of methyl citraconate and mesaconate, methyl cis- and trans-crotonate, and methyl cis- and trans-2-pentenoate are reported. A previously reported analysis of the crotonates by first-order perturbation theory gave significantly different values for the 1,3 coupling constants. The discrepancy in results, which is due to the importance of second-order effects, emphasizes the need for caution in applying the first-order method. From values of 1,3 coupling constants reported here and elsewhere it is concluded that there is no simple relation between the magnitude of 1,3 coupling constants and geometrical configuration of the interacting nuclei.
INFRARED SPECTRA OF GASES CHEMISORBED ON ZINC OXIDE: I. CO AND CO2
Authors: Taylor J. H. , Amberg C. H.
Published: May 2006

The infrared spectra of CO and CO2 adsorbed on zinc oxide have been observed in the region 2–9 µ. The results show that CO does not exist as such on the surface at 155 °C, but is immediately oxidized to CO2. There is no evidence for carbonate formation in the adsorption of CO, the spectra corresponding to structures of the carboxylate type. A band is observed at 2174 cm−1 for CO at 25 °C which may correspond to dipole interaction or to an oxidation step.
OXIDATION OF CHOLEST-4-EN-3-ONE WITH PERIODATE–PERMANGANATE
Authors: Edward J. T. , Holder D. , Lunn W. H. , Puskas I.
Published: May 2006

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ISOTOPE EFFECT IN HEAVY ION RANGE STUDIES
Authors: Davies J. A. , McIntyre J. D. , Sims G. A.
Published: May 2006

From measurements of the isotope ratio (Na22/Na24) at various depths of penetration, it has been possible to determine at 24 kev the small difference in the median ranges of the sodium isotopes. Na22 has the slightly larger median range, as is predicted by the Nielsen equation. Monte Carlo calculations show that an isotropic elastic-scattering model provides a reasonable explanation for the magnitude of the range difference and for the observed variation in the isotope ratio as a function of depth.
THE KINETIC ENERGY OF Cs136 PRIMARY FRAGMENTS FROM FISSION OF U235
Authors: Brown F. , Oliver B. H.
Published: May 2006

The ranges of Cs136, Cs137, and Ba140 fission fragments in aluminum have been measured using an anodizing technique to strip layers from the aluminum together with radiochemical methods to determine the fission products. The mean ranges are, in milligrams per square centimeter: Cs136, 2.64; Cs137, 2.91; and Ba140, 2.82. The range distributions were of near-Gaussian form with the following percentage full widths at half height; Cs136 17.7; Cs137, 17.0; and Ba140, 17.5. The range–energy relationship of Bohr, R = const. A1/2E1/2Z−2/3, was tested using the range data of Katcoff (7) and of Niday (2) together with the kinetic energy data of Milton and Fraser (15) and found to be accurate, within experimental error, over any limited range of fragment masses. Using this formula it then appears that the total kinetic energy in the fission mode leading to Cs136 is ∼21 Mev less than normal.
SEARCH FOR CORRELATIONS OF MOST PROBABLE NUCLEAR CHARGE ZP OF PRIMARY FISSION FRAGMENTS WITH COMPOSITION AND EXCITATION ENERGY
Authors: Coryell Charles D. , Kaplan Morton , Fink Richard D.
Published: May 2006

