bluuebunny/crossref_metadata_2025 huggingface dataset:
STEADY-STATE THEORY OF ADSORPTION PSEUDOCAPACITANCE IN ELECTROCHEMICAL RADICAL-ION REACTIONS
Authors: Conway B. E. , Gileadi E.
Published: May 2006

The theory of adsorption pseudocapacity behavior is developed for a sequence of electrochemical reactions involving an ion discharge step which produces an adsorbed radical, followed by an "ion–atom" recombination reaction with or without desorption of the product of this step. The adsorption pseudocapacity behavior is deduced analytically particularly for the steady-state case and distinguished from the results obtained for assumed quasi-equilibrium in the ion discharge step when the succeeding step is rate-controlling. The effect of variation of the relative values of the rate constants of the discharge and of succeeding steps is investigated. It is shown that the capacity-potential behavior is sensitively dependent on the ratio of these rate constants, particularly for the case of adsorption isotherms involving a large value for the "heterogeneity parameter", r, defining the variation of energy of adsorption of the intermediates with coverage. Under the latter conditions, limiting coverages of the electrode by the adsorbed species are reached with increasing potential, depending on the relative values of the rate constants and the value of r.
THE STRUCTURE AND STEREOCHEMISTRY OF ATISINE
Authors: Dvornik D. , Edwards O. E.
Published: May 2006

A stereospecific hydration of the exocyclic methylene group of a derivative of the alkaloid atisine has been observed. The product was used to degrade the alkaloid to a tetracyclic phenol. This enabled rigorous proof of the structure and relative and absolute stereochemistry of atisine and related alkaloids. A detailed explanation of the abnormal basic strength and the isomerization of atisine is given. Long-range influence of polar groups on the basic strength of derivatives of the alkaloid is reported.
COMPOUNDS OF THE TYPE M5X2: DETERMINATION OF THE SPACE GROUP OF PENTA NICKEL DIARSENIDE (Ni6As2) USING VAPOR-GROWN SINGLE CRYSTALS
Authors: Saini G. S. , Calvert L. D. , Taylor J. B.
Published: May 2006

Single crystals of Ni5As2 have been grown by vapor transport reactions involving the use of either bromine or iodine. Crystals and whiskers have also been grown in the absence of halogen. In neither case did the maximum dimensions of the crystals exceed 0.5 mm.Ni5As2 is hexagonal with space group P6322: a = 6.81, c = 12.48 Å.
THE STRUCTURES OF TWO NEW ALKALOIDS: CHASMACONITINE AND CHASMANTHININE
Authors: Achmatowicz Jr O. , Marion Léo
Published: May 2006

A re-examination of the root of Aconitumchasmanthum Stapf has shown that it contains several alkaloids. Of these, besides indaconitine, the presence of which had been reported long ago, four new alkaloids have been isolated: base A (C26H43O6N), base B (C25H41O6N), chasmaconitine (C34H47O9N), and chasmanthinine (C36H49O9N). Chasmaconitine gives rise to bikhaconine on hydrolysis, and has been shown by conversion to delphinine to be N-ethyl-N-desmethyl-delphinine. Chasmanthinine is also hydrolyzable to bikhaconine. Whereas in chasmaconitine bikhaconine is esterified with acetic and benzoic acid, in chasmanthinine it is esterified with acetic and trans-cinnamic acid. The complete structures and absolute configurations of both bases are derived.
THE SYNTHESIS OF GLUCOAPPARIN
Authors: Benn M. H.
Published: May 2006

not available
N-SULPHONYLIMINO ESTERS
Authors: Love Bernard , Kormendy Minerva F.
Published: May 2006

not available
SYNTHESIS OF BISNAPHTHOXAZOLES
Authors: Rai Charanjit , Braunwarth John B.
Published: May 2006

not available
RELATION ENTRE LA DISSYMETRIE DES RAIES DE RESONANCE MAGNETIQUE NUCLEAIRE ET CERTAINS PARAMETRES STRUCTURAUX
Authors: Tiggelen Pierre J. van
Published: May 2006

We give here an equation describing the dissymmetry of nuclear magnetic resonance lines by means of the dipolar influence of the paramagnetic centers. In simple cases this equation coupled with the value of the second moment, will give us two structural parameters from spectra taken on powder samples.
ÉTUDE INFRAROUGE DES ACIDES FLUO- ET CHLORO-SULFURIQUES
Authors: Savoie Rodrigue , Giguère Paul A.
Published: May 2006

not available
FLUORANTHENE STUDIES
Authors: Charlesworth E. H. , Blackburn B. J.
Published: May 2006

3-Acetamido- and 3-amino-nuoranthene are brominated in the 2-position. Two new fluoranthene compounds are reported: 2-bromo-3-acetamidofluoranthene and 2-bromofluoranthene. The theoretical implications of these results are discussed.
THE REACTION OF CYCLOPENTANE VAPOR WITH Hg 6(3P1) ATOMS AT ELEVATED TEMPERATURES: THE RECOMBINATION, DISPROPORTIONATION, AND DECOMPOSITION OF CYCLOPENTYL RADICALS
Authors: Gunning Harry E. , Stock Richard L.
Published: May 2006

