bluuebunny/crossref_metadata_2025 huggingface dataset:
FRACTIONATION OF GERMANIUM ISOTOPES IN CHEMICAL REACTIONS
Authors: Brown H. M. , Krouse H. R.
Published: May 2006

Isotopic vibrational frequencies and the corresponding partition-function ratios for several compounds containing Ge70 and Ge76 have been calculated at various temperatures. The theoretical equilibrium constants for germanium isotope-exchange reactions derived from these partition-function ratios indicate that noticeable germanium isotope fractionation might be effected with laboratory reactions. Calculated kinetic isotope effects in the breaking of diatomic bonds also predict observable alterations of the Ge70/Ge76 ratio.A kinetic isotope effect of 1.0% observed in the chemical reduction of GeO2 to GeO is discussed.
THE RADIATION CHEMISTRY OF AQUEOUS SOLUTIONS OF CHLORAL HYDRATE AND OF BROMAL HYDRATE
Authors: McIntosh R. G. , Eager R. L. , Spinks J. W. T.
Published: May 2006

The radiation chemistry of aqueous solutions of chloral hydrate and of bromal hydrate has been further investigated. The electrical conductivity method of Andrews and Shore (1) was used to follow the appearance of acid. The yield of acid was found to be dependent on the dose rate, contrary to the conclusion reached by Andrews and Shore but in agreement with the results of other workers. A reexamination of Andrews and Shore's paper indicates that an incorrect interpretation was made of their data and reveals that, in fact, their data also indicate a dose rate dependence for the yield of acid. A free radical mechanism is proposed which is in good agreement with the observed dependence of the rate of formation of acid upon the dose rate and upon the solute concentration in both the presence and in the absence of oxygen.
CONSTITUTION OF A SYNTHETIC GLUCAN: III. PERIODATE OXIDATION
Authors: Dutton G. G. S. , Unrau A. M.
Published: May 2006

A synthetic glucan known to contain D-glucofuranose and D-glucopyranose units was subjected to a Smith periodate degradation. After mild acid hydrolysis any aldehydic compounds were oxidized with bromine and the neutral fragments separated from the acidic by ion exchange resins. The acidic portion, after lactonization and reduction, gave glycerol and a series of oligosaccharides. The neutral portion was resolved into glycerol, erythritol, and a series of seven fractions containing glycosides with degrees of polymerization up to eight. Each fraction which was homogeneous by paper chromatography contained at least two components. Some of these individual components were separated as their trimethylsilyl derivatives by vapor phase chromatography and the following glycosides were identified: 1-O-(α-D-glucopyranosyl)-glycerol, 1-O-(β-D-glucopyranosyl)-glycerol, 2-O-(D-xylofuranosyl)-D-erythritol, 2-O-(α-D-glucopyranosyl)-D-erythritol, 2-O-(β-D-glucopyranosyl)-D-erythritol, 1-O-(D-glucopyranosyl)-erythritol. These results demonstrate for the first time the separation of Smith degradation products by vapor phase chromatography. The presence in the polysaccharide of α and β linkages and the existence of D-glucofuranose residues are confirmed. The highly branched nature of the polymer is shown by the fact that four successive periodate oxidations and mild hydrolyses were necessary to oxidize all the hexose units.
FAR INFRARED AND RAMAN SPECTRA AND STRUCTURE OF DITHIOPHOSGENE
Authors: Busfield W. K. , Taylor M. J. , Whalley E.
Published: May 2006

The infrared spectrum in the range 3000–50 cm−1and the Raman spectrum of solutions of dithiophosgene have been obtained. There are no coincidences in the infrared and Raman spectra, and the only structure consistent with this and approximately tetrahedral carbon valencies is[Formula: see text]that is tetrachloro-1,3-dithietane, in which the ring is planar or nearly planar. A tentative assignment of the observed bands is given on the basis of D2hsymmetry.
THE RELATIVE EASE OF REDUCTIVE CLEAVAGE OF 1,3-DIOXOLANES AND 1,3-DIOXANES IN ETHER SOLUTION BY LiAlH4–AlCl3
Authors: Leggetter B. E. , Diner U. E. , Brown R. K.
Published: May 2006

In ether solution, 1,3-dioxolanes are hydrogenolyzed faster by LiAlH4–AlCl3 than are the corresponding 1,3-dioxanes. This difference is attributed to the relative ease of oxocarbonium ion formation in the rate-determining step of the reaction. The results obtained have been utilized to explain the selective cleavage of the five- and six-membered acetal structures found in the polyacetals of hexitols.
THE THERMAL UNIMOLECULAR DECOMPOSITION OF Δ2,5-BICYCLO[2.2.1]HEPTADIENE
Authors: Roquitte B. C.
Published: May 2006

not available
FURTHER INVERSE GAMMA-DEUTERIUM ISOTOPE EFFECTS IN SOLVOLYTIC REACTIONS
Authors: Blandamer M. J. , Robertson R. E.
Published: May 2006

not available
A SUBLIMATION PROCEDURE FOR THE PURIFICATION OF ORGANIC SUBSTANCES AT LOW TEMPERATURES
Authors: Petrucci Ralph H. , Edsall Barbara L.
Published: May 2006

not available
HIGH PRIMARY QUANTUM EFFICIENCY IN THE REACTION OF NEOPENTANE WITH Hg 6(3P1) ATOMS
Authors: Norstrom R. J. , Strausz O. P. , Gunning H. E.
Published: May 2006

not available
THE HYDROGEN–CHLORINE SYSTEM IN THE MM PRESSURE RANGE: I. ENERGY DISTRIBUTION AMONG VIBRATIONALLY EXCITED STATES
Authors: Findlay F. D. , Polanyi J. C.
Published: May 2006

