bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INFRARED SPECTRA OF 4-SUBSTITUTED-THIOSEMICARBAZIDES AND DIAZOTIZATION PRODUCTS
Authors: Lieber Eugene , Rao C. N. R. , Pillai C. N. , Ramachandran J. , Hites Ralph D.
Published: May 2006

The infrared absorption spectra of 4-substituted-thiosemicarbazides, 5-(substituted)amino-1,2,3,4-thiatriazoles, and the corresponding isomeric tetrazolinethiones have been studied and structural assignments of importance to these systems made or suggested. Important conclusions drawn from the spectral data are: there is no suggestion of any thiol–thione tautomerism for the solid 4-substituted-thiosemicarbazides and that the thione structure predominates for these substances; that the so-called 5-thiol-tetrazoles also exist as thiones; and that the diazotization products of the 4-substituted-thiosemicarbazides yield 1,2,3,4,-thiatriazoles rather than the isomeric open chain thiocarbamyl azides. The C==S, —N—C==S, and cyclic —N—N==N— configurational assignments, which are of importance to the classes of compounds studied, are discussed.
THE INFRARED SPECTRA OF ORGANO-PHOSPHORUS COMPOUNDS: II. THE 1–2.6 μ REGION
Authors: McIvor R. A. , Hubley C. E. , Grant G. A. , Grey A. A.
Published: May 2006

The application of near infrared spectra to the study of phosphorus compounds has been investigated. It has been found that each type of radical gives a characteristic set of bands, which are not appreciably affected by changes in the molecule more than two atoms distant. Characteristic group frequencies are given for MeO, EtO, n-PrO, i-PrO, n-BuO, Me, Et, Me2N, Et2N, and i-Pr2N groups attached to phosphorus. Only the MeP bands are noticeably altered by the nature of the substitution on the phosphorus atom. Qualitative predictions of the spectra of compounds containing more than one type of C—H group may be made by summing the contributions of the components.
THE SEPARATION OF RHODIUM AND IRIDIUM BY ION EXCHANGE
Authors: Berman S. S. , McBryde W. A. E.
Published: May 2006

Separations of rhodium and iridium as chlorides by means of columns of the anion exchanger Amberlite IRA-400 are described. Iridium, is maintained in the quadripositive state by the addition of cerium(IV), the presence of which is necessary to counteract the reducing action of the resin. The marked difference in affinity toward the resin of Ir(IV) and Rh(III) makes the separation possible. Rhodium can easily be eluted from the resin by 2 M hydrochloric acid. Removal of all the iridium from the resin is accomplished in a Soxhlet extractor with 6 M hydrochloric acid. A number of less successful procedures for this separation are discussed.
HYDROGENOLYSIS OF CARBOHYDRATES: V. ISOMERIZATION OF METHYL β-L-ARABOPYRANOSIDE
Authors: Perlin A. S. , Von Rudloff E. , Tulloch A. P.
Published: May 2006

Treatment of methyl β-L-arabopyranoside under hydrogenolytic conditions with copper chromium oxide catalyst induces extensive isomerization. Products formed include glycosides of D-ribose, D-xylose, D-lyxose, and L-lyxose which together represent about an 80–90% conversion of starting material. Isolation of these compounds shows that carbons 2, 3, and 4 undergo isomerization, but no evidence has been obtained of anomerization. These findings possibly explain the formation of an optically inactive mixture of cis- and trans-tetrahydropyran-3,4-diol under slightly more drastic reaction conditions.
THE CHEMISTRY OF PEAT: II. THE TRITERPENES OF PEAT MOSS (SPHAGNUM)
Authors: Ives D. A. J. , O'Neill A. N.
Published: May 2006

By further chromatographic fractionation of the unsaponifiable matter from an extract of peat moss (Sphagnum) three crystalline triterpenes have been isolated. They have been identified as α-amyrin, taraxerone, and taraxerol by their physical and chemical properties.
THE EFFECT OF WATER REMOVAL ON THE CRYSTALLINITY OF CELLULOSE
Authors: Kouris M. , Ruck H. , Mason S. G.
Published: May 2006

The effect of various modes of drying upon the crystallinity of cellulose has been determined by X-ray diffraction.No change in the crystallinity index was observed when previously undried pure cellulose fibers from softwood were dried from water under a wide range of conditions, but a lower value was obtained when they were dried from benzene to which the fibers were accommodated by a series of solvent exchanges. Heat of wetting determinations on the same samples indicated changes in the accessibility with different drying methods. Qualitative variations in the degree of intrafiber bonding were also detected by a differential staining method. The X-ray measurements suggested that drying from water either produces no change in lateral order or that such changes are too small to be detectable by X-rays.The crystallinity of cellulose prepared by dry-milling whole fibers was studied. The crystallinity was substantially reduced in a Wiley mill and obliterated in a ball mill. X-Ray diffraction showed that wetting with water and then drying restored the crystallinity, while similar treatment with other liquids yielded less definite results. However, by following the destruction of the lattice with progressive periods of milling, it was concluded that alcohols reform this lattice to a limited extent depending, among other factors, upon the swelling capacity.
THE MASS SPECTRA OF THREE DEUTERATED BUTANOLS
Authors: McFadden W. H. , Lounsbury M. , Wahrhaftig A. L.
Published: May 2006

The mass spectra of 1,1-dideutero-l-butanol, 1,1,1,3,3-pentadeutero-2-butanol, and 1,1,1,2,3,3-hexadeutero-2-butanol have been obtained using 70-volt ionizing electrons. Comparison of the cracking patterns of the deuterated butanols with those of the undeuterated compounds confirms certain known features of the mass spectra of alcohols and reveals further information regarding the formation of several rearrangement ions. The strong tendency for alcohols to break at bonds beta to the hydroxyl group has been attributed to charge localization on the oxygen and this feature is used to explain the formation of many of the rearrangement ions. It is postulated that a hydrogen atom may be transferred to the electron-deficient oxygen and that the resulting structure distributes its excess energy and charge to give the activated complexes leading to the observed ions.
SPECTRE INFRAROUGE DE HF À L'ÉTAT CRISTALLIN
Authors: Giguère Paul A. , Zengin Numan
Published: May 2006

not available
THE INFRARED CARBONYL STRETCHING BANDS OF ACETOPHENONES SUBSTITUTED IN THE METHYL GROUP
Authors: Jones R. Norman , Spinner Ernest
Published: May 2006