The static reaction of Hg 6(3P1) atoms with cyclopentane vapor (c-C5H10) has been studied with temperatures from 26 to 376°, at constant c-C5H10 concentration and at low light intensities.From 26 to 250°, the only important products are hydrogen, cyclopentene, and bicyclopentyl. Above 250° new products appearing are ethylene, biallyl, and allyl cyclopentane, together with smaller yields of propylene, ethane, propane, and methane. To 250°, the reaction can be explained in terms of a 5-step paraffinic sequence, involving initial C—H scission to form H atoms and cyclopentyl (c-C5H9) radicals. The Arrhenius plot of a function equal to kdisp/kcomb for c-C5H9 radicals showed that Edisp−Ecomb = 0. Above 250° c-C5H9 radicals decompose into C2H4 and C3H5 radicals. The activation energy for this process was determined from a number of product functions to be 36.9 ± 1.2 kcal/mole. Evidence was also found for scission of c-C5H9 into cyclopentene and H atoms, above ca. 300°.A brief examination was also made of the thermal decomposition of c-C5H10 up to 457° in a quartz reaction vessel. The substrate is unstable above 350° forming ethylene, propylene, cyclopentene, cyclopentadiene, and hydrogen. The rate data can be satisfactorily explained by two intramolecular decompositions of the substrate into (a) ethylene and propylene and (b) cyclopentene and hydrogen with the cyclopentene further dehydrogenating to cyclopentadiene. From the data Ea = 49.6 ± 2.0 kcal/mole and Eb = 44.0 ± 2.0 kcal/mole.
THE SESQUITERPENE ALCOHOLS OF THE HEARTWOOD OF THUJA OCCIDENTALS L.
Authors: Rudloff E. von , Nair G. V.
Published: May 2006

γ-Eudesmol, a mixture of α- and β-eudesmol, and a new sesquiterpene diol, occidiol, were found to be minor components of the neutral extract of eastern white cedar heartwood. A tentative structure for occidiol is proposed. The biogenetic relationship between these compounds is discussed and a common precursor for the eudesmol and occidentalol series is suggested.
PORE STRUCTURES AND SURFACE AREAS OF HARDENED PORTLAND CEMENT PASTES BY NITROGEN ADSORPTION
Authors: Mikhail R. Sh. , Copeland L. E. , Brunauer Stephen
Published: May 2006

The investigations were performed on five hardened pastes of a type I (normal) portland cement, having initial weight ratios of water to cement of 0.35, 0.40, 0.50, 0.57, and 0.70, and hydrated for 12, 12, 12, [Formula: see text], and [Formula: see text] years, respectively. The percentage hydration ranged from 90 to 98%.Nitrogen adsorption and desorption isotherms were determined for all pastes at the boiling point of nitrogen, from low pressures to almost the saturation pressure. The BET surface areas were calculated, and the pore space accessible to nitrogen was obtained by a slight extrapolation of the isotherms. In addition, pore structure analysis was made for three of the five pastes by the method of Cranston and Inkley.The specific surface areas of the five pastes were also determined by water vapor adsorption, and the total porosity to water was measured. For every paste, the water areas and porosities were greater than the nitrogen areas and porosities.The main conclusions from the results were as follows.(1) There is a wide range of pore sizes in the pastes.(2) Nitrogen is excluded from a part of the pore system by two mechanisms; some of the pores are too narrow and others have too narrow entrances to admit nitrogen.(3) The hydraulic radius (the volume of the pore system divided by the surface area of the pore walls) for the system of small pores increases with increasing water to cement ratio.(4) The hydraulic radius of the system of large pores also increases with increasing water to cement ratio, but the increase is smaller than for the small pores.(5) The paste with water to cement ratio of 0.35 has enough pore space for complete hydration.Some practical implications of the above conclusions are discussed.
PHOSPHONITRILIC COMPOUNDS: PART I. THE MECHANISM OF PHOSPHONITRILIC CHLORIDE POLYMERIZATION CAPACITANCE, CONDUCTANCE, AND ELECTRON-SPIN RESONANCE STUDIES
Authors: Allcock H. R. , Best R. J.
Published: May 2006

Capacitance and conductance measurements were carried out with molten (NPCl2)3 and [NP(OC6H5)2]3 and dipole moments were determined in benzene solution. Attempts to detect free radicals in molten samples of the same compounds were unsuccessful. Evidence was obtained that homolytic or heterolytic phosphorus–nitrogen ring cleavage is not involved in the primary initiation process. The results favor, instead, a polymerization mechanism for (NPCl2)3 in which phosphorus–chlorine ionization is a preliminary step.
STEROIDS: V. THE SYNTHESIS OF 4,4-DIMETHYL-3α,5-CYCLOCHOLESTAN-6-ONE (XI)
Authors: Just George , Richardson Keith St. C.
Published: May 2006

The synthesis of the title compound is described.
PHOTOLYSIS OF POLYMETHACRYLIC ACID IN AQUEOUS SOLUTIONS
Authors: Chou C. H. , Jellinek H. H. G.
Published: May 2006

