bluuebunny/crossref_metadata_2025 huggingface dataset:
SOME DEUTERIUM KINETIC ISOTOPE EFFECTS: IV. β-DEUTERIUM EFFECTS IN WATER SOLVOLYSIS OF ETHYL, ISOPROPYL, AND tert-BUTYL COMPOUNDS
Authors: Leffek K. T. , Llewellyn J. A. , Robertson R. E.
Published: May 2006

The secondary β-deuterium isotope effects have been measured in the water solvolytic reaction of alkyl halides and sulphonates for primary, secondary, and tertiary species. In every case the kinetic isotope effect was greater than unity (kH/kD > 1). This isotope effect may be associated with varying degrees of hyperconjugation or altered non-bonding intramolecular forces. The experiments make it difficult to decide which effect is most important.
HYDROGENOLYSIS OF CARBOHYDRATES: IX. FORMATION OF 2,6-ANHYDRO-β-D-FRUCTOFURANOSE AND ETHYL α- AND β-D-FRUCTOFURANOSIDE FROM SUCROSE
Authors: Goldschmid H. R. , Perlin A. S.
Published: May 2006

A compound formed during the hydrogenolysis of sucrose in ethanol or dioxane at 180 °C, in the presence of copper chromium oxide catalyst, has been characterized as 2,6-anhydro-β-D-fructofuranose (2,5-anhydro-α-D-fructopyranose), a new type of anhydro-ketose. Ethyl α- and β-D-fructofuranosides are also produced when the hydrogenolysis reaction is carried out in ethanol, and various derivatives of these anomeric ketosides have been prepared.
DECOMPOSITION PRESSURES OF FERRIC SULPHATE AND ALUMINUM SULPHATE
Authors: Warner N. A. , Ingraham T. R.
Published: May 2006

The gas pressures over samples of anhydrous ferric sulphate and anhydrous aluminum sulphate have been measured in a static system, using a mercury manometer in which the exposed surface was covered with a flexible Pyrex bellows. The calculated ΔH for the decomposition of Fe2(SO4)3 was +135.4 kcal/mole. It was not possible to calculate the ΔH for the Al2(SO4)3 decomposition, because a discrete aluminum oxide with singular thermodynamic properties was not obtained.In the Fe2(SO4)3 system, the fraction of SO3 in the gas phase was found to be almost constant over the range of temperature and pressure changes used in the study.At any given temperature, the decomposition pressure over a ferric sulphate sample is greater than that over an aluminum sulphate sample, thus indicating that preferential decomposition of ferric sulphate should be thermodynamically feasible in mixtures of ferric sulphate and aluminum sulphate.
STUDIES ON IONIC SOLVATION: PART III. NEW THEORY FOR CALCULATING HEATS OF HYDRATION OF MONOVALENT IONS AT 25 °C
Authors: Azzam A. M.
Published: May 2006

From Part I of this series, the structure of solution around a completely hydrated monovalent ion could be visualized. On the basis of this picture, the ionic heats of hydration is to be due to three terms. These three terms are critically discussed and evaluated for the case of alkali metals and halide ions.The present theory shows that the Born–Bjerrum term contributes a significant part to the heat and that the ionic radius value included in this term must be dependent only on the charge and not on the ionic size. The most probable value is 2.4 Å for the positive ions and 2.9 Å for the negative ions.The calculated ionic heats of hydration, which are in good agreement with the experimental values, are compared with those of previous theories.
THE ROLE OF REACTION PRODUCTS IN THE SILVER-CATALYZED OXIDATION OF ETHYLENE
Authors: Hayes Kenneth E.
Published: May 2006

Initial-rate studies of the kinetics of the silver-catalyzed oxidation of ethylene oxide and carbon dioxide in a flow system have been made. It was found that, using carefully purified reactants, the effect of added carbon dioxide was to suppress the formation of ethylene oxide only. The initial rate of the formation of ethylene oxide is given by the equation[Formula: see text]where r0 is the initial rate in the absence of CO2; m, n, and k are constants with m + n = 1.These results together with the results of oxygen exchange reactions between O18 and C2H4O16, CO216 and H2O16 are interpreted mechanistically.
THE SEPARATION OF SUGARS ON ION-EXCHANGE RESINS. PART I. SEPARATION OF OLIGOSACCHARIDES
Authors: Jones J. K. N. , Wall R. A. , Pittet A. O.
Published: May 2006

Fractionation according to molecular size has been achieved by development of oligosaccharide mixtures with water on columns of neutral salt forms of sulphonic acid type ion-exchange resins. The method was used to separate a synthetic mixture of raffinose, sucrose, and glucose and a number of hydrolyzates of polysaccharides to give clean, salt-free fractions of high purity. The procedure is rapid and economical and provides a useful extension of older methods of separating such mixtures.
THE SEPARATION OF SUGARS ON ION-EXCHANGE RESINS: PART II. SEPARATION OF MONOSACCHARIDES
Authors: Jones J. K. N. , Wall R. A.
Published: May 2006

Columns of neutral salt forms of sulphonic acid type ion-exchange resins have been shown to be useful in separations of monosaccharide mixtures with water as the developing solvent. A number of synthetic mixtures and a series of plant extracts have been resolved into clean, salt-free fractions by use of the new technique. The procedure is analogous to column partition chromatography, but in many cases it is more rapid and gives a useful extension of separability.
THE NATURE OF POLYMERIZATION CATALYSTS PREPARED FROM METAL ALKYLS AND TITANIUM HALIDES
Authors: Jones M. H. , Martius U. , Thorne M. P.
Published: May 2006