Measurements have been made of the positions and intensities of the C==O stretching bands in the infrared spectra of compounds of the types C6H5—CO—CH2X, C6H5—CO—CHX2, and C6H5—CO—CX3 where X = —Cl, —Br, —I, —CN, —C6H5, and —OH. In most cases two bands are observed, and these are attributed to gauche and cis conformations associated with hindered rotation about the CO—CH2X and CO—CHX2 bonds. The relative positions and intensities of these bands are discussed in terms of the steric, electrical, and mass effects of the substituents.
THE POLARIZED FLUORESCENCE OF VERY THIN ANTHRACENE CRYSTALS
Authors: Ferguson J. , Schneider W. G.
Published: May 2006

The polarized fluorescence from anthracene sublimation flakes has been measured at 300°, 77°, and 4 °K. A recording spectrometer was used to measure accurately the relative intensity of the two crystal polarizations and also to determine changes in the spectrum between 77° and 4 °K. The polarization ratio (b/a) was found to decrease with increasing wavelength and measurements made at 77° and 4 °K. indicate that there is more than one emitting level and that these have different polarization properties. The fluorescence arises from regions of weak absorption in the crystal and it is suggested that these regions occur in the neighborhood of imperfections. In addition the polarized fluorescence excited from anthracene sublimation flakes containing traces of tetracene has been determined and changes were found in the transfer efficiency between 77° and 4 °K., again suggesting the presence of more than one emitting level. No depolarization of the tetracene fluorescence was observed at low temperatures.
NOTE ON THE RATE OF EVOLUTION OF HYDROGEN AT A MAGNESIUM ANODE
Authors: Greenblatt J. H.
Published: May 2006

Recent work on the mechanism of the anodic dissolution of magnesium is reviewed and additional data on the temperature dependence of the rate of hydrogen evolution at magnesium anodes during electrolysis is given. It is concluded that the results obtained and the literature on this subject are explained more logically by a kinetic mechanism involving initial solution of a univalent magnesium ion followed by subsequent reaction of this ion with water than by postulating self-corrosion with hydrogen evolved at local cathodes.
ANIONIC POLYMERIZATION OF α-METHYLSTYRENE: PART II. KINETICS
Authors: Worsfold D. J. , Bywater S.
Published: May 2006

Dilatometric measurements have been made of the reaction rates in the reversible equilibrium anionic polymerization of α-methylstyrene initiated by sodium naphthalene in tetra-hydrofuran solution, at temperatures of −10°, −40°, and −77°. The kinetic results and measurements made of the viscosity of the polymer conform with the mechanism of the reaction proposed by Szwarc et al., modified by the large degree of reversibility found with this monomer at these temperatures.
LYCOPODIUM ALKALOIDS:VII. THE REACTION OF ANNOTININE WITH PHENYL LITHIUM
Authors: Perry G. S. , MacLean David B. , Manske R. H. F.
Published: May 2006

Annotinine, C16H21O3N, reacted with phenyl lithium to yield diphenylannotinine, C28H33O3N, containing two hydroxyl functions. Oxidation of diphenylannotinine by the Oppenauer procedure yielded a monohydroxyketone, C28H31O3N, while oxidation with chromic acid yielded a dihydroxyketone, C28H31O4N. A mechanism for the formation of these compounds is discussed in relation to the chemistry of annotinine.
ON THE DECOMPOSITION FLAME OF OZONE AT HIGH PRESSURE
Authors: Sandri R.
Published: May 2006

not available
THE LIMITING CONDUCTANCE OF POTASSIUM IODATE AND OF IODATE ION AT 25.00 °C
Authors: Campbell A. N. , Bock E.
Published: May 2006

Measurements have been made of the equivalent conductance of solutions of potassium iodate, at 25.00 °C at concentrations ranging from 0.8 × 10−4 to 16 × 10−4 N. From this the limiting equivalent conductance of potassium iodate is found to be 114.41 mhos and that of iodate ion 40.91 mhos. The experimental technique is described. The ionic conductances of chlorate, bromate, and iodate ions are compared.
THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: IV. FOUR NUCLEI: AB3
Authors: Abraham R. J. , Pople J. A. , Bernstein H. J.
Published: May 2006

The proton magnetic resonance spectrum of methyl mercaptan has been analyzed on the basis of the nuclear grouping AB3. The spectrum calculated for [Formula: see text] agrees very well with that observed.
SECOND-ORDER UNIMOLECULAR KINETICS IN THE THERMAL DECOMPOSITION OF HYDROGEN PEROXIDE VAPOR
Authors: Forst W.
Published: May 2006

The thermal decomposition of hydrogen peroxide vapor has been reinvestigated by the static method as a function of initial pressure at pressures up to 22 mm Hg, and in the presence of inert gas (helium, oxygen, and water) up to 100 mm Hg. In each case the apparent first-order rate constant increased linearly with pressure. It is demonstrated that under the present experimental conditions the pyrolysis of hydrogen peroxide shows behavior typical of an elementary unimolecular reaction in its low-pressure, second-order region. The reaction was accompanied by a heterogeneous decomposition which in the presence of foreign gas became inhibited. Helium was used as inhibitor over the temperature range 430–470 °C, which permitted calculating the activation energy for activation with peroxide and with helium. The results can be satisfactorily accounted for by assuming a critical energy of 47–50 kcal and five effective classical oscillators for activation with peroxide and three with helium, provided deactivation occurs on every collision. Kinetic evidence against this assumption is briefly discussed.
SEPARATION OF CARBOHYDRATES ON COCOANUT CHARCOAL COLUMNS
Authors: Barth F. W. , Timell T. E.
Published: May 2006

not available
QUENCHING AND VIBRATIONAL-ENERGY TRANSFER OF EXCITED IODINE MOLECULES
Authors: Arnot C. , McDowell C. A.
Published: May 2006

not available
SOME THERMODYNAMIC CONSIDERATIONS OF THE EFFECTS OF STRESS ON METAL ELECTRODE POTENTIALS
Authors: Flood E. A.
Published: May 2006