When atomic plus molecular hydrogen coming from a Wood's discharge tube are mixed with molecular chlorine, infrared emission is observed (1). At low reagent pressures, ~10−2 mm Hg, this emission can be related to the relative rate of the reaction H + Cl2 → HCl†ν + Cl proceeding to form HCl in vibrationally excited states ν = 1–6, of the ground electronic state. In the present work this system has been investigated for the first time at ~100 × the reagent pressure (~1 mm Hg). The reaction was shown to proceed by a chain mechanism. The translational–rotational temperature was 1300 ± 100 °K under the experimental conditions normally used. The vibrational distribution was notable for the presence of vibrators in levels ν = 7 and 8, which are respectively 4 and 10 kcal higher in energy than the exothermicity of the H + Cl2 reaction. The population in these levels appeared to be related to that in the levels with [Formula: see text]; it was proposed that vibrational–vibrational exchange among these lower levels was responsible for populating the higher ones. A simple model yielded a collision efficiency for HCl†ν=1 + HCl†ν=6 → HCl†ν=7 + HCl†ν=0, of Z1,6t = 6 × 103 collisions per transfer. Addition of HCl to the reaction mixture brought about a redistribution among vibrationally excited states indicative of a fast vibrational transfer, HClν=0 + HCl†ν=2 → 2 HCl†ν=1.At reduced pressure of HCl† the stationary-state distribution among higher vibrational states approximated closely to that observed at 10−2 mm Hg total pressure (where collisional deactivation is insignificant), suggesting that collisional deactivation was not of major importance even at the pressure used in the present work. In order to account for the high translational–rotational temperature, in the absence of substantial vibrational deactivation, it was necessary to suppose that the greater part of the energy liberated by the reaction H + Cl2 went directly into translational and rotational motion of the products.
ORGANIC COMPLEXES OF URANIUM: PART I. THE SYNTHESIS AND SPECTRUM OF URANYL PHTHALOCYANINE
Authors: Bloor J. E. , Schlabitz J. , Walden C. C. , Demerdache A.
Published: May 2006

The preparation of uranyl phthalocyanine from uranyl chloride and dilithium phthalo-cyanine is described. The infrared and electronic spectra of the complex are quite different from that previously reported for uranyl phthalocyanine and it is suggested that previous workers obtained mainly a mixture of phthalocyanine (PcH2) and inorganic uranyl compounds. The infrared spectra of α- and β-PcH2, β-PcCu, PcLi2, and PcUO2 from 4000 to 300 cm−1; the far infrared spectra of β-PcH2, β-PcCu, and PcUO2 from 300 to 100 cm−1; and the electronic spectrum from 3500 to 10 000 Å of PcUO2 in 1-chloronaphthalene are recorded. A tentative assignment of a band at 278 cm−1 to the O—U—O bending frequency is made. The electronic spectrum of PcUO2 differs from previous spectra of metal phthalocyanines in that it possesses no strong absorption in the 6000–7000 Å region. It does, however, have a strong band at 9145 Å, ε = 4.15 × 104.
THERMODYNAMICS OF TERNARY UNIVARIANT SYSTEMS OF THE TYPE: WATER – METAL SALT – ACID
Authors: Lorimer J. W.
Published: May 2006

Thermodynamic equations for the variation of vapor pressure and composition with temperature along ternary univariant lines on phase diagrams of systems typified by H2O–ZnSO4–H2SO4 are developed. The usefulness of these equations in testing the consistency of experimental data, in estimating invariant points, and in obtaining thermodynamic data is discussed.
PHOTO-INITIATED REACTIONS OF THIOLS AND OLEFINS: I. THE THIYL RADICAL CATALYZED ISOMERIZATION OF BUTENE-2 AND 1,2-ETHYLENE-d2
Authors: Graham D. M. , Mieville R. L. , Sivertz C.
Published: May 2006

Kinetic studies have been made of the isomerization of butene-2 and 1,2-ethylene-d2 catalyzed by thiyl radicals produced from the photolysis of methanethiol. The rate of isomerization was found to be first order with respect to both the olefin and [Formula: see text] concentrations. The lack of influence of pressure on the reaction rate, at pressures above about 4 mm, leads to a simple mechanism in which isomerization is considered to occur as a result of thermal decomposition of the collisionally stabilized adduct radical produced in the reaction [Formula: see text]. The rate constants for this attack step were found to be 2 × 107 and 4.8 × 106 l mole−1 s−1 for butene-2 and ethylene-d2, respectively. In both cases the activation energy for isomerization was found to be close to zero. From a kinetic study of the isomerization of cis-butene-2 in the presence of butadiene-1,3, which acts as a retarder, the attack constant for butadiene at 25 °C was found to be 4.5 × 108 l mole−1 s−1.
IONIZATION POTENTIALS OF METHYL-SUBSTITUTED BENZENES AND CYCLOPENTADIENES
Authors: Meyer F. , Harrison A. G.
Published: May 2006

The ionization potentials of a number of methyl-substituted benzenes and cyclopentadienes have been measured by electron impact. The experimental results are compared to calculations based on a group orbital method.
PROTONATION SITE IN ORGANIC BASES FROM INFRARED X—H DEFORMATION MODES
Authors: Cook Denys
Published: May 2006

The infrared absorption bands due to X—H stretching modes in protonated bases are diagnostically of little value in determining the protonation site. However, the deformation mode, δXH, shows promise of becoming a useful group frequency whose value is characteristic of the type of atom protonated. The following values, which have been confirmed by deuterium substitution of the sensitive hydrogen atom, are typical:[Formula: see text]Occasionally splittings occur so that two components of the bending mode are observed. These have been attributed in many cases to correlation field coupling in the solid state.
THE SYNTHESIS OF β-GALACTO- AND β-GLUCO-PYRANOSYL DISACCHARIDES BY SPOROBOLOMYCES SINGULARIS
Authors: Gorin P. A. J. , Spencer J. F. T. , Phaff H. J.
Published: May 2006

Synthesis of β-D-galactopyranosyl disaccharides takes place in growing cultures of Sporobolomycessingularis containing lactose and a sugar acceptor. The products of galactosyl transfer using various acceptors arise mainly from substitution of secondary rather than primary hydroxyl groups. The minimal structural requirement for reaction with the acceptor appears to be a hydroxyl vicinal to the substituted hydroxyl group. A mechanism that accounts for the formation of secondary disaccharides is postulated.The organism also contains a β-glucosidase which transfers O-β-D-glucopyranosyl groups from cellobiose to sugar acceptors. The positions of the glycosidic linkages in the disaccharide products are identical with those formed in the corresponding galactosyl transfer reaction.
THE KINETICS OF THE INHIBITED AUTOXIDATION OF TETRALIN
Authors: Howard J. A. , Ingold K. U.
Published: May 2006