A study has been made of the composition and structure of the insoluble complexes formed in the reaction of aluminum triisobutyl or lithium n-butyl with titanium tetrachloride or trichloride in heptane at room temperature by chemical and X-ray diffraction analyses. For the tetrachloride systems it has been shown that, with metal alkyl:titanium tetrachloride ratios of 0.5 to 4, at least 50% of the titanium is present in the tetravalent state and that there is considerable loss of chlorine and alkyl groups. The aluminum complexes are amorphous except at component ratios of 0.5 to 1, where the X-ray pattern indicated traces of titanium trichloride.With the aluminum triisobutyl–titanium trichloride system, X-ray evidence has shown that the titanium trichloride remains essentially unchanged. This result, together with the low aluminum content (less than 0.5%), is consistent with Natta's suggestion that this catalyst for define polymerization consists of a trichloride surface on which small quantities of aluminum alkyl are chemisorbed.The reaction between lithium butyl and titanium trichloride at ratios above unity results in the formation of a new crystalline compound having a sodium chloride type lattice with a lattice spacing of 5.20 Å. The compound is thought to be a double salt of the type (LiCl)n.TiCl2 or (LiCl)n.TiCl. Evidence of a second crystalline component was also noted but it could not be identified.Tentative reaction schemes are proposed for the formation of the various complexes and their structures are considered in relation to their ability to polymerize 1-butene.
EXOTHERMIC REACTIONS DUE TO ANNEALING OF DEFECTS IN OXIDE LATTICES: STUDY OF THE DECOMPOSITION OF CARBONATES
Authors: Rao C. N. R. , Yoganarasimhan S. R. , Lewis M. P.
Published: May 2006

Small exothermic reaction peaks are observed in the differential thermal curves of carbonates. The heat evolution is probably due to the removal of internal crystal defects in the metastable oxide lattices.
CONSTITUTION OF AN ARABINOGALACTAN FROM MAPLE SAP
Authors: Adams G. A. , Bishop C. T.
Published: May 2006

An arabinogalactan [Formula: see text] has been isolated from maple sap in yields varying between 7.5 and 17.0 mg per 100 ml of sap. The polysaccharide was electrophoretically homogeneous and contained D-galactose, L-arabinose, and rhamnose in a molar ratio of 51:44:5. Methylation and hydrolysis of the polysaccharide yielded the following O-methyl ethers which were analyzed by gas–liquid partition chromatography: 2,3,5-tri-O-methyl-L-arabinose (4 moles); 2,5-di-O-methyl-L-arabinose (2 moles); 2,4-di-O-methyl-D-galactose (4 moles); 2,4,6-tri-O-methyl-D-galactose (7 moles); 2,3,4-tri-O-methyl-L-rhamnose (1 mole). A possible structure for the polysaccharide is proposed and discussed in relation to other arabinogalactans.
THE ORTON REARRANGEMENT IN APROTIC SOLVENTS. SOME OBSERVATIONS ON THE REACTIONS OF p-SUBSTITUTED N-BROMOACYLANILIDES IN CHLOROBENZENE AND TRICHLOROACETIC ACID
Authors: Scott J. M. W.
Published: May 2006

The qualitative and kinetic behavior of a series of p-substituted N-bromoacylanilides when treated with trichloroacetic acid in chlorobenzene has been studied. The abnormal reaction which was previously demonstrated for the o-nitro derivative has been shown to occur with the p-isomer. The mechanisms of the normal and abnormal reactions are discussed. Some derivatives of 4-fluoro-3-bromoaniline are described.
STRUCTURAL AND SOLVENT EFFECTS ON THE n → π*(′U ← ′A) TRANSITIONS IN ALIPHATIC CARBONYL DERIVATIVES: EVIDENCE FOR HYPERCONJUGATION IN THE ELECTRONICALLY EXCITED STATES OF MOLECULES
Authors: Rao C. N. R. , Goldman G. K. , Balasubramanian A.
Published: May 2006

The n → π* transition of the carbonyl group has been studied in solvents of varying degree of polarity and hydrogen-bonding ability, in a number of aliphatic carbonyl derivatives. Evidence for hyperconjugation of the alkyl groups in the electronically excited states of molecules has been presented.
INDOLYL-3-ACETALDOXIME
Authors: Ahmad A. , Eelnurme I. , Spenser Ian D.
Published: May 2006

not available
HYDROGEN ATOM ABSTRACTION BY ETHYL-d5 RADICALS. PART II
Authors: Boddy P. J. , Steacie E. W. R.
Published: May 2006

Further experiments are reported on the hydrogen atom abstraction reactions of deuterated ethyl radicals produced by the photolysis of 3-pentanone-d10.
DEUTERATED ORGANIC COMPOUNDS: XXII. SYNTHESIS OF SOME DEUTERATED BENZENE DERIVATIVES
Authors: Renaud R. N. , Kovachic D. , Leitch L. C.
Published: May 2006

The deamination of certain aromatic amines in deuterohypophosphorous acid with sodium or isoamyl nitrite has been used to label aromatic compounds in a specific position with deuterium. Aniline 2,3-d2 was synthesized by this method.
A PROTON MAGNETIC RESONANCE INVESTIGATION OF ROTATIONAL ISOMERISM IN 1,1,2,2-TETRACHLORO-1-FLUOROETHANE
Authors: Abraham R. J. , Bernstein H. J.
Published: May 2006

The doublet separation in the proton resonance spectrum of the liquid was measured from −53 to 100 °C. From the variation of the separation with temperature approximate values of the trans and gauche HF coupling constants were obtained. The values of ΔH ≈ 400 cal/mole and ΔS ≈ 0 are also consistent with the data.
THE DECOMPOSITION OF METHANE IN THE NEGATIVE GLOW
Authors: Tickner A. W.
Published: May 2006

The decomposition of methane was studied in the negative glow of a d-c. discharge at pressures of 0.30 and 0.050 mm. The discharge tube was cooled by liquid or solid nitrogen.The main products were ethane, ethylene, and acetylene in addition to hydrogen and a nonvolatile product which appeared mainly on the cathode as a solid having the formula (CH)n. Smaller amounts of propane, propene, propyne, butane, butene, butadiene, and pentene were also found. Lowering the temperature of the discharge tube from −196° to −210 °C greatly increased the amount of ethylene recovered.The solid product is apparently transported to the cathode in the form of ions and may result from ionic polymerization of the acetylene. Acetylene is the volatile product formed closest to the cathode which suggests that it may also be formed by ionic processes. The formation of the remaining products is consistent with an excitation mechanism in which the C2 products are formed first and the higher hydrocarbons are formed from them.
FREE RADICALS BY MASS SPECTROMETRY: XXII. PRIMARY DECOMPOSITION STEPS IN THE MERCURY-PHOTOSENSITIZED DECOMPOSITION OF METHANOL AND DIMETHYL ETHER
Authors: Pottie R. F. , Harrison, A. G. , Lossing F. P.
Published: May 2006