It is shown that the change in thermodynamic potential of a solid when elastically strained by the application of the principal stresses px, py, and pz is given by the equation[Formula: see text]where v is the volume per unit mass and [Formula: see text] is the shear strain work done on unit mass of the solid, at T and (px + py + pz) constant, as the relative values of px, py, and pz vary, i.e., as the values of the principal stresses vary from their mean.
SUR LA SYNTHÈSE DE QUELQUES XANTHONES POLYSUBSTITUÈES
Authors: Constantin R. , L'Écuyer P.
Published: May 2006

La synthése de la 4,6,7-triméthoxy- et de la 1-méthyl-4,6,7-triméthoxy-9-xanthone a été réalisée en faisant agir un mélande d'anhydride acétique et d'acide sulfurique sur l'acide 6-(2′-méthoxy)- ou 6-(2′-methoxy-5′-méthylphénoxy)-vératrique. La préparation de ces deux acides a été effectuée en condensant le 6-bromovératrate de méthyle avec le guaїacolate ou l'isocréosolate de potassium en présence de cuivre. La 1-carboxy-4,6,7-triméthoxy-9-xanthone, un produit de dégradation de la cularine, a été obtenue en oxydant la 1-méthyl-4,6,7-triméthoxy-9-xanthone par l'acide chromique en solution dans l'acide éthanoique.
RADIATION CHEMISTRY OF SOLUTIONS: II DOSE-RATE, ENERGY, AND TEMPERATURE DEPENDENCE OF A LEUCO TRIARYLMETHANE DOSIMETER SOLUTION
Authors: Armstrong W. A. , Grant G. A.
Published: May 2006

The dose-rate, energy, and temperature dependence of the system l0−4 M 4,4′-(5-chloro-2-thenylidene)bis[N,N-dimethylaniline], l0−4 M ferrous ammonium sulphate, 0.1 M sodium chloride, and 7 × 10−3 M hydrochloric acid has been investigated. No energy dependence was observed in the range 0.16 to 2.0 Mev and no dose-rate dependence was observed in the range 4 to 230 rads/minute. However, with dose rates of 400 to 1200 rads/minute, postirradiation dye fading was observed. In the dosage range 0 to 1000 rads this fading is not extremely serious. The system is slightly temperature dependent at temperatures lower than 30 °C and markedly dependent at higher temperatures. Dye yields of samples irradiated at 30 °C were 10% higher than those of samples irradiated at 15° but 33% lower than those of samples irradiated at 45°.
STEREOCHEMISTRY OF REDUCTION OF KETONES BY COMPLEX METAL HYDRIDES
Authors: Wheeler Owen H. , Mateos José L.
Published: May 2006

The stereochemistry of the reduction of a number of cyclic ketones with complex metal hydrides has been determined. In the absence of any large steric effect in the ketones, the reduction is essentially stereospecific, giving the more stable alcohol.
THE SYSTEM: NICOTINE – METHYLETHYL KETONE – WATER
Authors: Campbell A. N. , Kartzmark E. M. , Falconer W. E.
Published: May 2006

The systems: nicotine–water and nicotine – methylethyl ketone were investigated by thermal analysis but the eutectic points were not obtained due to the extreme viscosity and consequent supercooling of solutions of high nicotine content.The densities, viscosities, and refractive indices were determined for the nicotine – methylethyl ketone – water system at 25.0 °C.The mutual solubilities of nicotine, methylethyl ketone, and water were determined over the entire temperature range. A ternary critical point was found at 67.3 °C, the critical composition being 27 weight per cent nicotine; 14 weight per cent methylethyl ketone.The methylethyl ketone – water and nicotine–water solubility curves were redetermined. The existing data for the former system were confirmed but the data for the classical system nicotine–water were found to be seriously in error at the higher critical solution temperature. Thus the lower critical solution temperature was found to be 61.5 °C, in good agreement with previous figures, but the upper critical solution temperature lies at 233.0 °C, some twenty degrees higher than had been obtained by previous workers; the corresponding critical compositions are 36% and 40% nicotine respectively.
REARRANGEMENT STUDIES WITH C14 VI. THE FRIEDEL–CRAFTS ALKYLATION OF BENZENE WITH ETHYL-β-C14 IODIDE
Authors: Lee C. C. , Hamblin M. C. , James Nadine
Published: May 2006

not available
KINETICS OF EXCITED MOLECULES: I. KETENE
Authors: Connelly B. T. , Porter Gerald B.
Published: May 2006

The primary quantum yield of ketene decomposition was studied as a function of pressure, temperature, and wavelength. The results show that excited vibronic states are formed which may be degraded before dissociation can occur. The ratio of the rate of collisional degradation to the rate of dissociation decreases from 164 liters/mole at 3340 Å to 16.8 liters/mole at 3130 Å.
THE SOLUBILITY OF URANIUM PEROXIDE IN ACIDIC AND BASIC MEDIA AT 25 °C
Authors: Gayer Karl H. , Thompson Lancelot C.
Published: May 2006

The solubility of uranium peroxide UO4•2H2O was measured in NaOH and HClO4 solutions. Possible reactions of UO4•XH2O in dilute HClO4 solutions and possible reaction of UO4•XH2O in dilute NaOH solutions are indicated along with the calculated constants. As might be expected, the several oxygens associated with the uranium atom appear to make the hydroxide more acidic than basic.
PHYSICOCHEMICAL STUDIES OF LIGNINSULPHONATES: III. PROPERTIES OF FRACTIONS PREPARED BY SUCCESSIVE SULPHONATION OF PERIODATE LIGNIN
Authors: Goring D. A. I. , Rezanowich A.
Published: May 2006