The photolysis of polymethacrylic acid was studied in aqueous solutions as a function of pH, polymer concentration, polymer chain length, and small additions of electrolytes in the absence of oxygen with light of wavelength 2537 Å. The random chain scission constants decrease with increasing pH values. Small variations in polymer chain length and concentration and electrolyte concentration have no effect on the photolysis. Changes in the ultraviolet spectra with irradiation time are more pronounced at low pH values than higher ones. It is shown that the decrease in susceptibility to photolysis with increasing degree of ionization of the acid is not proportional to the decrease or increase of the number of COOH or COO−groups respectively. It is rather due to the same causes—that is changes in ionic atmosphere— which make the polymer chains uncoil with increasing ionization.
HINDERED CONFORMATIONAL ISOMERIZATION OF 9,10-DIHYDRO-9,9-DIMETHYL-10-METHYLENEANTHRACENES
Authors: Curtin D. Y. , Carlson C. G. , McCarty C. G.
Published: May 2006

While the n.m.r. spectrum of 10,10-dimethyl-9-methylene-9,10-dihydroanthracene (I) shows the geminal methyl group absorption as a sharp singlet the spectrum of the dibromo derivative, 10,10-dimethyl-9-dibromomethylene-9,10-dihydroanthracene (II) shows the methyl absorptions as two sharp well-separated peaks at room temperature which coalesce at 91°. 10,10-Dimethyl-9-phenylbromomethylene-9,10-dihydroanthracene (III), and the methyl ester (V) of IV show a broad geminal methyl spectrum at room temperature which separates to a doublet at lower temperatures and sharpens to a singlet at higher temperatures. Rate constants for the first-order processes responsible for the change in spectrum of II, III, and V have been calculated at the coalescence temperatures to be 57 (364 °K), 35 (305 °K), and 61 (300 °K) sec−1, respectively. The ΔH≠'s were used to extrapolate the rates to 305° to give values of 1, 40, and 100 sec−1, respectively. The process being studied is inferred to be the equilibrium between two boat conformations of the center ring in the dihydroanthracene system, rapid interconversion leading to identical environments for the two methyl groups. A comparison with the geometrically similar o,o′-disubstituted biphenyl racemization gives support for this explanation. A number of compounds with a proton and one substituent on the methylene carbon atom of I (substituents: bromine, chlorine, phenyl, carboxy, carbomethoxy, phenylmercapto) and also 10,10-dimethyl-9-phenylcarbomethoxymethylene-9,10-dihydroanthracene (XII) showed a single methyl absorption at room temperature. The methyl spectrum of the mono bromo compound VI did not broaden at temperatures down to 246 °K.
A GENERAL SYNTHESIS OF NUCLEOSIDES-5′ TRIPHOSPHATES
Authors: Moffatt J. G.
Published: May 2006

The reaction between ribo- and deoxyribo-nucleoside-5′ phosphoromorpholidates and tributylammonium pyrophosphate in molecular sieve dried dimethyl sulphoxide has been found to give the nucleoside-5′ triphosphates in 81–84% yields. A convenient work-up of the triphosphates following ion exchange chromatography permits isolation of the triphosphates in overall yields of 73–80% as the pure sodium salts. A number of examples of the reaction are given.
SYNTHESIS OF 5-ACETAMIDO SUBSTITUTED BARBITURATES
Authors: Singh Pritam , Berlinguet Louis
Published: May 2006

A series of 22 5-acetamido and 5-amino barbituric acids as well as corresponding thiobarbiturates and N-methylated derivatives have been prepared for hypnotic activity evaluation. From comparative studies of their infrared spectra, various frequencies have been ascribed to the acetamido and amino groups at C-5 position. S-Alkylation resulted in the formation of unstable thioethers which hydrolyzed to give corresponding barbituric acids and mercaptans.
PREPARATION AND CHARACTERIZATION OF CRYSTALS OF MX- AND MX2-TYPE ARSENIDES OF NIOBIUM AND TANTALUM
Authors: Saini G. S. , Calvert L. D. , Taylor J. B.
Published: May 2006

Phase analytical work on the systems niobium–arsenic and tantalum–arsenic has established the existence of mono- and di-arsenides as the only phases on the arsenic-rich side of the composition 50 atomic % As. Single crystals of these phases were grown by halide vapor transport reactions. The monoarsenides are tetragonal and isostructural. The lattice parameters of NbAs are a = 3.453 ± 0.002 Å, c = 11.672 ± 0.005 Å and of TaAs, a = 3.436 ± 0.002 Å, c = 11.644 ± 0.005 Å. The diarsenides are isostructural and have a C-face centered mono- clinic cell with a = 9.354 ± 0.002 Å, b = 3.381 ± 0.002 Å, c = 7.799 ± 0.002 Å, β = 119°26′ ± 5′ for NbAs2 and a = 9.350 ± 0.002 Å, b = 3.388 ± 0.002 Å, c = 7.760 ± 0.002 Å, β = 119°45′ ± 5′ for TaAs2.
THE HEARTWOOD EXTRACTIVES OF PINUS RESINOSA AIT•
Authors: Sato A. , Rudloff E. Von
Published: May 2006