The repartition of nuclear charge in fission has a narrower dispersion than almost any other property connected with the fission process. To a crude approximation, the distribution of nuclear charge between light and heavy partners L and H leads to the most probable charges (Zp)L and (ZP)H displaced from the respective charges ZA of β-stability by the same amount for the two fragments (Glendenin rule of equal charge displacement ECD, 1946). The existence of shell offsets in the ZA vs. A function for different neutron- and proton-shell regions must be considered. All available data for thermal fission U235(nth,F) are examined critically. The data show sudden offset-like drifts (fine structure) that may well be associated with shell properties of the products before the "neck" has dissolved. It is shown that these data eliminate naive equal charge displacement ECD, also an older competitive prescription of constant charge ratio CCR for the products, and an empirical Russian prescription (Apalin etal., 1960). The data are also examined in the light of the postulate that fission gives minimum nuclear plus coulombic potential energy (Present 1947, Fong 1955, Swiatecki-Blann 1960), and it is shown that the present mass formulas give too much uncertainty three to four β-decays from stability to give a useful test, but that shell effects in masses must be retained. Data from charged-particle fission with energy deposit up to 40–50 Mev are in reasonable accord with the low-energy data on correcting for composition and neutron boil-off. It is concluded from experiment that ZP is a single-valued function of A, known to about ± 0.15 unit for low-energy fission and ± 0.25 unit for medium-energy fission, and that the fine structure very probably present is an indication of intrinsic nuclear chemistry.
THE ATTACHMENT OF INERT GASES TO POWDERS FOLLOWING (n,γ) EVENTS
Authors: Kelly Roger
Published: May 2006

It has been found that, when argon, krypton, and xenon are irradiated with neutrons in the presence of various powders, a portion of the inert-gas activity becomes "attached" to the powder. The attached activity was shown to be highly enriched, and to be distinguishable from adsorbed activity. Expressing the attachment in terms of the attachmentefficiency, A ≡ (inert-gas activity attached to target)/(total inert-gas activity), it was found that A was independent of irradiation time and neutron flux, and for fine powders was also independent of pressure between 0.7 and 700 mm. The use of a very coarse powder or no powder at all led to a decrease in A, on the basis of which it was estimated that the maximum distance from a surface that attached activity can originate is about 200 mean free paths. The following miscellaneous relations were observed to hold:[Formula: see text] (ii) AAr > AKr > AXe, (iii) Aoxide > Ametal (approximate). The results were in general consistent with a mechanism of attachment based on electrical attraction: inert-gas atoms first acquire a high charge due to vacancy cascades initiated by the conversion of capture gamma rays; they then wander about, and, upon approaching a solid surface, are accelerated electrically into it.
SEARCH FOR THE (n,t) REACTION AT 14 MEV IN SOME MEDIUM WEIGHT NUCLEI
Authors: Baerg A. P. , Bowes G. C.
Published: May 2006

The (n,t) reaction at 14.6 Mev has been observed to occur in S32 with a cross section of 4 ± 1 microbarns. Upper limits for the cross section of this reaction are also given for Ca40, Cr50, Fe54, and Zn64 and the results are discussed qualitatively in the light of recently reported (10) (n,He3) reactions.
A GAS-CHROMATOGRAPHIC APPARATUS FOR THE STUDY OF THE HOT-ATOM CHEMISTRY OF ORGANIC HALIDES
Authors: Silbert M. D. , Tomlinson R. H.
Published: May 2006

The construction of an easily assembled and inexpensive gas-chromatographic apparatus is described. This system has been designed to determine β-active materials. The operation of this instrument involves the use of a temperature program in order to resolve materials boiling over a wide range of temperature.
SCINTILLATION COUNTING WITH ORGANIC PHOSPHORS
Authors: Funt B. Lionel
Published: May 2006

Current techniques employed in scintillation detection of beta emitters are reviewed. Internal liquid scintillation counting, with a number of homogeneous mixed solvent systems, is described. Heterogeneous counting systems containing radioactive material in the dispersed phase include scintillating gels, thickened scintillators, and emulsions, and a number of methods embodying direct counting of active deposits on filter paper. Heterogeneous systems with the radioactive material in the continuous phase are described and include plastic capillary counters, plastic filaments, or organic crystals wetted with aqueous solutions.
THE STRUCTURE OF DI-tert-BUTYLNAPHTHALENESULPHONIC ACIDS
Authors: Menard Marcel , Mitchell Leonard , Komlossy Jacqueline , Wrigley Averil , Chubb Francis L.
Published: May 2006