Periodate lignin was sulphonated in stages by a series of short bisulphite cooks. At each stage the soluble ligninsulphonate was removed and purified, and the residue was resulphonated. The 14 fractions thus obtained had constant methoxyl content and ultraviolet absorption coefficients. There was a gradual increase in the sulphur content as the integral reaction time increased, but 26% of the ligninsulphonate possessed a sulphur content of less than 3%. There was a marked increase in both the intrinsic viscosity and rate of solution with increase in reaction time. The mechanism of the sulphonation reaction is discussed in the light of these results.
PHOTOOXIDATION OF BUTENES BY NITROGEN DIOXIDE AT DIFFERENT WAVE LENGTHS
Authors: Sato S. , Cvetanović R. J.
Published: May 2006

Photooxidation of butenes by nitrogen dioxide at room temperature has been studied at three different wave lengths: 2288, 2537, and 3261 Å. In the case of butene-1 an abrupt change in the ratios of reaction products is observed between 2537 and 2288 Å: about three times as much α-butene oxide as n-butyraldehyde is formed at 2288 Å, while the amounts of these two compounds are almost equal at the longer wave lengths. This discontinuity is ascribed to a difference in the mechanism of reaction with olefinic double bonds of the first excited state, O(1D), and the ground state, O(3P), of oxygen atoms. Experimental evidence indicates that there is collisional quenching of O(1D) to O(3P) atoms.Reactions of cis- and trans-butene-2 and of isobutene are much less reproducible, particularly so that of isobutene, because of the much more readily occurring thermal reaction of the excess nitrogen dioxide present with the epoxides initially formed.
THE ADSORPTION OF KRYPTON ON GRAPHITE ABOVE AND BELOW THE TRIPLE POINT
Authors: McDermot H. L. , Lawton B. E.
Published: May 2006

The adsorption of krypton on graphite has been measured above and below its Triple Point. Above the Triple Point, a smooth isotherm was found which showed two types of hysteresis. In contrast, the isotherm measured below the Triple Point displayed two discontinuities. The surface area of this graphite measured by means of the krypton isotherm was found to be in agreement with that previously measured by nitrogen adsorption.
THE KINETICS OF THE DECAY OF NITROGEN ATOMS AS DETERMINED FROM CHEMICAL MEASUREMENTS OF ATOM CONCENTRATIONS AS A FUNCTION OF PRESSURE
Authors: Kelly Roger , Winkler C. A.
Published: May 2006

A method is described for studying both the surface and homogeneous decay of N atoms in which the atom concentration reaching a reaction vessel after a period of decay is measured as a function of pressure by HCN production from ethylene or ethane under conditions of complete consumption of the atoms and complete initial dissociation of the nitrogen. The results indicated that the surface decay proceeded by a first-order mechanism between 55 °C and 400 °C, with the collision efficiency for an Na2HPO4 surface essentially constant at 2.75 × 10−4. The activation energy of surface decay was 1.0 kcal mole−1 and the concentration of surface species 1.9 × 1014 cm−2. It was concluded that the surface decay probably leads directly to molecules in the ground state.Depending on the temperature and whether or not N2 and N were considered equivalent as third bodies, the rate constant of the homogeneous decay varied from 1.09 × 10−33 to 13.2 × 10−33 cc2 molecule−2 sec−1. The homogeneous decay therefore appears to have a positive temperature coefficient and to be of only secondary importance below about 2 mm pressure under the prevailing conditions. The similarity of one-half the rate constant of homogeneous decay at 25 °C (0.55 × 10−33 to 0.97 × 10−33) to the rate constant of afterglow emission obtained by Berkowitz etal. (2 × 10−33) suggests that all homogeneous decay gives rise to afterglow via the 5Σ state.
THE HEAT AND ENTROPY OF ASSOCIATION OF THE COMPLEX IONS FORMED BY EDTA WITH THE LANTHANIDE ELEMENTS IN AQUEOUS SOLUTION
Authors: Betts R. H. , Dahlinger Olive F.
Published: May 2006

A radio tracer method has been used to measure the heat and entropy of association of all the lanthanide ions (except promethium) with the chelating agent EDTA. Entropy terms are largely responsible for the remarkable stability of these complex ions. The results suggest, but do not prove, that a change in configuration of the complex occurs after gadolinium (element 64).
ON THE MECHANISM OF ELECTROLYTIC DEPOSITION AND DISSOLUTION OF SILVER
Authors: Mehl Wolfgang , Bockris John O'M.
Published: May 2006

not available
CATHODIC POLARIZATION OF SILVER IN SULPHURIC ACID
Authors: Antoniou A. A. , Wetmore F. E. W.
Published: May 2006

The hydrogen overpotential on fine silver cathodes has been determined from 2 to 35° and over a current density range from 0.03 to 2000 μa cm−2. Two Tafel slopes were observed, RT/F at low currents, 2RT/F at high currents. The stoichiometric number was found to be one and the symmetry factor one-half at low currents. The heat of activation changed from 18.8 kcal at low currents to 14.3 at high currents.
THE ADSORPTION OF METHYLENE BLUE ON A POSITIVELY CHARGED MERCURY SURFACE
Authors: Los J. M. , Tompkins C. K.
Published: May 2006

Direct measurement of the surface concentration Г of methylene blue, adsorbed from a phosphate buffer solution onto an ideally polarized mercury electrode, has produced a Lang-muir-type isotherm. The maximum value of Г, Гm, was found to be dependent on the potential applied (E). Surface tension measurements showed that the rate-controlling process is not diffusion, but, presumably, the exchange of methylene blue cation (MB+) with phosphate ions. A model for this process has been proposed. This allowed the calculation of the rate constant of adsorption (ka) from the surface tension values as a function of time (ka ~ 5 × 10−5 cm/sec; dka/dE ~ 30 × 10−5). There is some evidence for the occurrence of a consecutive process, most likely the combination of adsorbed MB+ to dimers.
FREE RADICALS BY MASS SPECTROMETRY: XV. THE: MERCURY-PHOTOSENSITIZED DECOMPOSITION OF FORMIC ACID, ACETIC ACID, AND METHYL FORMATE
Authors: Kebarle P. , Lossing F. P.
Published: May 2006