The Hg 3P1 photosensitized decomposition of methanol at low pressures proceeds mainly by a dissociation into CH3O radicals and H atoms. No formation of CH2OH radicals is observed. A subsidiary reaction to form CH3 and OH may also be a primary step. Formation of CH2OH radicals at higher pressures is attributed to an abstraction reaction of CH3O with CH3OH.Two primary modes of dissociation are found to occur for dimethyl ether:[Formula: see text]The relative probabilities of occurrence at low pressures are ∼45% and ∼50%, respectively. The possibility that the second reaction proceeds by formation of an excited molecule is discussed.
THE CONFIGURATION AND CONFORMATION OF THYMIDINE
Authors: Lemieux R. U.
Published: May 2006

The nuclear magnetic resonance spectrum for the anomer of the naturally occurring deoxyribonucleoside thymidine allowed a conclusion as to its anomeric configuration through an interpretation of the fine structure observed in the signals for the H1′, H2′, and H2″ atoms. Thus, indirect evidence for the configuration of thymidine was obtained. The nuclear magnetic resonance spectrum of thymidine suggests that the compound possesses considerable conformational purity when dissolved in water since an interpretation of the spectrum leads to the assignment of the plausible conformation wherein all of the large substituents on the furanose ring are in partially staggered orientations with the neighboring atoms.
PERFLUOROALKYL DERIVATIVES OF TIN: II. DIMETHYLTRIFLUOROMETHYLTIN CHLORIDE
Authors: Chambers R. D. , Clark H. C. , Willis C. J.
Published: May 2006

A methyl group is cleaved by chlorine in preference to trifluoromethyl from trimethyltrifluoromethyltin and dimethyltrifluoromethyltin chloride; the significance of this is discussed in terms of the electronegativity of the trifluoromethyl group. The influence of trifluoromethyl on the acceptor properties of the tin atom in dimethyltrifluoromethyltin chloride has been illustrated by means of conductivity measurements. Nuclear magnetic resonance measurements of trimethyltrifluoromethyltin and dimethyltrifluoromethyltin chloride are also reported.
CONTRIBUTION À L'ÉTUDE DE A RÉACTION DE VON RICHTER: I. SUR L'IDENTIFICATION DE QUELQUES PRODUITS ACIDES
Authors: Cullen E. , L'Écuyer Ph.
Published: May 2006

not available
THE PREPARATION, PAPER CHROMATOGRAPHY, AND COLOR REACTIONS OF SEVERAL 5,6-DIHYDROXYINDOLES AND 5,6-DIACETOXYINDOLES
Authors: Heacock R. A. , Mahon M. E. , Scott B. D.
Published: May 2006

The paper chromatographic behavior of several 5,6-dihydroxyindoles has been studied. The colors given by nine dihydroxyindoles with 16 chromogenic reagents are reported. The Rfvalues of this group of compounds on Whatman No. 1 paper with 2% acetic acid in water or n-butanol/acetic acid/water (6:1:2) as running solvents have been determined. The 5,6-dihydroxyindoles can be chromatographed satisfactorily using Zaffaroni-type systems (i.e. formamide-treated paper and non-polar running solvents). Satisfactory Rfvalues can also be obtained for the 5,6-diacetoxyindoles on formamide-treated paper using a suitable non-polar mobile phase. The preparations of several new 5,6-dihydroxyindoles and 5,6-diacetoxyindoles are described and improved procedures for the syntheses of some known members of these groups are reported.
CHARACTERISTIC VIBRATIONS OF THE SULPHURYL GROUP
Authors: Robinson E. A.
Published: May 2006

A compilation of the S—O symmetric and asymmetric stretching frequencies is given for a large number of compounds containing an —SO2— group. It is shown that a linear relationship between [Formula: see text] is valid for a large number of sulphuryl and polysulphuryl compounds and that the actual frequencies depend in a systematic manner on the electronegativities of the attached groups. These relationships have proved very useful in assigning and in some cases reassigning the S—O bands in the infrared and Raman spectra of a number of sulphuryl compounds. It is pointed out that there is a relationship between the SO2 frequencies of some sulphonic acids and their acid strengths.The calculation of values for group electronegativities from the vibration frequencies of the P=O and SO2 groups is discussed.
INFLUENCE OF pH AND TEMPERATURE ON MYOSIN INACTIVATION
Authors: Pelletier Gérard E. , Ouellet Ludovic
Published: May 2006

The inactivation of myosin adenosine triphosphatase activity was studied in 0.6 M potassium chloride solution at pH ranging from 7.0 to 10.8 and for 5 °C to 40 °C. The inactivation is a first-order process with respect to time and 0.6th order with respect to the concentration of protein. The rate of inactivation is independent of the pH for pH 7.0 to pH 8.5 at 35 °C and increases rapidly with pH at higher pH. At 12 °C, close to pH 10.4, the rate is inversely proportional to the 4.5th power of the hydrogen ion concentration. The energies of activation are 56 kcal mole−1at pH 8.0 and 58 kcal mole−1at pH 10.5. A discussion of the data stresses the importance of structural changes and indicates a possible role for the electrostatic charge in the inactivation process.
RATES OF DECARBOXYLATION OF SUBSTITUTED ANTHRANILIC ACIDS IN NITROBENZENE SOLUTION
Authors: Dunn G. E. , Prysiazniuk Russell
Published: May 2006

The synthesis of a series of meta- and para-substituted anthranilic acids is reported with their rates of decarboxylation in nitrobenzene solution at 210.5 °C. The reaction is second order with respect to anthranilic acid. The rate is increased by electron-releasing substituents and decreased by deuterium in the functional groups. The relative rates are interpreted by means of the Hammett equation and its extensions and it is concluded that the rate-determining step involves attack by proton from one anthranilic acid molecule on carbon 1 of a second molecule.
CHALKOGENIDES OF THE TRANSITION ELEMENTS: II. EXISTENCE OF THE π PHASE IN THE M9S8 SECTION OF THE SYSTEM Fe–Co–Ni–S
Authors: Knop Osvald , Ibrahim Mohammad Anwar
Published: May 2006