Commercial sodium di-tert-butylnaphthalenesulphonate has been resolved into its isomers, which were shown to be sodium 2,6- and 2,7-di-tert-butylnaphthalene-4-sulphonates.
INFRARED SPECTRA OF XANTHATE COMPOUNDS: II. ASSIGNMENT OF VIBRATIONAL FREQUENCIES
Authors: Little L. H. , Poling G. W. , Leja J.
Published: May 2006

Discrepant interpretations regarding the frequency of the C=S stretching mode are reviewed and assignments of frequencies for the vibrational modes of the xanthate group, [Formula: see text] are presented.A band at 1020–1070 cm−1 is assigned to the C=S stretching mode. Bands at 1200 cm−1 and 1110–1140 cm−1 are ascribed to the stretching vibrations of the C—O—C linkage.The effects of the alkyl hydrocarbon chain length and of metal atoms (alkali metals, copper, and zinc) in displacing some of the frequencies are recorded.
ELECTRODE POTENTIALS OF THE URANIUM CHLORIDES IN FUSED ALKALI CHLORIDE SOLUTIONS
Authors: Flengas S. N.
Published: May 2006

Using a silver – silver chloride reference electrode, the electrode potentials of the system U, UCl3(KCl, NaCl) and the redox potentials of the system Pt, UCl3, UCl4(KCl, NaCl) were measured at various concentrations of the uranium chlorides and at temperatures between 650 and 850 °C.From the results, the electrode potential of the system U, UCl4(KCl, NaCl) was calculated. In addition, the activity coefficients and partial molal properties of dilute solutions of UCl3 and UCl4 in the equimolar mixture of potassium and sodium chlorides were calculated.
CARBOXYMETHYLMERCAPTO AND CARBOXYMETHYLSULPHONYL DERIVATIVES OF NITROIMIDAZOLE
Authors: Fisher M. H. , Nicholson W. H. , Stuart R. S.
Published: May 2006

Several carboxymethylmercapto and carboxymethylsulphonyl derivatives of nitroimidazole were prepared for biological testing. Reduction or reductive cyclization of these compounds was unsuccessful.
ENZYMIC HYDROLYSIS OF A GLUCOMANNAN FROM JACK PINE (PINUS BANKSIANA LAMB.)
Authors: Perila O. , Bishop C. T.
Published: May 2006

A crude glucomannan was isolated from jack pine holocellulose in 17% yield. Repeated delignification and copper complexing of this product provided a purified glucomannan (5% of the holocellulose) containing glucose, mannose, galactose, and xylose in a molar ratio of 10:25:1:1. This polysaccharide was hydrolyzed by a commercial hemicellulase preparation, the cleavage products being removed by continuous dialysis of the reaction mixture. The following oligosaccharides were isolated from the hydrolyzate and identified; yields are based on the glucomannan:[Formula: see text]
A COUNTER FOR MEASUREMENT OF TRITIUM EXCHANGE IN SOLIDS
Authors: Sepall O. , Lang A. R. G. , Mason S. G.
Published: May 2006

An apparatus for measuring the exchange of tritium (H3) between water vapor and solids such as cellulose has been developed which is simpler, less expensive, and more precise than an earlier model.Both the exchange reaction and the determination of sample tritium activity are performed in a windowless, proportional counter. The background activity in sorbed water on counter surfaces is measured independently of sample activity. Satisfactory reduction of the effect of the electrostatic charge on the sample upon counting rate is achieved by the geometry of the counter.
SYNTHESIS OF SYMMETRICAL AND UNSYMMETRICAL DIALKYLPHOSPHINOUS CHLORIDES
Authors: Ferron J. L.
Published: May 2006