The kinetics of the inhibition of the autoxidation of tetralin by 2,6-di-t-butyl-4-methylphenol, phenol, and 4-methoxyphenol have been investigated at 65 °C. The highly hindered 2,6-di-t-butyl-4-methylphenol follows simple first order kinetics and exhibits a normal deuterium isotope effect (kH/kD = 10). The kinetics with phenol are complicated by the fact that the phenoxy radical can abstract a hydrogen atom from both tetralin and its hydroperoxide. This leads to oxidation rates which are inversely proportional to the square root of the phenol concentration. The deuterium isotope effect has about the value to be expected in view of this square root relation. The kinetics with 4-methoxyphenol result from chain transfer and from chain termination by the coupling of 4-methoxyphenoxy radicals. The isotope effect varies between zero and a value that approaches the upper limit of about 10 at low inhibitor concentrations.
RING MIGRATION IN ALKYLATED FERROCENES
Authors: Bublitz Donald E.
Published: May 2006

Alkylferrocenes have been found to undergo disproportionation to ferrocene and 1,1′-di-alkylferrocenes in the presence of aluminium or gallium chloride. The mechanistic pathway has been shown to involve (π-ligand)–(π-ligand) exchange as opposed to the usual carbon–carbon cleavage found in benzene chemistry.
SYNTHESIS OF THIOHYDROXIMATES THE ADDITION OF THIOLS TO NITRILE OXIDES
Authors: Benn M. H.
Published: May 2006

The addition of thiols to nitrile oxides is shown to constitute a general synthesis of thiohydroximates.
AN ATTEMPT TO STUDY COMPLEX FORMATION BETWEEN 1,3,5-TRINITROBENZENE AND OLEFINS BY GAS CHROMATOGRAPHY
Authors: Cvetanovié R. J. , Duncan F. J. , Falconer W. E.
Published: May 2006

An attempt has been made to study complex formation between 1,3,5-trinitrobenzene (TNB) and olefins by a gas chromatographic technique. A particular interpretation of the data indicates that the TNB – olefin complexes exhibit progressive increases in stability with increasing double-bond substitution. Steric effects are less pronounced than for olefin complexes with silver nitrate or molecular iodine. Olefins are well separated by carbon number, and differences in retention times among the structural isomers of each molecular weight are sufficiently characteristic to provide a basis for assigning major structural features.
CHEMICAL SCAVENGER PROBE STUDIES OF ATOM AND EXCITED MOLECULE REACTIVITY IN ACTIVE NITROGEN FROM A SUPERSONIC STREAM
Authors: Fontijn A. , Rosner D. E. , Kurzius S. C.
Published: May 2006

A quartz chemical scavenger probe has been developed to study the local composition of supersonic electrically discharged gas streams. The probe samples the central portion of a nonequilibrium jet and allows direct comparison with other local measurement techniques (e.g. differential catalytic detectors) for determining active species concentrations. Active nitrogen from a Mach 3 stream was sampled and reacted inside the probe with one of the scavenger gases NO, NH3, or C2H4at 18.8 mm Hg and at an average temperature of 500 °K. Limiting values of the NO destruction rate and the HCN production rate were observed; however, NH3destruction exhibited no plateau. The observed maximum rate of NO destruction was 2.1 times as large as the NO flow rate at the light titration end-point. This difference is attributed to a reaction of NO, added in excess of the titration end-point flow, with metastable electronically excited molecules formed within the discharge zone. The converging-diverging supersonic nozzle-glow discharge source used in these experiments apparently delivers metastable excited molecules to the reaction zone in a higher relative concentration than do the more conventional subsonic electrical discharge flow systems used for most previous active nitrogen studies.
KINETICS OF THE REACTION H + D2 = HD + D
Authors: Schulz W. R. , Roy D. J. Le
Published: May 2006

The authors have measured the rate constant for the reaction H + D2 = HD + D in the temperature range 368–68° K. This was found to be given by the relation:[Formula: see text]A comparison is made with previous experimental and theoretical work on the reaction.
CHARACTERISTIC VIBRATIONAL FREQUENCIES OF COMPOUNDS CONTAINING Si—O—Si, P—O—P, S—O—S, AND Cl—O—Cl BRIDGING GROUPS FORCE CONSTANTS AND BOND ORDERS FOR THE BRIDGE BONDS
Authors: Gillespie R. J. , Robinson E. A.
Published: May 2006

The assignment of characteristic frequencies for the X—O—X group in compounds containing Si—O—Si, P—O—P, S—O—S, and Cl—O—Cl bonds is discussed with reference to the vibrational spectra of disiloxanes, diphosphoryl, and disulphuryl compounds and dichlorine heptoxide. The stretching force constants of the X—O—X bridging bonds have been obtained by treating the molecules as simple triatomic species X2O• X—O bond orders and bond lengths have been calculated from the stretching force constants and the calculated and observed bond lengths are compared. The variation in the observed X—O—X angles is related to the bond orders and is discussed in terms of the electron-pair repulsion theory. It is shown that bond orders in the isoelectronic series Si2O76−, P2O74−, S2O72−, and Cl2O7 may be simply deduced from the empirical rule that the valency shell of a second-row element tends to be occupied by twelve electrons (the duodecet rule).
π-ELECTRON DENSITIES IN THE PYRIDINIUM CATION THE EFFECT OF THE COUNTERION ON THE PROTON MAGNETIC RESONANCE SPECTRUM
Authors: Kotowycz G. , Schaefer T. , Bock E.
Published: May 2006

Proton shifts relative to internal benzene of pyridine hydrochloride, hydrobromide, and hydriodide in methylene chloride, acetonitrile, nitromethane, and formic acid are reported. A model involving a hydrogen-bonded ion pair between the pyridinium cation and the counterion is discussed. It is assumed that the counterion reduces considerably the π-electron polarization in the pyridinium ion calculated for the isolated ion by the V.E.S.C.F. method. If the electric fields arising from the π-electrons, the counterion, and the positive charge in the N—H+ sigma bond are taken into consideration, the observed order of the C—H proton shifts is predicted. The N—H+ proton shifts are sensitive to the counterion, the solvent, and traces of water. In formic acid the N—H+ proton shifts of the hydrochloride and hydrobromide are characteristic of the solvent only. In these two cases the N—H+ proton does not exchange rapidly and an 14N—H+ coupling constant of 67.6 ± 0.5 c/s is found.
SOME BASICALLY SUBSTITUTED CAMPHANES
Authors: Wei Ling , Steck Edgar A.
Published: May 2006

not available
LOW-TEMPERATURE PYROLYSIS: I. THE PYROLYSIS OF HYDROGEN PHTHALATE ESTERS OF SOME TERTIARY ALCOHOLS
Authors: Rutherford K. G. , Fung D. P. C.
Published: May 2006