The acetone extract of red pine heartwood was found to contain mainly pinosylvin monomethyl ether, oleic, linoleic, dehydroabietic, and isopimaric acids, and triglycerides of unsaturated fatty acids. Smaller amounts of pinosylvin, β-sitosteryl esters, and benzoic acid were isolated. Palmitic, palmitoleic, stearic, linoleic, pimaric, sandaracopimaric, abietic, neoabietic, vanillic, and three unidentified acids, as well as pinocembrin, vanillin, and eleven trace components were recorded by gas–liquid chromatography. A small amount of steam volatile oil, which may have taxonomic significance, was isolated. α-Pinene, β-pinene, myrcene, limonene, γ-terpinene, terpinolene, camphor, cis-p-menthan-8-ol, terpinen-4-ol, and α-terpineol were tentatively identified.Besides glucose and xylose, the methanol extract contained polylignan fractions similar to those which had been isolated previously from jack pine.
THE THERMAL REVERSIBILITY OF THE MICHAEL REACTION: I. NITRILES
Authors: Allen C. F. H. , Happ G. P.
Published: May 2006

Michael adducts of nitriles and α,β-unsaturated ketones have been found generally to undergo two or more kinds of thermal reversibility upon being heated to moderate temperatures. When the products are those from which the adduct was prepared, the dissociation is termed "normal," whereas the "abnormal" route gives an α,β-unsaturated nitrile and a methyl ketone. The scope and generality of the reversibility are described in three papers. The first deals with 31 ketonic nitriles, the second with nitroketones, and the last with diketones and acidic derivatives.Allowing the materials to decompose thermally in the heated inlet of a mass spectrometer permits a direct study of thermal reaction mixtures and it affords data the interpretation of which gives an indication of the products present, many of which may not have been previously expected. Identification of products is confirmed by comparison of the mass spectra with those of reference compounds. Under favorable conditions, such products can be isolated from independent decomposition reactions and their identities further confirmed by classical chemical methods. Both operations have been done often enough to show the general application of the mass spectrometer for this purpose. Thus laborious laboratory separations may be avoided. In two instances the four major products from both paths were isolated, identified, and quantitatively determined.
THE STABILITY OF THIOCOMPLEXES AND SOLUBILITY PRODUCTS OF METAL SULPHIDES: I. CADMIUM SULPHIDE
Authors: Ste-Marie J. , Torma A. E. , Gübeli A. O.
Published: May 2006

The nature and stability of cadmium sulphide complexes in aqueous solutions have been investigated. The total concentration of the metal in solution was determined at constant temperature and ionic strength, and at various pH values, by a radioactive tracer technique.
INFRARED AND RAMAN SPECTRA OF CYANURIC FLUORIDE
Authors: Griffiths James E. , Irish Donald E.
Published: May 2006

Infrared spectra (250–2000 cm−1) and Raman displacements (Δv = 100–1800 cm−1) with qualitative polarization measurements are reported for cyanuric fluoride. All of the active fundamentals are assigned on the basis of a planar D3h model: a1′ = 1496, 999, 642; e′ = 1617, 1424, 1087, 576, 378; a2″ = 817, 436; e″ = 743 and 226 cm−1.
THE REACTION OF N-BROMOSUCCINIMIDE WITH SOME ALKYL PYRIDINES
Authors: Kutney James P. , Cretney W. , Tabata T. , Frank M.
Published: May 2006

not available
CHLOROMETHYL ACETATE
Authors: Bavin P. M. G.
Published: May 2006

not available
REACTIONS OF (i) ALUMINUM TERTIARY BUTOXIDE WITH ACETYL CHLORIDE AND (ii) ALUMINUM CHLORIDE WITH TERTIARY BUTYL ACETATE
Authors: Mehrotra R. C. , Misra R. A.
Published: May 2006

The reactions between aluminum tertiary butoxide and acetyl chloride have been studied. The addition of 1 mole of acetyl chloride to aluminum tertiary butoxide forms monochloride ditertiary butoxide, which, with another mole of acetyl chloride, appears to give the dichloride monotertiary butoxide derivatives. Further, these products appear to react with tertiary butyl acetate formed in the reaction itself, giving acetate derivatives. The above is confirmed by a detailed study of the reactions between aluminum chloride and tertiary butyl acetate, which have been found to result in the acetate derivatives. A plausible mechanism has been suggested.
HIGH-FREQUENCY TITRATIONS: I. ARGENTIMETRIC DETERMINATION OF HALIDES AND THIOCYANATE IN METHANOL
Authors: Grey Peter , Cave G. C. B.
Published: May 2006

A new method is proposed for the determination of milligram amounts of each halide present in a mixture of alkali-metal halides. In some mixtures, thiocyanate also may be determined. A methanol solution of the sample is titrated in a closed-type cell, with a standard solution of silver nitrate in methanol. By using high-frequency titrimetry, and an appropriate concentration of the halide solution, sharp end points were obtained for each halide. Because of solid solutions, the accuracy of the determination of individual halides in mixtures depended on the mole ratios of the halides; the errors found in the titration of various binary, ternary, and quaternary mixtures are reported. For some binary mixtures, the total amount of halide titrated in 120 ml of methanol was varied from 0.5 to 500 micromoles. At the lower concentrations, addition of a small amount of sodium nitrate sharpened the end point. At all concentrations of halide, an excessive amount of indifferent electrolyte essentially eliminated the end points. The alkali-metal halides gave more satisfactory titration graphs than did some other metal halides. The effects of variation in temperature, and of solvent evaporation were noted.
ENERGY LEVELS OF TRIARYLMETHYL CARBONIUM IONS
Authors: Ng E. K. , Adam F. C.
Published: May 2006