A series of compounds with the generalized formula RR′PCl have been obtained by the metal (antimony or zinc) reduction of [RR′PCl2]+[AlCl4]−. The yields of symmetrical and unsymmetrical dialkylphosphinous chlorides obtained by this method are superior to those obtained in previous syntheses.
FRIEDEL–CRAFTS REARRANGEMENTS IN BRANCHED CONDENSED RING SYSTEMS: I OCTAMETHYLOCTAHYDROANTHRACENE
Authors: Barclay L. R. C. , Gray A. H. , Milligan C. E.
Published: May 2006

Treatment of 1,1,4,4,5,5,8,8-octamethyl-1,2,3,4,5,6,7,8-octahydroanthracene (C22H34, I) with aluminum chloride produced a new hydrocarbon (C22H32, II) containing a conjugated olefinic double bond. Hydrocarbon II was proved to be 1,1,5,5,8,8-hexamethyl-3-isopropyl-5,6,7,8-tetrahydrobenzindene by spectral data, by oxidative studies, and by a synthesis of its reduction product, 1,1,5,5,8,8-hexamethyl-3-isopropyl-5,6,7,8-tetrahydrobenzindane (III). A benzenonium ion mechanism is postulated to explain the 1,2-phenyl shift accompanied by dehydrogenation in the formation of II from I. The detection of hydrogen in the off gas of the rearrangement supports this mechanism. A similar benzenonium ion mechanism can be applied to elucidate the mechanism of isomerization of tertiary to secondary alkylbenzenes reported in the literature.
THE PROTON RESONANCE SPECTRA OF SOME SUBSTITUTED FURANS AND PYRROLES
Authors: Abraham R. J. , Bernstein H. J.
Published: May 2006

The proton magnetic resonance spectra of some substituted furans and pyrroles have been analyzed for spin coupling constants and chemical shifts.The relative insensitivity of the spin coupling constants to the nature of the substituent makes it possible to estimate their values in the parent molecules furan and pyrrole. The magnitude of the spin coupling constants is correlated with the angles made by the CH bonds with the CC bonds of the ring.The chemical shifts are interpreted in terms of an effect due to the electronegativity of the substituent together with the effect due to conjugation with the ring.
THE MECHANISM OF THE ALCOHOLYSIS OF ALIPHATIC NITRITES: I. ALCOHOLYSIS OF 1-METHYLHEPTYL NITRITE IN ALKALINE AND NEUTRAL SOLUTION
Authors: Allen A. D. , Schonbaum G. R.
Published: May 2006

A polarimetric study of the kinetics of the alcoholysis of 1-methylheptyl nitrite in alkaline solution has shown that the reaction rate is proportional to both the nitrite and alkoxide ion concentration. The asymmetric carbon center is not involved in the reaction. In strictly neutral solution no reaction occurs; the commonly observed "neutral" reaction is attributed to traces of acid formed in the decomposition of the nitrite ester. The mechanism of the reactions is discussed.
ARSENIDES OF THE TRANSITION METALS: IV. A NOTE ON THE PLATINUM METAL ARSENIDES
Authors: Heyding R. D. , Calvert L. D.
Published: May 2006

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SOLVATION EFFECTS AND RELATIVE RATES III. SALT EFFECTS IN THE SOLVOLYSIS OF exo-NORBORNYL BROMIDE
Authors: McMichael Kirk D. , Clement Robert A.
Published: May 2006

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THE CARBOHYDRATE–PROTEIN LINKAGE IN GLYCOPROTEINS: PART I. THE SYNTHESES OF SOME MODEL SUBSTITUTED AMIDES AND AN L-SERYL-D-GLUCOSAMINIDE
Authors: Jones J. K. N. , Perry M. B. , Shelton B. , Walton D. J.
Published: May 2006