The Hg(3P1) photosensitized decomposition of formic acid proceeds by two intramolecular rearrangement reactions, leading respectively to H2O and CO, and to H2 and CO2. No free radicals are produced. The decomposition reactions of methyl formate and of acetic acid proceed predominantly by the formation of free radicals, but intramolecular rearrangements also occur to a significant extent. For both these latter compounds the evidence suggests the occurrence of two modes of dissociation into free radicals:[Formula: see text]No evidence for the alternative mode of dissociation[Formula: see text]was found.
DÉRIVÉS DU TRIMÉTHYL-1,8,8 BICYCLO[3,2,1]OCTANE: V. RÉDUCTIONS CATALYTIQUE ET CHIMIQUE DE LA TRIMÉTHYL-1,8,8 BICYCLO[3,2,1]OCTANEDIONE-2,4
Authors: Favre H. , Richer J-C.
Published: May 2006

not available
THE DETERMINATION OF ATOMIC RATIOS IN THE URANIUM–OXYGEN SYSTEM BY A THERMOGRAVIMETRIC METHOD
Authors: Stonhill L. G.
Published: May 2006

A description is given of a thermogravimetric oxidation–reduction method for determining U–O ratios, especially suited to oxygen-sensitive materials of undetermined purity, and equally applicable to pure stoichiometric and non-stoichiometric oxides and their mixtures with each other and with uranium metal.Provided that no uncombined base metals other than uranium, and no oxidizable or reducible matter other than its oxides, are present, it is not essential to know the detailed composition of the sample, since the assay is based on interconversion of the stoichiometric oxides UO2 and U3O8 within that sample.Incidental advantages of this method are: the avoidance of manipulation of the sample during the determination, precise reaction control, and immediate recording of the completion or otherwise of the required reaction.
ON THE CONSTITUTION OF 2-KETO-L-GULONIC ACID
Authors: Gaspar N. J. , Los J. M.
Published: May 2006

not available
A MASS SPECTROMETER WITH A LOW-TEMPERATURE IONIZATION CHAMBER TO STUDY HETEROGENEOUS REACTIONS OF ATOMS AND FREE RADICALS: EXAMPLE, IODINE ATOMS
Authors: Blanchard L. P. , Goff P. Le
Published: May 2006

The main features of a mass spectrometer in which the ionization chamber can be cooled in a controlled way to the temperature of liquid nitrogen are given. Atoms or free radicals, formed in a heterogeneous quartz reactor that can be heated to 1000 °C, effuse through a small hole in the wall of this reactor and enter directly into the ionization chamber. With this instrument it is possible to study the various ways in which unstable particles disappear during collisions on a metallic surface maintained at low and controlled temperatures.The collision efficiency "b" of iodine atoms to form iodine molecules was found to vary between 1.7 × 10−3 and 4 × 10−3 on a surface at a temperature between +40 °C and −25 °C. Between−25 °C and −60 °C, the atoms are condensed at the same time as the iodine molecules; at lower temperatures, they are more "volatile" than iodine molecules, most of them colliding on the molecules of condensed iodine without reacting.
THE METAL-CATALYZED DECOMPOSITION OF NITROUS OXIDE (I). DECOMPOSITION ON PURE SILVER, SILVER–GOLD, AND SILVER–CALCIUM ALLOYS
Authors: Hayes Kenneth E.
Published: May 2006

The decomposition of nitrous oxide on silver, a silver–1.14% gold alloy, and a series of silver–calcium alloys has been studied. On all of these catalysts the initialrate of decomposition is proportional to the nitrous oxide pressure. The activation energy for pure metals, including platinum and gold, is proportional to the work function. For the silver–calcium alloys the activation energy falls rapidly with increasing calcium content, suggesting that the work function of these alloys falls with increasing calcium content.
THE ADSORPTION OF SULPHUR DIOXIDE BY GRAPHITE
Authors: McDermot H. L. , Lawton B. E.
Published: May 2006

not available
THE ELECTRONIC STATES OF CIS- AND TRANS-ACETYLENE
Authors: Howard H. , King G. W.
Published: May 2006

The electronic energy levels of cis- and trans-bent planar centrosymmetric acetylene molecules, with [Formula: see text] and r cc = 1.383 Å, have been calculated by the LCAO/ASMO/CI procedure. The lowest energy state that can spectroscopically combine with the linear ground state is found to be of symmetry class Au belonging to the trans-bent molecule and to lie at 4.58 ev above the ground state. This compares favorably with the experimentally observed electronic transition of lowest energy which is of type (1Au−1∑g+) and at 5.24 ev. The lowest-energy allowed transition to a cis-bent state of these dimensions is at 9.39 ev, and hence this may not form part of the unanalyzed system of bands in the 2000–1500 Å region, as has been suggested. However, a transition to a trans-bent state of type (1Bu−1∑g+) is predicted to fall in this region. The energies of other electronic states are discussed in relation to the observed absorption systems of acetylene.
EFFECT OF PRESSURE ON THE SPONTANEOUS AND THE BASE-CATALYZED HYDROLYSES OF EPOXIDES
Authors: Koskikalio J. , Whalley E.
Published: May 2006

The effect of pressures up to 3000 atm on the spontaneous and the base-catalyzed hydrolyses of ethylene and propylene oxides has been determined. It is that expected from the accepted mechanisms. The volumes of activation of ion–molecule reactions that probably occur without major change in polarity are reviewed. For all reactions that have been studied so far in which a C–O bond is formed the volumes of activation are about −5 to −10 cm3 mole−1.
PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: IV. THE HYDROLYSIS OF DIETHYL ETHER
Authors: Koskikallio J. , Whalley E.
Published: May 2006