The face-centered cubic phase π(Fe,Co,Ni,S) has been shown to exist, at room temperature, within wide composition limits in or close to the M9S8 section of the quaternary system Fe–Co–Ni–S. The M:S ratio of the binary phase π (Co,S) is 9:8 with very narrow homogeneity ranges on both sides of Co9S8, but in π (Fe,Co,Ni,S) the ratio is somewhat higher and appears to increase with decreasing cobalt content. Stoichiometric Co9S8 probably contains a small number of vacancies in both sublattices. It is quite lilcely that the sulphur sublattice is nearly fully occupied and that departures from stoichiometry are caused by the varying degree of occupancy of the metal sublattice.The crystal structure, which was proposed for Co9S8 and for the mineral pentlandite by Lindqvist etal., has been confirmed for these two substances and for π (Fe,Co,Ni,S) in general by X-ray and neutron powder diffraction. The present evidence does not support the crystal structure suggested for natural pentlandite by Eliseev; Eliseev's model does not, in fact, account for the diffraction data of any of the substances examined in this work.Replacement of cobalt in π (Co,S) by iron or nickel or both results in an expansion of the unit cell, the maximum increase in a(π) amounting to about 3%. Cobalt in π (Co,S) cannot be replaced completely by iron or by nickel in samples prepared by dry synthesis, but if the substitution is simultaneous, the π structure will be preserved over a considerable range of compositions even on total replacement. The stability limits of π (Fe,Ni,S) have been found somewhat wider than those stated by Lundqvist.In π phases with the compositions Co8MS8 the metal atoms can conceivably be present in ordered sublattices. This possibility was explored by neutron diffraction in slowly cooled Co8NiS8. Unlike in spinels, where nickel shows a strong preference for octahedral co-ordination, the cobalt and nickel atoms were found to be distributed at random.
PHASE TRANSITIONS IN SOME ANHYDROUS POTASSIUM SOAPS
Authors: Grant R. F. , Dunell B. A.
Published: May 2006

The proton magnetic resonance absorption of the anhydrous potassium soaps of palmitic, myristic, lauric, and capric acids has been studied. Pronounced changes in the proton magnetic resonance line widths correspond to known phase transitions in these soaps.
THE CRYSTAL SPECTRUM OF PERYLENE
Authors: Hochstrasser Robin M.
Published: May 2006

The electronic absorption spectrum of crystalline perylene has been examined in the spectral region 3000–4700 Å. The lowest energy electronic state of perylene has a large oscillator strength and the crystal spectrum deviates considerably from that calculated from a weak coupling (Davydov) model.The sublimation flakes were examined at room temperature and at the temperature of boiling nitrogen. The lowest energy crystal state was polarized along the crystallographic a-axis (Bu) and the factor group splitting of lowest vibrational envelope of the electronic band was 800 cm−1. The whole spectrum was more intense along the a- than along the b-axis of the crystal. These results are consistent with the notion that the crystal spectrum is derived from dipole-induced dipole interactions between molecular B2u levels of perylene and neighboring unexcited molecules. This assignment of the lowest excited level of perylene is in agreement with theory.The molecular vibrational structure is severely altered in the crystal and the observed crystal shift is much smaller than that predicted by the Davydov theory.
THE EFFECT OF INTRAMOLECULAR TWISTING ON THE EMISSION SPECTRA OF HINDERED AROMATIC MOLECULES: PART I. 1,1′-BINAPHTHYL
Authors: Hochstrasser Robin M.
Published: May 2006

The fluorescence spectrum of 1,1′-binaphthyl has been examined in solution, in rigid glass, and in the crystal. It is found that in rigid media the spectral location of the emission is very sensitive to temperature. At 300 °K the band is broad and structureless with a maximum at 26,700 cm−1 and a zero–zero band at about 30,200 cm−1 with very low intensity. The same is true at 273 °K and 195 °K. At temperatures below 157 °K structure starts to appear until at 77 °K the center of gravity of the emission is around 29,000 cm−1 and the 0–0 band at 31,270 cm−1 is quite clear and strong. Even at 77 °K there is apparent a broad, but now weak band at 27,260 cm−1. In the crystal the spectrum is broad and structureless at 300 °K with a maximum emission intensity at 26,300 cm−1. On lowering the temperature to about 142 °K the intensity is built up on the high energy side of this band until eventually a new peak at 27,850 cm−1 becomes apparent at 77 °K.These results are interpreted on the basis of unsymmetrical potential energy variations with angle of twist which permit two origins for the fluorescence spectra of double molecules of this type.
NITRO- AND AMINO-IMIDAZOLESULPHONAMIDES
Authors: Fisher M. H. , Nicholson W. H. , Stuart R. S.
Published: May 2006

Several 4(5)-nitro- and 4(5)-amino-5(4)-sulphamylimidazoles have been synthesized as potential antagonists to 4(5)amino-5(4)-carbamylimidazole.
SPECTROPHOTOMETRIC STUDY OF THE REACTION BETWEEN IRON (III) AND KOJIC ACID
Authors: McBryde W. A. E. , Atkinson G. F.
Published: May 2006

A method introduced by Vareille enables calculation of formation constants of colored metallic complexes in solution by making appropriate deductions from the presence of isobestic points in the spectra of suitably chosen solutions. The rationale of this method is derived rigorously, and its application extended to include cases where three complexes are present together in certain regions of pH. These principles are applied to derive for the ferric kojates the following formation constants, at 25 °C and ionic strength 0.5: log K1 = 10.16, log K2 = 8.29, log K3 = 6.90. The relationship between pH and pL for the experimental conditions is calculated, thereby enabling the estimation of the distribution of the metal among the several species in each solution and the absorption spectrum of each complex.
THE COMPLEX DIELECTRIC CONSTANT OF SOLUTIONS OF TRIMETHYLPENTANE AND NITROBENZENE NEAR THE CONSOLUTE TEMPERATURE
Authors: Ripley B. D. , McIntosh R.
Published: May 2006