The near ultraviolet and visible spectra of the various phenyl-, p-biphenyl methyl carbonium ions have been investigated and the polarization of the absorptions relative to the fluorescence band have been determined. An assignment of the transitions is made, using as a basis simple molecular orbital calculations and the expectations based on the structure representation. These are compared to the assignments made in earlier researches. The calculated intensities are found to agree favorably with the observed values.
PREPARATIONS OF DIALKYLAZOXYBENZENES AND THEIR DERIVATIVES
Authors: Newbold Brian T. , Tong Daniel
Published: May 2006

The three isomeric symmetrical dimethylazoxybenzenes have been prepared in very good yield by oxidation of the corresponding azobenzenes with peracetic acid. 2,2′- and 4,4′-Diethylazoxybenzenes have been synthesized by oxidation of the azobenzenes and reduction of the ethylnitrobenzenes. The diethylazoxybenzenes were also reduced to the corresponding azo-and hydrazo-benzene derivatives.
CATALYTIC HYDRODESULPHURIZATION OF THIOPHENE: V. THE HYDROTHIOPHENES. SELECTIVE POISONING AND ACIDITY OF THE CATALYST SURFACE
Authors: Desikan P. , Amberg C. H.
Published: May 2006

The hydrogenolysis of tetrahydrothiophene over sulphided cobalt molybdate – alumina was shown to proceed in two ways. The main reaction was hydrodecyclization to n-butanethiol and conversion of the latter to butenes and butane; the second and less prominent reaction involved dehydrogenation to thiophene, which was also desulphurized. The overall desulphurization activity decreased in the order n-butanethiol > tetrahydrothiophene > 2,3-dihydrothiophene > thiophene. A better understanding of the dual catalytic nature of the catalyst resulted from selective poisoning experiments with H2S, thiophene, methylthiophene, pyridine, and NH3. The sites responsible for olefin hydrogenation were shown to have strong affinity for thiophenes, H2S, and pyridine, as well as limited capacity to dehydrogenate thiolane and desulphurize thiophenes. Sites weakly electrophilic in character were also shown to be present on the catalyst surface. These could be poisoned only by ammonia or alkali and have been identified with the bulk of the desulphurization in the hydrogenolysis of thiophenes, hydrothiophenes, and thiol.
SECONDARY KINETIC ISOTOPE EFFECTS IN BIMOLECULAR NUCLEOPHILIC SUBSTITUTIONS: I. DEUTERIUM EFFECTS IN THE BUNTE SALT REACTION
Authors: Leffek K. T.
Published: May 2006

The secondary deuterium isotope effects have been measured for the reaction between sodium thiosulphate and α-deuterated methyl, ethyl, and n-propyl bromide, and also for β- and γ-deuterated n-propyl bromide, in aqueous ethanol solvent. The α-deuterium isotopic rate ratios (kH/kD) are all greater than unity. These unexpected results are discussed with respect to the suggested use of the α-deuterium isotope effect as a test of mechanism in nucleophilic substitutions.
STUDIES ON THE URANIUM EXTRACTION EQUILIBRIA, PHOTOLYTIC, AND HYDROLYTIC REACTIONS IN SYSTEMS CONTAINING TRI-n-BUTOXYETHYL PHOSPHATE
Authors: Halpern M. , Kim T. , Kertes A. S. , Li N. C.
Published: May 2006

The extraction equilibria in the system aqueous hydrochloric acid – uranyl chloride –undiluted tri-n-butoxyethyl phosphate, TBEP, were examined as a function of increasing uranyl concentration (0.44 to 4.41 M) in the initial aqueous solution, the acid content of the initial aqueous solution being kept constant at 6.76 M. The extraction behavior of TBEP is found to be different from that of tributyl phosphate. Evidence has been presented to show that the three ethereal oxygen atoms in the TBEP molecule are, under high organic phase loading conditions, available for participation in complexation. The hydrochloric acid promoted hydrolysis of TBEP and the instability toward light of the TBEP layer containing hydrochloric acid and uranium were also examined.
STATISTICAL PROBABILITIES OF SOME ARRANGEMENTS OF SOLUTE MOLECULES ON SUBSTITUTIONAL SITES IN CUBIC-CLOSE-PACKED CRYSTALS
Authors: Harvey K. B. , Shurvell H. F. , Henderson J. R.
Published: May 2006

Assuming a random distribution of solute molecules on substitutional sites of a cubic-close-packed solvent crystal, the probabilities have been calculated of finding single solute molecules and pairs of solute molecules in various degrees of isolation. The probabilities have been derived as a function of solute concentration and for distances corresponding to the separation of first, second, third, and fourth nearest neighbors.
N.M.R. STUDIES OF BRIDGED RING SYSTEMS: II. UNUSUAL MAGNETIC DESHIELDING EFFECT ON THE BRIDGE METHYLENES OF NORBORNADIENE AND BENZONORBORNADIENE
Authors: Tori K. , Hata Y. , Muneyuki R. , Takano Y. , Tsuji T. , Tanida H.
Published: May 2006