Some hydrogen phthalate esters of tertiary alcohols have been subjected to liquid phase pyrolysis. Olefinic mixtures and phthalic acid are the only products of the reaction. A study of the olefin distribution for each of the compounds pyrolyzed was made. Evidence of ionic character in liquid phase pyrolysis is presented.
THE 19F N.M.R. SPECTRUM OF IF7
Authors: Gillespie R. J. , Quail J. W.
Published: May 2006

It is shown that the line shape calculated for the n.m.r. spectrum of a magnetic nucleus attached to a nucleus of spin 5/2 undergoing quadrupole relaxation agrees well with the observed spectrum of iodine heptafluoride. The iodine–fluorine coupling constant was found to be[Formula: see text] The apparent magnetic equivalence of the fluorine atoms in IF7 is discussed.
FURTHER ALKALOIDS RELATED TO ASPIDOALBINE AND LIMASPERMINE
Authors: Ferrari C. , Marion Léo
Published: May 2006

The stem bark of Aspidospermaalbum (Vahl) R. Ben. is shown to contain at least eight more alkaloids than had been reported previously. The new alkaloids have been separated from the extract by a combination of countercurrent distribution and preparative scale thin-layer chromatography. Of these eight alkaloids, five have been definitely characterized and their structure determined. They are the previously known aspidolimidine, together with N-propionyl-N-deacetylaspidolimidine, N-acetyl-N-depropionyllimaspermine, N-acetyl-N-depropionylaspidoalbinol, and aspidolimidinol. The natural occurrence of the last four alkaloids had not been reported previously.
REACTION OF LOWER OLEFINS AND IODINE IN A LIQUID PHASE: NOVEL PREPARATION OF ALKENE IODOHYDRINS
Authors: Sumrell Gene , Wyman Bert M. , Howell Ronald G. , Harvey Mack C.
Published: May 2006

A simplified procedure for preparing alkene iodohydrins has been developed utilizing olefin diiodide, aqueous acetone, and hydrogen peroxide. It was learned in this work that, contrary to general information in the literature, lower alkenes and iodine react quickly and essentially completely in a liquid phase at room temperature to give the diiodide.
THE CRYSTAL STRUCTURE OF K2TeBr6
Authors: Brown I. D.
Published: May 2006

Crystals of K2TeBr6are monoclinic, space group [Formula: see text] with a = 7.521, b = 7.574, and c = 10.730 Å; β = 89° 40′. Atomic positions have been found by three dimensional X-ray diffraction analysis (least squares R = 0.12). The crystals possess a K2PtCl6structure which is distorted to allow a more efficient packing of the comparatively large anions than is possible with the undistorted cubic form. The stereochemistry of the octahedral TeBr6−ion (Te—Br = 2.71 Å) is discussed.
SUBSTITUTED METHANES: PART XXXVI. CALCULATED WAVE NUMBERS, ASSIGNMENTS, AND THERMODYNAMIC PROPERTIES FOR CH2DI AND CD2HI, AND CALCULATED ROTATIONAL DISTORTION CONSTANTS AND MEAN AMPLITUDES FOR CH3I AND CD3I
Authors: Ditzel Earle F. , Meister Arnold G. , Piotrowski Edward A. , Cleveland Forrest F. , Sarma Y. Anantarama , Sundaram S.
Published: May 2006

A set of potential energy constants has been obtained for CH3I and CD3I from their vibrational spectral data. From these constants, the rotational distortion constants and the mean amplitudes have been calculated for these two molecules. The rotational distortion constants DJ, DJK, and DK were, respectively, CH3I, 6.34, 59.36, and 3 542.30; CD3I, 3.90, 33.08, and 866.43 kc/s. The principal mean amplitudes of vibration in pm (pm = picometer = 10−12 meter = 10−2 Å) at 298.16°K are CH3I, 5.25 (C—I), 7.71 (C—H), 12.37 [Formula: see text], and 12.00 [Formula: see text]; CD3I, 5.14 (C—I), 6.63 (C—D), 10.85 [Formula: see text], and 10.65 [Formula: see text]. The potential energy constants were used to obtain the wave numbers of CH2DI and CD2HI. A complete assignment of the observed wave numbers for the molecules CH2DI and CD2HI has been made. The fundamental wave numbers for the gaseous state of CH2DI are a′, 2 980, 2 235, 1 418, 1 170, 723, and 519; a″, 3 091, 1 266, and 871 cycles/cm. For CD2HI, the corresponding values are a′, 3 017, 2 174, 1 185, 1 009, 757, and 508; a″, 2 273, 1 279, and 676. With these wave numbers, the thermodynamic functions have been calculated for the two molecules for 12 temperatures from 100 to 1 000°K for 1 atm pressure. The values of (H0−E00)/T, −(F0−E00)/T, S0, and Cp0 at 298.16°K are, respectively, CH2DI, 8.82, 54.66, 63.48, and 10.98; CD2HI, 9.00, 55.20, 64.19, and 11.53 cal deg−1 mole−1.
ANIONIC POLYMERIZATION OF ISOPRENE
Authors: Worsfold D. J. , Bywater S.
Published: May 2006