The acid-catalyzed hydrolysis of diethyl ether has been measured in the temperature range 120–160 °C at low acid concentrations; the entropy of activation is −9.0 ± ~2.5 cal deg−1 mole−1. The effect of pressures up to 3000 atm has been measured at 161.2 °C; the volume of activation at 1 atm is −8.5 ± ~2 cm3 mole−1. These two results show that the slow step is bimolecular. The rate in concentrated acids was measured at 119 °C; the rate was much more nearly proportional to the acidity function h0 than to concentration of acid. This is contrary to the predictions of the Zucker–Hammett hypothesis, which is therefore not valid for the hydrolysis of diethyl ether.
A CRYSTALLINE DERIVATIVE OF 2-O-(4-O-METHYL-α-D-GLUCOPYRANOSYLURONIC ACID)-D-XYLOPYRANOSE
Authors: Timell T. E.
Published: May 2006

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A GAS CHROMATOGRAPHIC STUDY OF THE ADSORPTIVE PROPERTIES OF A SERIES OF ACTIVATED CHARCOALS
Authors: Habgood Henry W. , Hanlan James F.
Published: May 2006

From measurements of the gas chromatographic retention volumes, the initial slopes of the adsorption isotherms of nitrogen and the simpler hydrocarbons on a series of steam-activated coconut charcoals were determined. The initial heats of adsorption were obtained in the usual way from the temperature dependence. It was found for all gases that both the initial slope of the isotherm and the initial heat of adsorption decreased with increasing degree of activation of the charcoal (i.e. with increasing surface area per g). This suggests that the higher affinity for the very small pores in less activated material more than counterbalances the lower total surface.Measurements at several different carrier gas flow rates of the relative band width for the charcoals of least and of greatest activation demonstrated, as might be expected, a greater resistance to mass transfer for the former. However, the apparent diffusion coefficients calculated on the assumption that all transport is by gas phase in the pores were nearly the same for each charcoal and showed relatively little variation among the different gases.
INFRARED SPECTRA OF ORGANO-PHOSPHORUS COMPOUNDS: III. PHOSPHORAMIDATES, PHOSPHORAMIDOTHIONATES, AND RELATED COMPOUNDS
Authors: McIvor R. A. , Hubley C. E.
Published: May 2006

Examination of a number of new phosphorus compounds has provided additional confirmation for many of the group frequencies reported previously. In certain cases additional information has been obtained on the effect of environment on the band positions, and some previously unassigned bands have been attributed to specific structures. In particular, bands previously assigned to P(S), P(S)X, C—H deformation, P—O—(C), P—C, P—S—H, P—S(P), P—N, C—S(P), and C—N(P) are discussed.
ON THE COUPLING BETWEEN F19 AND H1 NUCLEI IN p-FLUOROTOLUENE
Authors: Schaefer T.
Published: May 2006

The proton and fluorine high resolution nuclear magnetic resonance spectra of p-fluorotoluene are discussed in terms of the case A2A2′X. The 4 × 4 submatrices are diagonalized in analytical form and therefore explicit values for all energy levels can be obtained. The spectra are consistent with [Formula: see text] which may be of theoretical interest.
ISOTHERMS OF BROMINE ON GRAPHITE
Authors: Hooley J. G.
Published: May 2006

The isotherms of bromine on eight carbon blacks and on natural graphite have been related to the known structures of these materials. The surface areas can be calculated from the adsorption isotherms and the size of the graphite crystals can be estimated from the extent of hysteresis on desorption. The isosteric heats of adsorption on the surface and between the layers are each 11 kcal mole−1. The formation of residue compounds displaces the isotherms equally at all pressures.
STERIC INHIBITION OF RESONANCE: III. CALCULATION OF RESONANCE ENERGIES AND BOND LENGTHS
Authors: Trotter James
Published: May 2006

In many aromatic nitro compounds steric effects prevent the attainment of complete coplanarity and inhibit resonance interaction between the nitro group and the aromatic π-electrons. The variations with nitro group tilt of resonance energy, electron distribution, and π-bond order in this type of molecule have been calculated by molecular orbital methods, and the corresponding bond length variations have been deduced. The calculated bond lengths for 9,10-dinitroanthracene and 9-nitroanthracene are compared with those measured by X-ray analyses.
THE KINETICS OF HYDROGEN CHEMISORPTION ON AN IRIDIUM CATALYST
Authors: Low Manfred J. D. , Taylor H. Austin
Published: May 2006

The kinetics of the chemisorption of hydrogen on an iridium catalyst have been studied at various temperatures and pressures. The rate of adsorption is well defined by the Elovich equation. Isothermal anomalies have been observed and were found to be a function of temperature and initial gas pressure.
THE EFFECT OF MOLECULAR OXYGEN ON THE REACTION OF OXYGEN ATOMS WITH cis-2-PENTENE
Authors: Sato S. , Cvetanović R. J.
Published: May 2006

The effect of the presence of nitrogen, oxygen, and nitric oxide on the reaction between cis-2-pentene and oxygen atoms has been investigated at room temperature (25 ± 2 °C). For production of oxygen atoms use was made of mercury-photosensitized decomposition of nitrous oxide and of the photolysis of nitrogen dioxide at 3660 Å.In the N2O work, the presence of molecular oxygen induced the formation of acetaldehyde, propanal, methanol, and ethanol. In the NO2 work, the amounts of acetaldehyde, propanal, and ethyl nitrate formed increased rapidly with increasing pressure of molecular oxygen. Possible reaction mechanisms for the formation of these compounds are discussed.Additional information was obtained on the pressure-independent fragmentation in the reaction of oxygen atoms with cis-2-pentene.
THE ACETOLYSIS OF SOME HYDROXYTETRAHYDRO-2-PYRANS
Authors: Francis Thomas , Rudloff E. Von
Published: May 2006

The reaction between acetic anhydride and several hydroxytetrahydropyrans in the presence of boron trifluoride has been studied. 2-Methyl-3-hydroxytetrahydropyran, 2-hydroxymethyl-4,5-dihydroxytetrahydropyran, and 3,4-dihydroxytetrahydropyran all underwent normal acetolysis to the expected straight-chain polyol acetates. Optically active forms of cis-and trans-3,4-dihydroxytetrahydropyran gave the same, inactive pentanetetrol, showing that racemization of the active centers had accompanied ring cleavage. 2-Hydroxymethyl-tetrahydropyran gave 1,3,6-hexanetriol besides the expected 1,2,6-isomer. The reagent did not cleave 4-hydroxytetrahydropyran nor dihydro-D-galactal, but the latter underwent hydroxyl inversion to give dihydro-D-altral. 1,5-Anhydro-D-sorbitol (polygalitol) appeared to undergo both ring fission and inversion.
SZILARD CHALMERS REACTION IN POTASSIUM MANGANATE
Authors: Mackenzie R. A. , McCallum K. J.
Published: May 2006