Proton magnetic resonance spectra of some norbornane derivatives having double bonds and (or) a benzene ring in the skeleton were studied. Differences in the chemical shifts between the bridge methylenes of norbornene and benzonorbornene and that of norbornane result from the diamagnetic anisotropy effect of a double bond or a benzene ring being in good agreement with the values calculated theoretically. However, in the norbornadiene derivatives which have two double bonds or one olefinic double bond with a benzene ring in a part of the skeleton, the signals of their bridge methylenes show extraordinarily larger downfield shifts by about 0.8 p.p.m. than those expected from the additive shielding due to each π-electron system. This anomaly is not observed in bicyclo[2.2.2]octane ring series. A large transannular interaction between two π-electron systems in that system would be a major contribution to the above anomaly.
THE KINETICS OF THE CHELATION OF NICKEL (II) AND 1,10-PHENANTHROLINE
Authors: Barrett P. F. , Smith W. MacF.
Published: May 2006

The kinetics of the formation of the bidentate monocomplex of 1,10-phenanthroline and nickel (II) have been examined spectrophotometrically at ionic strength 0.5 over the range of temperatures 8 to 37 °C and over the range of hydrogen ion concentrations 0.01 to 0.30 molar. The kinetic behavior over the range of conditions is consistent with that found at 25 °C by Margerum, Bystroff, and Banks. The limiting values for the second-order rate constant for the reaction at high acidities have been assessed and imply associated values of ΔH≠and ΔS≠ of 9.5 kcal mol−1 and −5.3 e.u. respectively.
THE GOVALENT CHARACTER OF ALKALI ALKOXIDES
Authors: Bains M. S.
Published: May 2006

not available
LYCOPODIUM ALKALOIDS. VI. THE NATURE OF ALKALOID L.9
Authors: Ayer W. A. , Hogg A. N. , Soper A. C.
Published: May 2006

not available
REARRANGEMENT STUDIES WITH 14C. XVIII. 2-PHENYL-2-14C-ETHYL CHLORIDE FROM GAMMA-IRRADIATION OF 2-PHENYL-1-14C-ETHYL CHLORIDE
Authors: Lee C. C. , Kroeger D. J.
Published: May 2006

not available
HIGH-FREQUENCY TITRATIONS. II. ARGENTIMETRIC DETERMINATION OF MICRO AMOUNTS OF HALIDES IN METHANOL
Authors: Grey Peter , Cave G. C. B.
Published: May 2006

not available
THE INFLUENCE OF SUBSTITUENTS ON THE EASE AND DIRECTION OF RING OPENING IN THE LiAlH4–AlCl3 REDUCTIVE CLEAVAGE OF SUBSTITUTED 1,3-DIOXOLANES
Authors: Leggetter B. E. , Brown R. K.
Published: May 2006

The room temperature hydrogenolysis by LiAlH4–AlCl3 of ether solutions of a number of 1,3-dioxolanes has been studied.Electron donor substituents on the C2 atom of the ring accelerate while electron acceptor substituents on C2 retard the reductive ring cleavage. The same effect but to a lesser extent is observed when these substituents are attached to the C4 or C5 atom of the ring.When electron donor substituents are attached to C4, ring cleavage occurs predominantly at the C2—O bond remote from the C4 position. On the other hand, electron-withdrawing groups attached to C4 give predominantly scission of the C2—O bond closer to the C4-substituted position. In contrast to this marked control over the direction of ring cleavage exhibited by substituents on C4, those on C2 generally have little or no effect on the direction of ring opening.A mechanistic interpretation of the results is presented.
ANOMALOUS RING CLEAVAGE DURING LITHIUM ALUMINUM HYDRIDE – ALUMINUM CHLORIDE REDUCTION OF 2,2,4,4-TETRAALKYLATED-1,3-DIOXOLANES
Authors: Leggetter B. E. , Brown R. K.
Published: May 2006

The anomalous reductive cleavage by LiAlH4–AlCl3 of 2,2,4,4-tetramethyl-1,3-dioxolane in ether solution has been examined. Evidence supports the view that this unexpected direction of ring cleavage is due to steric repression of the formation of the intermediate oxocarbonium leading to cleavage of the C2—O1 bond of the dioxolane ring.
THE METAL-CATALYZED AUTOXIDATION OF TETRALIN: III. CATALYSIS BY MANGANESE, COPPER, NICKEL, AND IRON
Authors: Kamiya Y. , Ingold K. U.
Published: May 2006

The catalysis of the autoxidation of tetralin by the decanoates of manganese, copper, nickel, and iron has been examined over a large concentration range at 50 °C. With all four metals the oxidation rate approaches a limit at high catalyst concentrations but in each case this limit is smaller than the theoretical maximum rate of oxidation of pure tetralin (Y. Kamiya etal. Can. J. Chem. 41, 2020 (1963)). However, upon dilution with an inert solvent, such as chlorobenzene, or with the metal acetates, acetic acid, the theoretical maximum rate is attained. The low limiting rates in pure tetralin are apparently due to the low solubilities of the catalysts and are not due to chain termination by the catalysts.
CO-ORDINATION COMPLEXES OF GROUP (IV) HALIDES: PREPARATION AND INFRARED SPECTRA OF THE CO-ORDINATION COMPOUNDS OF TITANIUM TETRACHLORIDE, TITANIUM TETRABROMIDE, ZIRCONIUM TETRACHLORIDE, TIN TETRACHLORIDE, AND BORON TRICHLORIDE WITH ETHYL CYANOACETATE AS LIGAND
Authors: Jain Sumer Chand , Rivest Roland
Published: May 2006