The polymerization of isoprene with butyllithium in cyclohexane has been studied. The initiation reaction was found to be complex; plots of conversion of butyllithium against time are sigmoidal. The order with respect to the initiator was found to be between one-half and one. The order of the isolated propagation reaction in polyisoprenyllithium was found to be one-quarter and was correlated with a fourfold association of active chain ends determined by dilute solution light-scattering measurements.The major effect of tetrahydrofuran on the reaction was the great increase of the initiation rate. The kinetic order changes slowly with the addition of small amounts of tetrahydrofuran, suggesting that the aggregates are broken down with difficulty. The microstructure of the polymer has been determined by n.m.r. measurements and shows a steady transition from a largely 1:4 to a largely 3:4 structure as the polarity of the solvent is increased by the addition of tetrahydrofuran.
PRÉPARATION D'ESTERS ORTHOTHIOBORIQUES A PARTIR DU SULFURE DE BORE
Authors: Brault J. , Lalancette J. M.
Published: May 2006

not available
THE SYNTHESIS OF 5-MERCAPTOTRYPTAMINE, THE THIOL ANALOG OF SEROTONIN
Authors: Horner J. Kenneth , Skinner W. A.
Published: May 2006

not available
THE OXYMERCURATION OF 4-METHYLENECYCLOHEXANEMETHANOL
Authors: Weinberg N. L. , Wright George F
Published: May 2006

The oxymercuration of 4-methylenecyclohexanemethanol in tert-butyl alcohol yields 1-chloromercurimethylnorcineole which may be converted to 1-methylnorcineole by borohydride reduction or to 4-chloromercurimethyl-4-↑-hydroxycyclohexane-↓-carboxylic acid. This may be deoxymercurated to 4-methylenecyclohexanecarboxylic acid and reduced with borohydride to 4-↓-methyl-4-↑-hydroxycyclohexane-↓-carboxylic acid.
SULFONIUM SALT SOLVOLYSIS: PART V. MODEL SYSTEMS FOR BIOLOGICAL TRANSMETHYLATION
Authors: Hyne James B. , Jensen James H.
Published: May 2006

The rates of solvolysis of a series of sulfonium salts which may be considered as models for the biologically important sulfonium salt, S-adenosylmethionine, are discussed in terms of a possible anchimeric role of the carboxyl group of methionine in transmethylation reactions.
A SIMPLIFIED PROCEDURE FOR THE ANALYSIS OF COMPLEX NUCLEAR MAGNETIC RESONANCE SPECTRA: I. THE PRINCIPLES OF SUB-SPECTRAL ANALYSIS
Authors: Diehl P. , Jones R. G. , Bernstein H. J.
Published: May 2006

A general procedure for the analysis of complex n.m.r. spectra has been developed in terms of simpler sub-spectra. The method is applicable to all possible combinations of magnetically equivalent and non-equivalent, strongly and weakly coupled groups of nuclei. It includes the special case of the composite particle model as well as the effective frequency method.The method is applied, as an example, to the ABB′XX′ spectrum of pyridine where the parameters JAB,JAX, the sum of JBX + JBX′, δAB, and δAX are derived without complete analysis of the spectrum, from the AB2 sub-spectra of the problem.
OXYGEN-17 NUCLEAR MAGNETIC RESONANCE STUDY OF THE CHROMATE REACTION WITH DICHROMATE
Authors: Figgis B. N. , Kidd R. G. , Nyholm R. S.
Published: May 2006

The 17O n.m.r. spectra from aqueous solutions containing both chromate and dichromate ions have been obtained over a range of concentrations. Signals from both the bridging oxygen and the terminal oxygens in the dichromate ion have been observed. The line widths for the dissolved species were found to be concentration dependent. The variations in line width have been ascribed to a rapid reaction occurring at equilibrium between chromate and dichromate ions. The bimolecular rate constant for the reaction is 2.3 ± 0.4 × 103 1 mole−1 s−1 at 27 °C. The reaction mechanism is discussed in the general context of nucleophilic attack on dichromate ion. A comparison of this rate constant with those for the analogous reaction using different nucleophiles indicates that it is polarizability rather than basicity which determines nucleophilic reactivity towards Cr2O7−.
FORMATION DES DÉRIVÉS PENTAFLUOROSULFURES ÉTHYLÈNIQUES, DIÈNIQUES ET ACÉTYLÈNIQUES
Authors: Tremblay Méùde
Published: May 2006

The reaction of disulfur decafluoride with olefins, dienes, and acetylenes has been studied under pressure at 125–140 °C. The gases formed have been separated and identified with a gas chromatograph coupled to a time-of-flight mass spectrometer. Liquid pentafluorosulphur derivatives, studied by mass spectrometry, were attributed the following structures: CH2FCHClSF5, CH2FCHBrSF5, CH2FCHBrCH2CHBrSF5, CH2FCHFCH2CHFSF5, and CH2=CHCHFCH2SF5. Addition compounds of dienes or acetylenes have structures assumed to be FCH2CF2CH2SF5 from propadiene and C2H5CF2CHFSF5 from ethyl acetylene.
ELECTRON SPIN RESONANCE STUDIES OF RADICAL ANIONS AND ION PAIRS IN THE PYRAZINE SERIES
Authors: McDowell C. A. , Paulus K. F. G.
Published: May 2006

The alkali metal hyperfine interaction in ion pairs of sodium and potassium cations with the radical anions of some methyl-substituted pyrazines and pyridines has been investigated. The electrostatic, electronic, and steric interactions which influence the metal hyperfine splitting are discussed in detail. It is proposed that the variation of the observed hyperfine splitting is due, in some cases, to steric effects, but in the series of m-xylene, 3,5-dimethylpyridine, and 2,6-dimethylpyrazine, the variation is caused by a change in the energy of electronic excitations from the anion to the cation.The results of molecular orbital calculations of the spin densities in tetramethylpyrazine and 3,5-dimethylpyridine are compared with experiment and found to give reasonable agreement.
KINETICS AND MECHANISMS OF THE THERMAL DECOMPOSITION OF PROPIONALDEHYDE: PART II. THE REACTION IN THE PRESENCE OF NITRIC OXIDE
Authors: Laidler K. J. , Eusuf M.
Published: May 2006