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THE ADDITION OF ETHYL RADICALS TO ETHYLENE
Authors: Lampe F. W. , Field F. H.
Published: May 2006

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STRUCTURE AND REACTIVITY OF C3H3 RADICAL
Authors: Giacometti G.
Published: May 2006

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A MANNAN PRODUCED BY BACILLUS POLYMYXA
Authors: Ball D. H. , Adams G. A.
Published: May 2006

During the fermentation of glucose, sucrose, or lactose by Bacilluspolymyxa, a mixture of polysaccharides is formed, one of which has been isolated by mild procedures and shown to contain mannose as the only sugar together with approximately 13% protein. Acid hydrolysis of the methylated mannan gave 2,3,4,6-tetra-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4,6-tri-O-methyl-D-mannose, and 3,4-di-O-methyl-D-mannose in the approximate ratio 2:1:1:2. Periodate oxidation results are in agreement with the methylation data and indicate a molecular weight of approximately 3000.
IONIZATION POTENTIALS OF METHYLAMINES AND ETHYLAMINES BY ELECTRON IMPACT
Authors: Collin Jacques
Published: May 2006

Recent determinations of the ionization potentials of methylamines and ethylamines obtained by electron impact have been compared with photoionization results and discussed in relation to the Franck–Condon principle. It seems that the observed discrepancies are mainly due to differences in the sensitivities of the detecting devices.
ISOTOPIC AND HOT RADICAL EFFECTS IN THE REACTION OF HYDROGEN ATOMS WITH ETHYLENE
Authors: Turner A. H. , Cvetanović R. J.
Published: May 2006

Reactions of D atoms with C2H4, H atoms with C2D4, and H atoms with C2H4, at room temperature are compared. Pronounced differences in the extent of isotopic exchange have been found. The observed isotopic and pressure effects provide evidence for the importance of "hot" ethyl radicals in these reactions and their responsibility for isotopic exchange. The atoms are generated by the mercury-photosensitized decomposition of hydrogen and deuterium and their concentration is sufficiently small so that "atomic cracking" does not occur.
THE X-RAY STRUCTURE ANALYSIS OF DEMETHANOL ACONINONE HYDRIODIDE TRIHYDRATE
Authors: Przybylska Maria , Marion Léo
Published: May 2006

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A SIMPLE THERMOSTATED PROBE ASSEMBLY FOR HIGH RESOLUTION NUCLEAR MAGNETIC RESONANCE SPECTRA
Authors: Brownstein S.
Published: May 2006

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ACTIVATION ENERGIES OF SEMICONDUCTORS WITH THE ZINC BLENDE STRUCTURE
Authors: Pearson W. B.
Published: May 2006

Difficulties of determining the binding energies and effective charges on the atoms are the main reason why no systematic explanation of the variation of the size of the energy gap among members of the simplest family of semiconductors—those with the zinc blende structure—has ever been given. It is shown that by the choice of suitable atomic parameters for discussing the activation energies of these compounds these difficulties may be avoided, and the variation of the size of the energy gap between one compound and another can be systematically accounted for. In the treatment which develops no particular distinction need be made between the III–V, II–VI, and I–VII compounds, and it is concluded that the anomalously high or low activation energies, which certain compounds appear to have, are just the result of the relative sizes of the cations and anions in influencing the polarization of the bonds.
RADIATION-INDUCED ADDITION OF HBr TO C2H4 IN THE GASEOUS STATE
Authors: Armstrong D. A. , Spinks J. W. T.
Published: May 2006

The gas phase addition of hydrogen bromide to ethylene in a pyrex irradiation cell was induced by the action of Co60 γ-rays. Dose rates were calculated by means of the Bragg–Gray cavity principle from saturation ionization currents measured in air in a similar cell. The only product detected was ethyl bromide and the ion pair yield was of the order of 105. The rate of addition was followed with an electrically adjusted "spoon gauge" and was studied (a) with HBr in great excess, (b) with HBr and C2H4 in equal concentration, (c) with C2H4 in great excess. For condition (a) the rate showed a first-order dependence on [C2H4], an approximate second-order dependence on [HBr], a negative temperature coefficient, and a dose rate exponent of unity. It was concluded that the reaction rate was determined by the same step as for the photobromination reaction and that wall termination predominated. For conditions (b) and (c) the dose rate exponent was found to be approximately 0.5 indicating a predominance of mutual termination. Definite conclusions with regard to the termination reaction were not possible but the data suggested that certain ion–molecule reactions may precede ion combinations.
THE REACTION OF NITROACETONITRILE WITH AROMATIC AMINES
Authors: Grivas John C. , Taurins Alfred
Published: May 2006

It has been shown by infrared spectroscopic study that the alleged N-aryl-nitroacetamidines are in fact the salts of nitroacetonitrile with aromatic amines.
KINETICS OF THE INHIBITION OF α-CHYMOTRYPSIN BY METHANOL AND DFP
Authors: Stein Bernard R. , Laidler Keith J.
Published: May 2006

A study has been made of the kinetics of the α-chymotrypsin-catalyzed hydrolysis of methyl hydrocinnamate in the presence of various concentrations of methanol, of eserine, and of diisopropyl phosphorofluoridate (DFP). In 20% methanol the pH optimum, using a substrate concentration of 1.20 × 10−3M, is 7.8; in pure water it is 8.3; and at intermediate pH's the optimum varies between these values. No inhibition was observed with eserine. In aqueous solution the character of the inhibition by DFP differs from that in alcohol solutions; the inhibition is of the competitive type, and the inhibition constant varies with pH in essentially the same manner as does the rate of the reaction. This result suggests that DFP interacts with the same active groups on the enzyme as are responsible for the hydrolysis of the substrate. A specific mechanism for inhibition is suggested.
NOTE ON THE DETECTION OF AN APPARENT PHASE TRANSITION OF ADSORBED WATER ON POROUS VYCOR GLASS BY MEASUREMENTS OF DIMENSIONAL CHANGES
Authors: Hodgson C. , McIntosh R.
Published: May 2006