The complex dielectric constants of three compositions of trimethylpentane and nitrobenzene have been measured as a function of temperature for a range near the consolute temperature. The frequency employed was 3300 Mc/sec. The experimental procedure involved the study of the standing wave established in a coaxial line. The chemical systems showed maxima in both the real and imaginary parts of the complex dielectric constant at temperatures above those at which phase separation occurs. The finding of Semenchenko and Azimov is thus confirmed. A discussion of the validity of applying thermodynamic formulae to dielectrics showing loss is given and some qualitative remarks are offered concerning the change of the systems as they are cooled. These remarks are based upon the effect of the applied field upon the entropy of the solutions.
CHEMISTRY OF THE TRIFLUOROMETHYL GROUP: PART III. PHENYLBISTRIFLUOROMETHYLPHOSPHINE AND RELATED COMPOUNDS
Authors: Beg M. A. A. , Clark H. C.
Published: May 2006

The reaction of trifluoroiodomethane with tetraphenylcyclotetraphosphine leads to the formation of phenylbistrifluoromethylphosphine and phenyltrifluoromethyliodophosphine. The mechanism of the reaction is discussed and the physical and chemical properties of these compounds are reported. Bromine reacts with phenylbistrifluoromethylphosphine to form phenylbistrifluoromethyldibromophosphorane which is hvdrolyzed to phenyltrifluoromethylphosphinic acid, C6H5(CF3)P(O)OH.
DIELECTRIC RELAXATION IN LIQUIDS: I. THE REPRESENTATION OF RELAXATION BEHAVIOR
Authors: Davidson D. W.
Published: May 2006

Methods are described for the determination from experimental data of the parameters used in the skewed-arc representation in the complex dielectric constant plane of dielectric relaxation in liquids. Graphs give the frequency dependence of the real and imaginary parts of the dielectric constant predicted by the skewed-arc equation. Evidence, which includes an analysis of published data and of some new data, is presented for the frequent occurrence of this type of relaxation behavior in liquids. The resolution of the effects of different relaxation processes is discussed.The recent defect-diffusion model of Glarum is found to lead, under some conditions, to complex dielectric constant loci which are practically indistinguishable from skewed-arc loci over much of the frequency range of dispersion. It predicts departures from skewed-arc behavior at relatively high frequencies which are possibly related to experimentally observed departures.It is concluded that skewed-arc characteristics arise from the presence of co-operative relaxation processes, possibly aided by the diffusion of disordered regions, in which the individual mechanisms of relaxation cannot be resolved by application of the superposition principle.
Th232 (n,2n)Th231 CROSS SECTION FROM THRESHOLD TO 20.4 MEV
Authors: Butler J. P. , Santry D. C.
Published: May 2006

The excitation curve for the reaction Th232 (n,2n) Th231 has been measured by the activation method from the threshold energy, 6.34 Mev, to 20.4 Mev, relative to the known cross section for the S32 (n,p)P32 reaction. Monoenergetic neutrons were obtained from the D (d,n) He3 and T (d,n) He4 reactions employing a Tandem Van de Graaff accelerator. From threshold to 9.0 Mev, the (n,2n) cross section rises rapidly, reaching its maximum value of 1.88 ± 0.09 barns in the region of 9.5 to 11.0 Mev. Above 11.5 Mev the (n,2n) cross section decreases due to competition of the (n,3n) and (n,2nf) reactions and at 20.4 Mev it has a value of 0.225 ± 0.015 barns.
FURTHER STUDIES ON THE REACTION BETWEEN HALOGEN-SUBSTITUTED NITRILES AND AMINES
Authors: Grivas John C. , Taurins Alfred
Published: May 2006

The scope of the reaction of halogen-substituted nitriles and amines was extended by including trifluoro- and dichloro-acetonitrile. Trifluoroacetonitrile reacts easily with primary and secondary aliphatic, primary aromatic, and heterocyclic amines to give the corresponding amidines. N-Mono- and N-di-substituted dichloroacetamidines were prepared from dichloro-acetonitrile and amines, Trichloroacetonitrile also affords N-substituted amidines with heterocyclic amines.
THE ABSORPTION SPECTRUM OF DIPHENYLENE IN THE NEAR-ULTRAVIOLET
Authors: Hochstrasser Robin M.
Published: May 2006

The absorption spectrum of diphenylene has been measured in the vapor at a variety of temperatures, in solution at room temperature, and in an EPA rigid glass at 90 °K. From a consideration of the band structure and intensity distribution it was concluded that the weak absorption at 25,041 cm−1 (vapor; ƒ ≈ 10−3) is due to a symmetry-forbidden electronic transition. The theoretical prediction that the excited level is of species B1g was supported by the presence of a strong infrared band at 732 cm−1 corresponding to observed perturbing vibration of frequency 792 cm−1. The solution spectrum was found to exhibit a vibrational structure typical of a g–g forbidden excitation.
COUPLING CONSTANTS IN RIGID FIVE-MEMBERED RINGS: N.M.R. SPECTRA OF THE CAMPHANE-2,3-DIOLS
Authors: Anet F. A. L.
Published: May 2006

The proton nuclear magnetic resonance (N.M.R.) spectra of the four diastereoisomers of camphane-2,3-diol are reported. The coupling constants between the 2-, 3-, and 4-protons agree with the values predicted by Karplus for ethane derivatives. In particular, the cis (0° dihedral angle) coupling constants (7.7 and 8.9 c.p.s.) are much larger than the trans (120° dihedral angle) coupling constants (2.2 and 2.3 c.p.s.). Unexpected 1,3-coupling between exo-hydrogen atoms occurs in some of the compounds studied.
DEUTERATION OF FLUORENE AT C9 AND THE ASSIGNMENT OF CERTAIN BANDS IN THE INFRARED SPECTRUM TO THE AND GROUPS
Authors: Scherf G. W. H. , Brown R. K.
Published: May 2006