The decomposition of propionaldehyde in the presence of various amounts of nitric oxide has been studied in the temperature range 520–560 °C and at propionaldehyde pressures from 30 to 300 mm Hg. The reaction is inhibited by small amounts of nitric oxide, and larger amounts give rise to strong catalysis. The order of the maximally inhibited reaction is 1.5 and the degree of inhibition decreases with an increase of propionaldehyde pressure. In the catalytic region the order of the overall reaction is 1.25 with respect to propionaldehyde, and the relative rate (the ratio of rates in the presence and absence of nitric oxide) is independent of propionaldehyde pressure. The overall rate in the catalytic region can be expressed as[Formula: see text]the unit of concentration being mole per cc. A mechanism in which nitric oxide initiates chains by the reaction C2H5CHO + NO → C2H5CO + HNO, propagates them by C2H5NO + C2H5CHO → C2H6 + C2H5CO + NO, and terminates them by C2H5 + C2H5NO → C4H10 + NO and C2H6 + C2H4 + NO and C2H5NO + C2H5NO → C4H10 + 2NO or C2H6 + C2H4 + 2NO is proposed and is shown to be consistent with the results.
THE ADSORPTION OF KRYPTON AND ETHYLENE ON EVAPORATED FILMS OF MAGNESIUM
Authors: Young D. M. , Anderson C. D.
Published: May 2006

not available
PAPER CHROMATOGRAPHY OF SOME AMINE HYDROCHLORIDES AND ACETATES IN ACIDIC SOLVENT SYSTEMS
Authors: Bannard R. A. B. , Casselman A. A.
Published: May 2006

The chromatography of piperidine, cyclohexylamine, benzylamine, and morpholine hydrochlorides on unwashed Whatman No. 1 and No. 17 papers in t-butanol: acetic acid: water (2:1:1) leads in each case to partial conversion to the acetate salt, the mobility of which differs from that of the hydrochloride. The interconversion is reduced but is not prevented by the use of acid-washed papers and is increased again when the acid-washed papers are treated with sodium, potassium, calcium, or magnesium acetate prior to chromatography. The salt interconversion is continuous during development of the chromatograms, extended development leading to complete disappearance of the hydrochloride. Quantitative chromatography of piperidine and morpholine hydrochlorides revealed that the extent of salt interconversion is ca. 12% on unwashed and calcium ion washed Whatman No. 17 papers, ca. 6% on sodium ion washed papers, and ca. 1% on acid-washed papers. Piperidinium ions become bound to unwashed, acid-washed, and salt-washed Whatman No. 17 papers during chromatography in aqueous solution just as they do to the hydrogen, sodium, and calcium forms of the carboxylate ion exchanger Amberlite IRC-50 under similar conditions, indicating that a cation exchange mechanism involving carboxyl groups in the paper is responsible for the observed salt interconversion.
SIMULTANEOUS POLAROGRAPHIC DETERMINATION OF SMALL AMOUNTS OF BISMUTH AND LEAD IN COPPER-BASE ALLOYS
Authors: McMaster C. H.
Published: May 2006

The extraction of metal diethyldithiocarbamate complexes into chloroform from an alkaline solution containing cyanide and citrate ions is a convenient means of separating small amounts of bismuth and lead from copper and uranium, and from the elements normally found in copper-base alloys. After the separation, bismuth and lead are determined polarographically using an acidic tartrate solution as the supporting electrolyte.The method is applicable to the determination of bismuth and lead, in the concentration range from 0.0005–0.05%, in copper-base alloys of widely different composition.
PYRROLE CHEMISTRY: IV. THE PREPARATION AND SOME REACTIONS OF BROMINATED PYRROLE DERIVATIVES
Authors: Anderson Hugh J. , Lee Shu-Fan
Published: May 2006

Methyl 2-pyrrolecarboxylate and 2-pyrrolecarboxaldehyde have been brominated under a variety of conditions and the isomer ratios determined. The products have been identified as the 4-bromo, 5-bromo, and 4,5-dibromo derivatives and their structures proved. It has been shown that the bromine group in these products is not easily displaced by nucleophiles although this has been accomplished with the cyanide ion. The bromine has been removed easily by catalytic hydrogenation.
THE OXYGENATED FATTY ACIDS FROM THE OIL OF THE SPORES OF LYCOPODIUM SPECIES
Authors: Tulloch A. P.
Published: May 2006

The oil from the spores of commercial Lycopodium, mainly L. complanatum, contains cis-9,10-epoxyoctadecanoic acid (2%), (+)-8-hydroxyhexadecanoic acid (7%), and (±)-threo-9,10-dihydroxyoctadecanoic acid (4%). Smaller amounts of 8-oxohexadecanoic acid and an epoxyhexadecanoic acid also seem to be present.
THE CRYSTAL STRUCTURE OF α-Zn3(PO4)2
Authors: Calvo Crispin
Published: May 2006

α-Zn3(PO4)2 crystallized in the monoclinic space group C2/c with lattice parameters a = 8.14 ± 0.02 Å, b = 5.63 ± 0.01 Å, c = 15.04 ± 0.04 Å, β = 105°08′ ± 05′, and Z = 4. The cations are found in two types of tetrahedrally coordinated sites. One-third of the cations lie on twofold axes within an oxygen tetrahedron. The remaining cations are found in a pair of edge-sharing oxygen atom tetrahedra. The green emission of Mn++ in α-Zn3(PO4)2 is consistent with Mn++ substituting for Zn++ in either tetrahedral site.
REARRANGEMENT STUDIES WITH 14C. XXII. SOLVOLYSES OF 1-14C-ETHYL p-TOLUENESULFONATE
Authors: Lee C. C. , Frost Moira K.
Published: May 2006

not available
THE REACTION OF SOME AROMATIC ACIDS WITH SODIUM AZIDE IN A TRIFLUOROACETIC ACID – TRIFLUOROACETIC ANHYDRIDE MEDIUM
Authors: Rutherford K. G. , Ing (Yu) Sandra Yuen-Shun , Thibert R. J.
Published: May 2006

Some commercially available aromatic acids have been treated with sodium azide using a mixture of trifluoroacetic acid and trifluoroacetic anhydride as the reaction medium. Benzoic, ortho-, meta-, and para-toluic, ortho-bromo-, and ortho-nitro-benzoic acids were converted to corresponding N-substituted trifluoroacetamides in good yields. 1-Naphthoic acid was converted to N-(1-naphthyl)-trifluoroacetamide in near quantitative yield. Meta- and para-bromobenzoic and meta- and para-nitrobenzoic acids did not undergo this modified Schmidt reaction under these conditions. The conversion of aromatic acids to N-substituted trifluoroacetamides is discussed and evidence is presented for the mechanism.
A STUDY OF SOME REACTIONS OF THE CYCLOPENTYL RADICAL
Authors: Gordon Alvin S.
Published: May 2006