The syntheses of N-L-seryl-D-glucosamine, N-glycyl-D-glucosamine, N-L-glutamyl-D-glucosamine, and 1-O-β-L-seryl-N-acetyl-D-glucosaminide are described. These D-glucosamine derivatives may result from the fragmentation of some glycoproteins. The chemical properties of these compounds indicate that N-peptides are relatively stable in acid solution but unstable in neutral and alkaline solution. The seryl glucosaminide is relatively stable in alkaline solution but is hydrolyzed by acid.
CONSTITUTION OF A 4-O-METHYLGLUCURONOXYLAN FROM THE WOOD OF TREMBLING ASPEN (POPULUS TREMULOIDES MICHX.)
Authors: Jones J. K. N. , Purves C. B. , Timell T. E.
Published: May 2006

A 4-O-methylglucuronoxylan has been isolated in almost quantitative yield from the wood of trembling aspen (Populustretmuloides Michx.) The hemicellulose was electrophoretically homogeneous and had a number-average degree of polymerization of 212. Partial hydrolysis gave D-xylose, galacturonic acid, 4-O-methylglucuronic acid, and 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated polysaccharide, which contained 108 xylose residues per average molecule, gave 2-O-methylxylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and methyl 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyluronic acid) -3-O-methyl-D-xylopyranoside in a mole ratio of 0.2:95:1:11. It is concluded that the hemicellulose contained a linear framework of approximately 200 (1 → 4)-linked β-D-xylopyranose residues and that, on the average, every ninth xylose unit carried a (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid residue directly attached to the xylan backbone. The polysaccharide is evidently similar to the 4-O-methylglucuron-oxylans occurring in the wood of all arborescent angiosperms so far investigated.
SOME NEW COMPONENTS OF ROYAL JELLY
Authors: Brown William H. , Felauer Ethel E. , Freure Robert J.
Published: May 2006

Two additional acids, 10-hydroxydecanoic and p-hydroxybenzoic, have been isolated from the ether-soluble fraction of royal jelly. A sterol, 24-methylenecholesterol, has been found in the ether-insoluble, methanol-soluble fraction of royal jelly.
LYCOPODIUM ALKALOIDS: PART IV. ALKALOIDS OF JAMAICAN LYCOPODIUM CLAVATUM LINN.
Authors: Burnell R. H. , Mootoo B. S.
Published: May 2006

Seven alkaloids have been isolated from L. clavatum Linn. collected in Jamaica, clavolonine C16H25NO2, fawcettiine C18H29NO3, base A (now named fawcettimine), lycopodine, dihydrolycopodine, and L.2 (acetyldihydrolycopodine). Fawcettimine is a secondary amine now shown to be C16H25NO2. The isolation of deacetylfawcettiine C16H27NO2 in quantity from a later extraction indicated that there was a seasonal variation in the alkaloid content of the plant. These bases differ from those obtained from L. clavatum of Canadian or European origin.
LIGHT ABSORPTION STUDIES: PART XVIII. THE ULTRAVIOLET ABSORPTION SPECTRA OF BROMOBENZENES
Authors: Forbes W. F.
Published: May 2006

The ultraviolet absorption spectra of bromobenzene in various solvents, and the spectra of a series of substituted bromobenzenes in cyclohexane solution, are reported. The B-band spectral data confirm the hypotheses postulated for the B-band spectra of chlorobenzenes in the previous part of this series of papers. That is, the bromine atom usually gives rise to greater steric effects than the chlorine atom and the apparent mesomeric interaction as judged from these spectra increases with the size of the halogen substituent.Both bromobenzene and chlorobenzene C-band intensities are unusually small, and this is assumed to account for the frequent C-band similarity between the spectrum of a mono-substituted benzene derivative PhX, where X = OH, OCH3, NH2, and the spectrum of the corresponding chloro- or bromo-substituted PhX derivative.
PREPARATION AND DEHYDRATION OF DI-(1-HYDROXYCYCLOALKYL)-ALKANES
Authors: Bailey A. S. , Diaper D. G. M. , Schwemin M. V. H.
Published: May 2006

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