A new technique is described for detecting possible phase transitions of adsorbates. The method involves the measurement of length changes of the solid, but only solids for which the surface-to-volume ratio is large could be used with the present form of instrument because of its moderate sensitivity. Using this measurement an apparent phase transition for water adsorbed on porous Vycor glass has been detected at approximately −22 °C.
ULTRAVIOLET IRRADIATION OF PYRIMIDINE DERIVATIVES: III. INFLUENCE OF HYDROGEN CYANIDE ON THE PHOTOLYSIS
Authors: Moore A. M.
Published: May 2006

The presence of HCN in concentrations up to 0.05 M in aqueous, buffered solutions of uracil, uridine, and 1,3-dimethyluracil has been shown to divert the normal course of the photochemical hydration reactions of these compounds as a result of photochemically induced combination between HCN and the pyrimidine derivative. A simple calculation indicates that HCN is more efficient than water in reacting with activated uracil molecules by a factor of about 103. The possible general significance of such nucleophilic addition reactions in the photochemistry of nucleic acids is discussed.
LIGHT ABSORPTION STUDIES: PART XV. THE ULTRAVIOLET ABSORPTION SPECTRA OF ANISOLES
Authors: Dearden J. C. , Forbes W. F.
Published: May 2006

Anisoles, compared with phenols, possess similar spectral properties, except that properties determined mainly by the hydrogen atom of the hydroxy group are modified. In this way, comparison of the ultraviolet absorption spectra of phenols and anisoles permits, for example, the study of the spectral effects of hydrogen bonding and the study of steric interactions involving the hydroxy and methoxy groups.
PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: V. THE HYDROLYSIS OF ACETIC ANHYDRIDE
Authors: Koskikallio J. , Pouli D. , Whalley E.
Published: May 2006

The spontaneous and the acid-catalyzed hydrolyses of acetic anhydride have been measured as a function of temperature over the range 0 to 40 °C, as a function of pressure over the range 0 to 3 kb at 0 °C, and as a function of solvent over the range 0 to 70.3% w/w acetone–water at 0 °C. The results are discussed with reference to the mechanisms of the hydrolyses. The volume and entropy of activation of the acid-catalyzed hydrolysis are −17.1 ± ~1.3 cm3 mole−1 and ~ −20 cal deg−1 mole−1, showing that the mechanism[Formula: see text]suggested because the rate was proportional to Hammett's h0, is not correct. It follows that the Zucker–Hammett hypothesis is invalid for this reaction, as we have shown previously for other reactions, and hence that it does not provide a valid method of distinguishing between the A-1 and A-2 mechanisms.
THE LOW TEMPERATURE PREPARATION OF ANHYDROUS TITANIUM IV BROMIDE AND ANHYDROUS TITANIUM IV IODIDE FROM BENZENE SOLUTIONS
Authors: Gayer Karl H. , Tennenhouse Gerald
Published: May 2006

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THE EFFECT OF AMINES AND PHENOLS ON THE GAS-PHASE OXIDATION OF n-BUTANE AND ISOBUTANE
Authors: Ingold K. U. , Puddington I. E.
Published: May 2006

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PHOTOCHEMICAL SEPARATION OF MERCURY ISOTOPES: V. FURTHER STUDIES ON THE REACTION OF Hg2026(3P1) ATOMS, PHOTOEXCITED IN NATURAL MERCURY VAPOR, WITH HYDROGEN CHLORIDE
Authors: McDowell J. R. , McDonald C. C. , Gunning H. E.
Published: May 2006

A further study has been made of the reaction of Hg2026(3P1) atoms, in natural mercury vapor (HgN), with hydrogen chloride under flow conditions at room temperature. Emphasis has been placed in this study on the effect of reaction parameters and mercury-recovery techniques on the Hg202 content of the solid calomel formed in the reaction.For pure hydrogen chloride the Hg202 content of the calomel was found to be 39.9 ± 0.3%, compared to the natural abundance of 29.8%. With 20–40 mole % of butadiene-1,3 in the hydrogen chloride, calomels containing 83–84% of Hg202 were consistently obtained.The isotopically specific aspects of the reaction in pure hydrogen chloride can be adequately explained by the sequence:[Formula: see text]where M in reaction [3] is a third body or the wall. From the Hg202-abundance data and steady-state considerations, it has been shown that the ratio of partitioning of the absorbed radiation to [1] and [2], respectively, = Φ1/Φ2 = 0.40 ± 0.02. In short, 29% of the primary reaction proceeds by the isotopically specific step [1].The Hg202 content of the calomel product was found to increase markedly when unsaturated hydrocarbons were added to the hydrogen chloride stream. The addends studied included butadiene-1,3, benzene, isoprene, acetylene, propylene, and ethylene in order of decreasing effectiveness. In the presence of the unsaturated addend (U) two additional reactions were postulated to occur:[Formula: see text]From steady-state calculations the effectiveness of the addend can be shown to be determined by the rate ratio, k8/k4.For the maximally enriching mixture of hydrogen chloride and butadiene, the effect of variations in lamp temperature and reaction pressure was studied. At lamp temperatures exceeding approximately 35 °C, reduced enrichments were obtained owing to emission-line broadening. A progressive reduction in enrichment was also observed with substrate pressures greater than 25 mm, owing presumably to Lorentz-broadening of the hyperfine absorption contours of the HgN in the reaction cell.The Hg202 content of the calomel product was determined by resonance radiation absorbiometry. The apparent Hg202 abundances of the mercury recovered from the calomel product were found to depend strongly on the method used for isolating the enriched mercury from the calomel. Evidence was obtained for the occurrence of isotopically degradative exchange reactions during the recovery process. A recovery technique was developed which appeared to eliminate this exchange degradation.