The specific rate constant for opening the cyclopentyl radical has been determined to be 1014.5 exp –37 700/RT s−1. The energy of activation indicates that any eclipsed pairs of H atoms in the cyclic radical are not de-eclipsed in the activated complex. No evidence for the resulting five-membered linear radical can be found, only evidence for its breakdown products, allyl radical and ethylene.The disproportionation/combination ratio for methyl and cyclopentyl radicals is about 0.3. The energy of activation for methyl abstracting a hydrogen atom from cyclopentane has been confirmed as about 9.5 kcal/mole.Cyclopentyl radical also loses a hydrogen atom to form cyclopentene. The kinetic parameters are difficult to obtain because of radical–radical reactions which form cyclopentene. An analysis of the results indicates an energy of activation at least equal to that for opening the cyclopentyl ring.Evidence is presented to support the view that the cyclopentyl radical loses a molecule of hydrogen to form the resonance-stablized cyclopentenyl radical with an energy of activation close to that for opening the ring, and a pre-exponential factor about 1/10 of that for the opening of the ring.
CARBON-13 ISOTOPE EFFECTS IN SYSTEMS CONTAINING CARBON DIOXIDE, BICARBONATE, CARBONATE, AND METAL IONS
Authors: Thode H. G. , Shima M. , Rees C. E. , Krishnamurty K. V.
Published: May 2006

The fractionation of 13C between CO2(g) and CO3−--HCO3−(aq) in solution has been studied in single stage experiments using carbonic anhydrase to catalyze the hydration of CO2. Added metal ions, pH of the equilibrium mixture, and temperature are found to play important roles in the overall fractionation process. Theoretical evaluation of the 13CO2(g)--12CO3−(aq) equilibrium constant (K2) has been made using the most recent spectroscopic data on the exchanging species. The variation of the equilibrium constant K2 with temperature has been calculated for each 25 deg interval from 0 to 975 °C with the help of the McMaster University IBM 7040 computer. It is shown that the overall 13C fractionation in the system may be treated as contributions due mainly to three exchange equilibria whereby 13CO2(g) independently exchanges with 12CO2(aq), H12CO3(aq),and 12CO3−(aq), the corresponding equilibrium constants being K0, K1, and K2 respectively. The best fit values for the equilibrium constants are K0 = 1.0009, K1 = 1.0077, and K2 ≥ 1.013, indicating the order K0 < K1 < K2.
THE REACTIVITY OF THE CYCLIC POLYENES TOWARDS FREE RADICALS: II. METATHESIS WITH THE ETHYL RADICAL
Authors: Brown A. C. R. , James D. G. L.
Published: May 2006

Arrhenius parameters have been measured for metathesis between the ethyl radical and certain cyclic polyenes, chosen to reveal the extent to which particular structural features in a cyclic molecule may influence its reactivity towards metathesis. The highest reactivity was observed in cyclohexadiene-1,4 and is associated with the greatest increase in the delocalization of the π-electron system, which is only slightly offset by a minor change in the conformation of the carbon ring. Intermediate reactivity was displayed by the conjugated molecules cyclohexadiene-1,3 and cycloheptatriene, whereas cyclooctatetraene, which possesses no methylenic hydrogen atoms, was much less reactive. Very low reactivity was found in bicyclo[2.2.1]heptadiene-2,5; this molecule possesses the carbon ring structure of cyclohexadiene-1,4 symmetrically bridged by a methylene group, and the constraint imposed by this bridge upon the geometry of the ring appears to limit the reactivity of the molecule decisively.The ratio of the rate constants for disproportionation and combination between the cyclo-hexadienyl radical and the ethyl radical is kd/kc = 0.38 ± 0.03. The nature of the interaction between these two radicals is discussed, and the significance of this ratio is considered.
NUCLEOPHILIC ADDITION OF TRIETHYLAMINE TO DIMETHYL ACETYLENEDICARBOXYLATE
Authors: Alaimo Robert J. , Farnum Donald G.
Published: May 2006

not available
REACTION OF ARALKYL KETONE OXIMES WITH CARBON MONOXIDE AND HYDROGEN TO YIELD FORMAMIDES AND SECONDARY AMINES
Authors: Rosenthal Alex , Yalpani M.
Published: May 2006

not available
COMPLEX FORMATION BETWEEN PROPARGYL CHLORIDE AND BENZENE
Authors: Tyrrell James
Published: May 2006

The proton resonance signals of the methylene and ethynyl hydrogens in propargyl chloride shift upfield in going from cyclohexane to benzene as solvent. This is interpreted as being due to complex formation between propargyl chloride and benzene. Though the methylene proton resonance signal shifts farther upfield than does the ethynyl proton resonance signal, it is found that only a 1:1 complex exists between the two molecules. The complex is considered to be one in which the methylene protons "bond" to the π-electron system of the benzene ring. The ethynyl proton of the propargyl chloride is thought to lie close enough to the ring to interact with the "ring current", but not close enough to be a prime agent in complex formation.
DETERMINATION OF THE FIELD DEPENDENCE OF THE TAFEL SLOPE FOR THE STEADY-STATE ANODIC OXIDATION OF ALUMINIUM
Authors: Dignam M. J. , Goad D. , Sole M.
Published: May 2006

A novel and sensitive experimental technique has been developed and employed to measure the field variation of the Tafel slope at 25 °C for the steady-state anodic oxidation of aluminium. The data have been fitted to an equation of the form I = α exp [γE − δE2] where I and E are the current density and field strength in the anodic film and α, γ, and δ are positive constants for isothermal conditions. Some information concerning the field variation of the interfacial potentials has also been obtained.
AN EXOCELLULAR MANNAN, ALTERNATELY LINKED 1,3-β AND 1,4-β FROM RHODOTORULA GLUTINIS
Authors: Gorin P. A. J. , Horitsu K. , Spencer J. F. T.
Published: May 2006

The yeast, Rhodotorula glutinis, gives an exocellular mannan containing 1,3-β- and 1.4-β-D-mannopyranose residues arranged in a straight chain of at least 90 units. Consecutive 1,3-β links are absent and although consecutive 1,4-β links may exist they are present at most in only a very small proportion. The 1,3-β- and 1,4-β-D-mannopyranose residues are therefore arranged alternately in the chain.Mannans from R. mucilaginosa, R. minuta, and an unidentified Rhodotorula spp. 62-506 appear to have similar structures.
THE OXIDATION OF SUGAR ACETALS AND THIOACETALS BY ACETOBACTER SUBOXYDANS
Authors: Williams D. T. , Jones J. K. N. , Dennis N. J. , Ferrier R. J. , Overend W. G.
Published: May 2006