Co-ordination compounds between ethyl cyanoacetate and boron trichloride, titanium tetrabromide, and tetrachlorides of titanium, zirconium, and tin have been prepared. The analytical results indicate that under similar experimental conditions, 1:1 addition compounds are obtained in each case. On the basis of infrared spectra it has been postulated that the compounds obtained are six-membered ring chelates, satisfying the most common co-ordination number six for the elements of group IV.
PHOTOCONDUCTION AND SEMICONDUCTION IN MONOCRYSTALS OF THE CHARGE-TRANSFER COMPLEX, PERYLENE–FLUORANIL
Authors: KOKADO H. , Hasegawaj K. , Schneider W. G.
Published: May 2006

Single crystals of the perylene–fluoranil charge-transfer complex were found to be photoconductive throughout the near ultraviolet, visible, and near infrared spectral regions. The temperature dependence of the semiconduction and photoconduction are characterized by apparent activation energies of 0.73 ev and 0.12 ev, respectively. Conductivity parallel to the c-crystallographic axis (along which the complex units are stacked in columns) was found to be about threefold greater than that in the perpendicular direction. Attempts to measure carrier mobilities proved unsuccessful. The results suggest extrinsic carrier generation accompanied by pronounced carrier trapping processes.
THE THEORY OF ULTRASONIC ABSORPTION: RELAXATION OF TWO INTERACTING REACTIONS
Authors: Valleau J. P.
Published: May 2006

The purpose of this paper is to extend the theory of ultrasonic absorption in fluids to the case of the relaxations of two interacting reactions. The linear theory of the absorption and dispersion of sound waves is developed in terms of a frequency-dependent viscosity coefficient. This coefficient is then evaluated for the familiar case of a single relaxing reaction and for the more complex case of two reactions interacting in an arbitrary way. The absorption and dispersion of the sound waves are related to familiar physical chemical quantities by explicit formulae, and non-ideality has been taken account of by the use of activity coefficients. Some discussion of the results is presented. The intention of this development is to make possible the extraction of physical chemical data from ultrasonic investigations of systems involving interacting equilibria, and such an application has been made in an accompanying paper.
THE PYROLYSIS OF TRIMETHYLINDIUM
Authors: Jacko M. G. , Price S. J. W.
Published: May 2006

The pyrolysis of trimethylindium has been studied in a toluene carrier flow system from 550 °K to 781 °K using total pressures from 6.0 to 33.5 mm. The progress of the reaction was followed by measuring the amount of methane, ethane, ethylene, propane, and ethylbenzene formed and in a number of cases by direct indium analysis. The decomposition occurs in three steps: [Formula: see text]At all temperatures reaction [2] follows rapidly after reaction [1]. Reaction [3] occurs at a measurable rate only at temperatures sufficiently high that reactions [1] and [2] are completed in a very small fraction of the contact time. At lower temperatures the InCH3 produced deposits in the reaction zone as a white film of (InCH3)n.Both k1 and k3 decline rapidly if the toluene-to-alkyl ratio is decreased below 150. In an unseasoned vessel, the decomposition is markedly dependent on surface conditions. In the unpacked conditioned vessel the reaction is at least 89% homogeneous in the first bond region and 97% homogeneous in the third bond region. Both k1 and k3 depend on the total pressure in the system, the dependence of k1 being very slight. A least squares analysis of the experimental results gives: [Formula: see text]at 13.0 mm. E1 may be directly related to D[(CH3)2In—CH3]. A rough calculation based on unimolecular pressure effects indicates that D[In—CH3] is probably about 2 kcal/mole greater than E3.
Cl35 PURE QUADRUPOLE RESONANCE FREQUENCIES IN THE CYCLIC PHOSPHONITRILIC CHLORIDE POLYMERS
Authors: Whitehead M. A.
Published: May 2006

Pure nuclear quadrupole resonance frequencies of Cl35 in the cyclic phosphonitrilic chloride polymers, (PNCl2)n have been observed for n = 3, 4, 5, and 6. For both the tetramer and hexamer two different crystal structures were studied. The observed frequencies are discussed assuming that the phosphorus–nitrogen ring system possesses a polyallylic bond structure. Several substituted polymers were examined [Formula: see text] but only diphenyl-tetrachloro trimer, [Formula: see text] gave a frequency measurement. The ratio of the Cl35 quadrupole frequencies in two compounds is compared with the ratio of the effective orbital electronegativities of the phosphorus atom in the compounds.
ISOLATION OF 4,6-O-(1′-CARBOXYETHYLIDENE)-D-GALACTOSE FROM THE EXOCELLULAR POLYSACCHARIDE OF CORYNEBACTERIUM INSIDIOSUM
Authors: Gorin P. A. J. , Spencer F. J. T.
Published: May 2006