Equimolar amounts of 9-fluorenylpotassium and deuterium oxide, or potassium deuteroxide and fluorene, or potassium hydroxide, fluorene, and deuterium oxide gave a mixture of unchanged fluorene, 9-deuterofluorene, and 9,9-dideuterofluorene. In 1,2-dimethoxyethane (DME) deuteration occurs more readily and dideuteration is more extensive than in dioxane. Lithium deuteroxide and fluorene in DME show no exchange, but upon addition of deuterium oxide some monodeuteration occurs. 9-Fluorenyllithium and deuterium oxide in DME gives as much as 80% of 9-deuterofluorene accompanied by a small amount of dideuteration. Dideuteration is practically eliminated, and monodeuteration correspondingly increased when the same reaction is carried out in hexane.The bands at 667 cm−1, 827 cm−1, and 974 cm−1 have been assigned definitely to the[Formula: see text] group while those at 677 cm−1 and 832 cm−1 are due to the[Formula: see text] group in fluorene.
CONTRIBUTION À L'ÉTUDE DE LA RÉACTION DE VON RICHTER: IV. COMMENTAIRES CONCERNANT LA RÉACTION
Authors: Cullen E. , L'Écuyer Ph.
Published: May 2006

not available
CONSTITUTION OF A GLUCOMANNAN FROM TAMARACK (LARIX LARICINA)
Authors: Kooiman P. , Adams G. A.
Published: May 2006

A hemicellulose fraction containing D-mannose, D-glucose, and D-galactose in a ratio of 70:25:3 has been isolated from tamarack wood. The product was homogeneous under conditions of free boundary electrophoresis and of sedimentation in the ultracentrifuge. Hydrolysis of the fully methylated hemicellulose yielded 2,3,4,6-tetra-O-methyl-D-glucose (1.2%); 2,3,4,6-tetra-O-methyl-D-galactose (2.2%); 2,3,6-tri-O-methyl-D-glucose (24.0%); 2,3,6-tri-O-methyl-D-mannose (68.8%); 2,3-di-O-methyl-D-mannose (1.6%); and 2,3-di-O-methyl-D-glucose (1.7%). This data and that from periodate oxidation indicated that the glucomannan had a linear backbone of approximately 35 (1 → 4) linked β-D-glucopyranose and β-D-mannopyranose units; approximately two thirds of the chains were terminated at the non-reducing ends by D-galactose and the remainder by D-glucose. Branching, if present, must occur through C6 of the hexoses in the main chain.
THE ELECTRICAL CONDUCTIVITY OF LIQUID TIN: (II) SULPHIDE
Authors: Boutin Denis , Bourgon Marcel
Published: May 2006

The electrical conductivity "σ" of tin (II) sulphide in the liquid state has been measured using a capillary type cell. Both a-c. and d-c. methods were used. The conductivity of SnS increases regularly with temperature, from approximately 24 ohm−1 cm−1 at 895 °C to 31.2 ohm−1 cm−1 at 930 °C. The similarity of results obtained with both a-c. and d-c. methods, the positive temperature coefficient of conductivity, the high value of the conductivity and the absence of electrolysis effects when passing heavy currents in the melt lead to the conclusion that SnS remains a semiconductor in the liquid state. The value of the energy gap has been calculated to be 1.9 ev for the liquid as compared to the value 1.2 ev for the solid. Conductivity measurements have been limited to the temperature of approximately 935 °C because of the decomposition of SnS at higher temperatures.
THE EFFECT OF BETA-DECAY ON THE EXCHANGE PROPERTIES OF THE RARE EARTH–EDTA COMPLEX IONS
Authors: Glentworth P. , Betts R. H.
Published: May 2006

It is shown that the rare earth ion Yb3+ is very resistant towards ordinary thermal exchange when it is complexed with the chelating agent EDTA in aqueous solution. However, when the complexed rare earth atom, as the 1.8-h Yb-177, emits a beta-particle, the daughter atom Lu-177 escapes readily from the chelate structure. Nuclear recoil arising from the beta-particle emission is shown not to be the cause of the escape of the daughter atom. It is suggested that the observed lability of the daughter atom is a result of a high degree of chemical reactivity of the chelate ion arising from the sudden change in atomic number of the central metal ion of the chelate structure.
SOME STABLE DIMERS OF SUBSTITUTED BENZYLCYANAMIDES
Authors: Garmaise D. L. , Uchiyama A.
Published: May 2006

2,4- and 3,4-Dichlorobenzylcyanamides dimerize on standing to 1-cyano-1,3-di-(2,4-di-chlorobenzyl)-guanidine and 1-cyano-1,3-di-(3,4-dichlorobenzyl)-guanidine respectively. Apart from dicyandiamide itself, no other cyanamide dimers appear to have been described. The dinners on heating are converted into the corresponding trisubstituted isomelamines. 1-Cyano-1,3-di-(3,4-dichlorobenzyl)-guanidine condenses with 4-nitrobenzylcyanamide to form 1,3-di-(3,4-dichlorobenzyl)-5-(4-nitrobenzyl)-isomelamine. No dimers were obtained from the 4-chloro-, 4-bromo-, 4-nitro-, or 4-methyl-benzylcyanamides.
THE STRUCTURE AND RESISTANCE TO METHYLATION OF 1,2-β-GLUCANS FROM SPECIES OF AGROBACTERIA
Authors: Gorin P. A. J. , Spencer J. F. T. , Westlake D. W. S.
Published: May 2006

The structures of extracellular polysaccharides produced by the plant pathogens Agrobacterium tumefaciens (2 strains), A. rhizogenes, A. radiobacter, A. ruhi, A. gypsophilae, and A. pseudotsugae were investigated. Polymeric material was formed in good yield from all organisms except A. gypsophilae. Periodate oxidations of the polysaccharides and their sodium borohydride reduction products indicated linear 1,2-glucopyranose structures for A. tumefaciens (2 strains), A. rhizogenes, A. radiobacter, and A. rubi polymers. Optical rotational considerations led to the assignment of β-configurations. The linear structure for the A. radiobacter polysaccharide was confirmed by the isolation, after partial acid hydrolysis, of five 1,2-linked oligosaccharides with chain lengths of two to six. Periodate and chromatographic data indicated that the polysaccharide from A. pseudotsugae contained glucose and galactose and 1,6- as well as 1,2-glycopyranose links. It is noteworthy that the polysaccharides from the genus Agrobacteriurm are shown to be mainly 1,2-β-glucans, a structure not yet found in other genera.Treatment of linear 1,2-β-glucans from A. tumefaciens, A. radiobacter, and A. rhizogenes with sodium hydroxide – dimethyl sulphate, followed by silver oxide in methyl iodide dimethyl formamide, did not cause full methylation. Some of the 3-hydroxyl groups were not substituted and possible reasons for this unreactivity are discussed.
A STUDY OF THE CN EMISSION FROM ACTIVE NITROGEN FLAMES
Authors: Bayes Kyle D.
Published: May 2006