The oxidation by Acetobacter suboxydans of several aldose dimethylacetals and diethyldithioacetals has been achieved. Isolation and characterization of the ketose products showed that the oxidations had followed the Bertrand–Hudson rules.
AN IMPROVED SYNTHESIS OF ε-N-ACETYL-L-LYSINE AND SIMILAR COMPOUNDS
Authors: Benoiton Leo , Leclerc Jean
Published: May 2006

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

not available
THE CHEMISTRY OF SINGLET AND TRIPLET METHYLENE
Authors: Bader R. F. W. , Generosa John I.
Published: May 2006

Results are reported for the photolysis of small, fixed amounts of diazomethane and cis-butene-2 in the presence of increasing pressures of the inert gases He, Ar, Xe, N2, and CF4. The variation in the percentage yield of the trans-dimethylcyclopropane as a function of the inert gas pressure indicates that two basic mechanisms, with opposite dependencies on the inert gas pressure, are responsible for its formation. An initial decrease in the percentage yield of this trans isomer with increasing pressure indicates that a source is an isomerization of energized molecules. These excited molecules result from the addition of methylene in a singlet state to cis-butene-2. A subsequent rise in the yield of the trans isomer with further increases in the pressure indicates that another mechanism, one whose rate is increased by an increase in pressure, must be present. This is attributed to a mechanism involving triplet methylene. The pressure regions for the observation of the singlet or triplet behavior of methylene are thus known and the modes of formation of the other C5 products may be determined.
COMPLEXES OF BORON TRIFLUORIDE WITH FLUOBORATES
Authors: Brownstein S. , Paasivirta J.
Published: May 2006

The occurrence of complexes of boron trifluoride with some fluoborates has been established. Enthalpies of formation were determined for some of these complexes. Infrared and fluorine resonance spectra were obtained in an attempt to elucidate the structures of the complexes.
THE STEREOCHEMISTRY OF HALOGEN DISPLACEMENT BY NITRATE ION RACEMIZATION AND RETENTION OF CONFIGURATION IN THE SYNTHESIS OF DINITRATE ESTERS
Authors: Hayward L. D. , Jackson M. , Csizmadia I. G.
Published: May 2006

The reaction of silver nitrate in dry acetonitrile with 2,5-dideoxy-2,5-diiodo-1,4;3,6-dianhydro-L-iditol resulted in formation of the dinitrate esters of the 1,4;3,6-dianhydrides of D-mannitol, D-glucitol, and L-iditol. Similarly both endo- and exo-nitrato groups were introduced in displacement of the endo-halogen in the 2-deoxy-2-iodo-5-O-acetyl and 2-deoxy-2-iodo-5-O-p-toluenesulfonyl derivatives of 1,4;3,6-dianhydro-L-iditol. Since both types of nitrato groups were stable to silver nitrate, the racemization occurred during the displacement and was attributed to formation of cyclic carbonium ion intermediates. The steric effect of the adjacent ring in the carbonium ions apparently suppressed the termolecular, ion-pair mechanism previously established for the metathesis of acyclic alkyl halides and caused preferential formation of the exo-nitrato derivatives.The heterogeneous reaction of meso-dibromostilbene with silver nitrate in acetic acid or acetonitrile gave meso-dihydrobenzoin dinitrate with overall retention of configuration. This result could be most readily reconciled with the contrasting sequence of retention and inversion previously reported for meso- and dl-2,3-dibromobutane if participation of neighboring phenyl groups occurred in the second displacement step.
ALIPHATIC VICINAL FLUOROBROMIDES SOME PREPARATIONS AND REACTIONS
Authors: Pattison F. L. M. , Peters D. A. V. , Dean F. H.
Published: May 2006

The addition of "BrF", using N-bromoamides in anhydrous hydrogen fluoride, to a number of aliphatic alkenes has been studied. As expected, the bromine atom in the resultant vicinal fluorobromides exhibited relatively low reactivity in nucleophilic and hydrogenolytic reactions.
THE SYNTHESIS OF α-MONOFLUOROALKANOIC ACIDS
Authors: Pattison F. L. M. , Buchanan R. L. , Dean F. H.
Published: May 2006

α-Monofluoroalkanoic acids are important intermediates in the synthesis of biologically active fluorine compounds. General methods of preparation have been examined, based on the three following reagents: (a) hydrogen fluoride + N-bromoacetamide; (b) diethyl monofluoromalonate; and (c) perchloryl fluoride. The first of these is the recommended procedure for simple unsubstituted α-fluoro acids; however, the fluoromalonate route is less vigorous, and is therefore the method of choice for those α-fluoro acids that contain labile functional groups.
CONDUCTANCES AND SURFACE TENSIONS OF AQUEOUS SOLUTIONS OF SODIUM DECANOATE, SODIUM LAURATE, AND SODIUM MYRISTATE, AT 25° AND 35°
Authors: Campbell A. N. , Lakshminarayanan G. R.
Published: May 2006

The equivalent conductances of aqueous solutions of sodium decanoate, sodium laurate, and sodium myristate have been determined from the very dilute region up to saturation concentration, at 25° and 35°. The limiting conductances have been obtained from the measurements in the usual way. In addition and for the sake of completeness, the limiting equivalent conductances of sodium formate, sodium acetate, sodium propionate, and sodium butyrate have also been determined at 35°, since they were not known at this temperature.The effect of increasing chain length on mobility is discussed. From a consideration of the experimental and the theoretical values of the slopes of the plots of equivalent conductance against the square root of the concentration, it is concluded that some sort of interaction, possibly a reversible dimerization of anions, occurs, even in the dilute region, and this could account for the lower experimental values of the slope. This phenomenon has been observed with other long chain electrolytes, however, and the hypothesis of dimerization is not the only possible one.The critical micelle concentrations have been determined, and recent concepts of micelle formation are applied to interpret their structure. The surface tensions of the aqueous solutions have been measured at 25° and 50°.