When organic compounds are added to active nitrogen, the red and violet bands of the CN radical are emitted. The relative intensities of these red bands have been measured for a variety of added compounds, temperatures, and pressures. It is shown that there are at least three processes producing electronically excited CN radicals, two yielding CN(A2II) and one yielding CN(B2∑). The behavior of the flames indicates that a chain mechanism is involved. Adding ammonia, which does not react with nitrogen atoms, quenches the CN emission and inhibits the consumption of nitrogen atoms. It is concluded that a second reactive species in active nitrogen, possibly metastable N2(A3∑) molecules, initiates the reactions which result in light emission.
PRESSURE EFFECT AND MECHANISM IN ACID CATALYSIS: VIII. HYDROLYSIS OF ACETAMIDE AND BENZAMIDE
Authors: Osborn A. R. , Mak T. C-W. , Whalley E.
Published: May 2006

The effect of pressures up to 3 kbar on the rate of the acid-catalyzed hydrolysis of acetamide and benzamide in both dilute and concentrated perchloric acid has been measured. The volumes of activation in dilute acid are consistent with a transition state that is not highly polar. It follows from this that if the attacking water molecule adds to the amidium ion then the reactive amidium ion is the O-protonated form, and if the attacking water molecule substitutes then the reactive amidium ion is the N-protonated form.The volume of activation for acetamide in concentrated acid provides no additional information about the mechanism. That for benzamide in concentrated acid is tentatively interpreted as favoring the O-protonated benzamidium ion as the reactive ion.
A NOTE ON THE PREPARATION OF SOME 1-PHENYL-2-NITROETHANOL DERIVATIVES
Authors: Heacock R. A. , Hutzinger O. , Nerenberg C.
Published: May 2006

not available
FINE STRUCTURE IN THE PROTON MAGNETIC RESONANCE SPECTRUM OF 6–6 NYLON
Authors: Shaw D. J. , Dunell B. A.
Published: May 2006

not available
STUDIES ON THE PERVANADIUM COMPLEX
Authors: Dean G. A.
Published: May 2006

The 'pervanadium complex' is investigated in a general manner. The kinetics of its thermal decomposition in acid solution are shown to be first order with respect to pervanadium, the apparent activation energy is 26.5 ± 1.0 kcal/mole, and possible mechanisms are suggested. The effect of various acids upon the nature of the decomposition products is determined: almost quantitative yields of vanadium (V) or vanadium (IV) are obtained in very dilute or concentrated acid, respectively. Spectrophotometric studies indicate that in acid solution two separate complexes exist: a red (1:1) cationic complex and a yellow (1:2) anionic complex. The stoichiometry of the equilibrium between the two complexes in solutions of sulphuric acid is investigated by a method of 'discrete variations'. The equilibrium could be described by[Formula: see text]where Kr/y = 2.2 ± 0.2 at 22 °C. The anion is shown to play an important part in determining the nature of the pervanadium complex.
INFRARED SPECTRA OF 2,6-DIMETHYL-4-PYRONE COMPLEXES
Authors: Cook Denys
Published: May 2006

The infrared spectra of 2,6-dimethyl-4-pyrone in solution, and in complexes with HgCl2, ZnCl2, BF3, SbCl5, and HBr have been recorded. A band at 1639 cm−1 in the free pyrone moves to progressively lower frequencies in the complexes as the Lewis acid strength increases, identifying this band as the carbonyl stretching frequency and the donor site as the carbonyl group. A higher-frequency band, at 1678 cm−1 in the free pyrone, moves to lower frequency on complex formation, but to a much smaller extent, and is to be identified with a stretching mode of the ring. The site of protonation in 2,6-dimethyl-4-pyrone salts has been unequivocally shown to be the carbonyl oxygen atom.
GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART III. THE USE OF OLEIC ACID ESTERS AS LIQUID PHASES
Authors: Rudloff E. von
Published: May 2006

The separation of several cyclic terpene hydrocarbons and some oxygenated derivatives was studied on a variety of triglyceride and dioleate ester columns. Use of rapeseed oil, partially hydrogenated rapeseed oil, olive oil, triolein, tristearin, methyl oleate, and potassium oleate as liquid phases led to the conclusion that the presence of an esterified mono-unsaturated long-chain acid is a desirable constituent of the liquid phase. Dioleate esters of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polyethylene glycol showed useful differences in the degree of separation of both terpene hydrocarbons and oxygenated derivatives. Ether linkages, as in the di- and poly-ethylene glycol ester, also were associated with favorable separations. When the liquid phase contained free hydroxyl groups, the degree of separation of hydrocarbons and ketones was in general less favorable. The spacing of the ester groups was found to have some effect on retention data. The separation of such critical pairs of isomers as tricyclene and α-pinene, α-fenchene and camphene, and also geometrical isomers of oxygenated derivatives is facilitated by use of several of these liquid phases.
THE HELLMANN–FEYNMAN THEOREM AND CHEMICAL BINDING
Authors: Bader Richard F. W. , Jones Glenys A.
Published: May 2006

The advantages of the electrostatic interpretation of chemical binding are illustrated. It is shown that the forces exerted by the electrons in a molecular orbital may be determined by general expressions. These are functions of only one parameter, the value of which is easily specified for a particular case. From the general expressions it is possible to obtain quantitative measures of the bonding or antibonding power of a molecular orbital. It is shown that the usual interpretations of bonding and antibonding properties in molecular orbital theory are misleading and that few orbitals are, in actual fact, antibonding. If molecular orbitals are classified as netbonding or netantibonding, terms which are precisely defined and have a definite physical significance, a much closer correlation with previous concepts of bonding is obtained. The effects of mutual orthogonalization within a set of orbitals are studied. It is found that this procedure decreases the bonding ability of bonding orbitals, but increases that of antibonding orbitals. The dangers of disregarding such orthogonalization in a conventional calculation are clearly illustrated.
π-BONDING IN INORGANIC COMPOUNDS: III. A MAGNETOCHEMICAL STUDY OF HEXAHALOOSMATES AND HEXACHLORORHENATE
Authors: Westland A. D. , Bhiwandker N. C.
Published: May 2006

The anomalously small magnetic moments of osmium(IV) and rhenium(IV) in their hexahalo complexes are investigated by measurement of the magnetic susceptibilities of the mixed crystal systems, K2OsCl6/K2PtCl6, K2OsBr6/K2PtBr6, and K2ReCl6/K2PtCl6. It is shown that only at high dilution is the magnetic behavior of the systems that which is expected from theory; therefore, extensive superexchange through the overlap of d-orbitals on the central atom and orbitals on the ligands takes place in the pure substances and in the concentrated systems. Determination of the spin–orbit coupling constant for OsCl62− provides a value in agreement with estimates based on spectra.
IMIDAZOLE SULPHONAMIDES AND RELATED COMPOUNDS
Authors: Fisher M. H. , Nicholson W. H. , Stuart R. S.
Published: May 2006

The preparations of a number of imidazole sulphonamides and related compounds are described.
CATALYTIC ACTIVATION OF MOLECULAR HYDROGEN BY RUTHENIUM (III) CHLORIDE COMPLEXES
Authors: Harrod J. F. , Ciccone Stefania , Halpern J.
Published: May 2006

Ruthenium(III) chloride, in aqueous HCl solution, was found to activate H2 homogeneously and to catalyze the reduction by H2 of Ru(IV)and Fe(III). The kinetics of these reactions were examined and, in each case, the rate law was found to be −d[H2]/dt = k1[H2][RuIII] where k1 = 4.0 × 1014 exp [−23,800/RT] M−1 sec−1. The mechanisms of these reactions are discussed and compared to those of other homogeneously catalyzed reactions of hydrogen. A special feature of the present system is the resistance of the catalytic species itself (i.e. RuIII) to reduction by H2.
A CHEMILUMINESCENT REACTION
Authors: Holden H. W. , Kutschke K. O.
Published: May 2006

not available
THE SYNTHESIS OF 17α-FLUOROPROGESTERONE
Authors: Deghenghi R. , Gaudry R.
Published: May 2006

not available
SOME REMARKS ON AGGREGATION OF POLYTHENE IN SOLUTION
Authors: Schreiber H. P.
Published: May 2006

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THE KINETICS OF REACTION OF 2,2-DIPHENYL-1-PICRYLHYDRAZYL WITH PHENOLS
Authors: Hogg J. S. , Lohmann D. H. , Russell K. E.
Published: May 2006

The kinetics of reaction between 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a wide variety of phenols have been studied. The rate of disappearance of DPPH is of first order with respect to both the DPPH and the reacting phenol. The rates of reaction can be roughly correlated with the Hammett σ value of the phenol substituent in the range −0.4 < σ < 0.2, a ρ value of −6 being obtained. t-Butyl groups in both ortho positions of the phenol give rise to steric hindrance, the reduction in rate being largely due to a reduction in the A factor. Hydrogen abstraction from the less reactive phenols is strongly retarded by the product, 2,2-diphenyl-1-picrylhydrazine.The rate-determining step probably involves the abstraction of a hydrogen atom from the phenol by the DPPH to give diphenylpicrylhydrazine and a phenoxy radical. The retardation by diphenylpicrylhydrazine is readily explained if this primary step is reversible.
HELMINTHOSPORAL, THE TOXIN FROM HELMINTHOSPORIUM SATIVUM: I. ISOLATION AND CHARACTERIZATION
Authors: Mayo P. de , Spencer E. Y. , White Robert W.
Published: May 2006

The toxin produced by Helminthosporiumsativum P.K. and B•4 has been isolated in crystalline form. It has the formula C15H22O2 and has been shown to contain one saturated aldehyde function, one α,β-unsaturated aldehyde, and two carbocyclic rings.
THE CRYSTALLIZATION OF POLYAMINO POLYACETIC ACIDS IN AN ION EXCHANGE MEMBRANE CHAMBER
Authors: Kuntze R. A.
Published: May 2006

not available
SOME NEUTRAL AND ACIDIC EXTRACTIVES FROM CEANOTHUS AMERICANUS L.
Authors: Abramovitch R. A. , Tertzakian G.
Published: May 2006

not available
CORRELATIONS OF INFRARED GROUP FREQUENCIES AND BAND INTENSITIES IN ORGANIC MOLECULES WITH SUBSTITUENT CONSTANTS: A STATISTICAL EVALUATION
Authors: Rao C. N. R. , Venkataraghavan R.
Published: May 2006

A statistical evaluation of the empirical linear correlations of infrared group frequencies and band intensities in aliphatic and benzene derivatives with substituent constants has been carried out. The correlations of frequencies with substituent constants generally give low standard deviations and acceptable correlation coefficients, and may thus be employed for the estimation of substituent constants. The correlations of band intensities with substituent constants show an interesting trend of the sign and magnitude of the slopes (ρ values) with the electrical property of the bond or group involved in the vibration. The ρ value decreases with the increasing electron-withdrawing power of the group.
THE RADIOLYSIS OF CYCLOHEXANE: IV. BINARY MIXTURES IN THE VAPOR PHASE
Authors: Ramaradhya J. M. , Freeman G. R.
Published: May 2006

The variation of the hydrogen yield with the composition of binary gaseous mixtures containing cyclohexane and benzene, cyclohexene, or propylene is qualitatively similar to that in the liquid phase.The quantitative experimental data were tested against several possible reaction mechanisms and two mechanisms gave straight-line plots.One mechanism involved scavenging of hydrogen atoms. The values of the kinetic parameters derived from this mechanism might not be unreasonable in the mixtures of cyclohexane with cyclohexene or propylene. The values for benzene, however, seem less likely.The second mechanism involved the transfer of energy (excitation or ionization) from cyclohexane to the second substance. The values of the ratio of the rate constants, k7/k6, of the reactions[Formula: see text]is about 103 times greater in the gas than in the liquid phase. Consideration of possible detailed mechanisms of reactions [6] and [7] indicates that this difference is reasonable if C6H12** is a positive ion rather than an excited molecule.