not available
THE INITIAL RATE OF DECOMPOSITION OF WATER VAPOR BY AN ELECTRICAL DISCHARGE
Authors: Barton S. S. , Jones R. A. , Thyne D. E.
Published: May 2006

not available
THE EFFECT OF STRUCTURE ON THE THERMAL STABILITY OF HYDROPEROXIDES. II
Authors: Hiatt R. , Visser Teunis
Published: May 2006

not available
ON THE DIFFERENTIATION OF endo- AND exo-NORBORNYL DERIVATIVES BY CHEMICAL SHIFTS IN N.M.R. SPECTROSCOPY
Authors: Wong Edward W. C. , Lee C. C.
Published: May 2006

not available
SOLVENT EFFECTS ON HYDROCARBON AUTOXIDATIONS
Authors: Howard J. A. , Ingold K. U.
Published: May 2006

not available
THE ELECTRONIC SPECTRA OF SOME ANIONIC POLYMERIZATION SYSTEMS
Authors: Bywater S. , Johnson A. F. , Worsfold D. J.
Published: May 2006

The ultraviolet absorption spectra of living anionic polymerizing systems have been measured with sytrene, butadiene, and isoprene as the monomers; with lithium, sodium, and potassium as the alkali metals; and with tetrahydrofuran, cyclohexane, and benzene as the solvents. For any monomer the similarity of the spectra obtained with the various metals and solvents leads to the conclusion that the alkali metal – carbon band has the same structure under the various conditions. From other evidence the bond is considered to be ionic in all cases. The diene monomer anions in tetrahydrofuran solution were found to undergo a series of isomerizations, some of them comparable in speed to the consumption of monomer.
TRANSFORMATIONS OF ICE VI AND ICE VII AT ATMOSPHERIC PRESSURE
Authors: Bertie J. E. , Calvert L. D. , Whalley E.
Published: May 2006

The irreversible transformations that occur when ices VI and VII are heated at atmospheric pressure from liquid-nitrogen temperature have been examined by simple thermal analysis and by X-ray diffraction. They transform first to cubic ice I (ice Ic) which subsequently transforms to hexagonal ice I (ice Ih). The rates of transformation depend on the temperature. The heat evolved is 16 ± ~2 cal/g for ice VI and 31 ± ~4 cal/g for ice VII.
THE ACID HYDROLYSIS OF GLYCOSIDES: I. GENERAL CONDITIONS AND THE EFFECT OF THE NATURE OF THE AGLYCONE
Authors: Timell T. E.
Published: May 2006

First-order rate coefficients and energies and entropies of activation have been determined for the acid-catalyzed hydrolysis of a number of methyl D-glycopyranosides and disaccharides. The relation between the logarithm of the rate coefficients and values for Hammett's acidity function was linear, although different for different acids. All compounds had entropies of activation indicating a unimolecular reaction mechanism. Glucosides of tertiary alcohols were hydrolyzed very rapidly, triethylmethyl β-D-glucopyranoside, for example, 30,000 times taster than the corresponding methyl compound.Increase in size of the aglycone caused a slight increase in the rate of hydrolysis of β-D-glucopyranosides, steric hindrance thus being of no significance. Electron-attracting substituents in the aglycone had little or no influence on the rate of hydrolysis, obviously because they would tend to lower the equilibrium concentration of the conjugate acid, while facilitating the subsequent heterolysis, the two opposing effects more or less cancelling out. These results were discussed in connection with recent studies on the acid hydrolysis of various phenyl glycopyranosides and with reference to the postulated occurrence of an activating inductive effect in oligo- and poly-saccharides containing carboxyl or other electronegative groups at C-5. It was concluded that there is little evidence for the existence of any such effect and that, for example, pseudoaldobiouronic acids should be hydrolyzed at the same rate as corresponding neutral disaccharides.
SYNTHESIS OF ALKYL 2-DEOXY-α-D-GLYCOPYRANOSIDES AND THEIR 2-DEUTERIO DERIVATIVES
Authors: Lemieux R. U. , Levine S.
Published: May 2006

The methyl, cyclohexyl, and t-butyl 2-deoxy-2-iodo-α-D-manno-and β-D-glucopyranoside triacetates were formed in near quantitative yield on reaction of equimolar amounts of the corresponding alcohol, iodine, D-glucal triacetate, silver perchlorate, and 2,4,6-trimethylpyridine (collidine) in dry benzene. The proportion of the α-D-manno isomer in the product increased in the order, t-butyl > cyclohexyl > methyl. Deuterolysis of the iodide in the presence of palladium proceeded with retention of configuration when the iodine was in equatorial orientation (β-D-gluco-configuration) but with near complete lack of stereospecificity when axially oriented (α-D-manmo-configuration).
THE SYNTHESIS OF ANHYDROUS ZIRCONIUM TRICHLORIDE
Authors: , B. , Flengas S. N.
Published: May 2006

not available
C13 CHEMICAL SHIFTS IN ORGANIC CARBONYL GROUPS
Authors: Stothers J. B. , Lauterbur P. C.
Published: May 2006

The results of a study of the resonance position of the carbonyl carbon nucleus in an extensive series of carbonyl derivatives are reported. A discussion of the major factors affecting the position of these carbon resonances is presented and some of the potential applications of these data to chemical problems are indicated.
AROMATIC SUBSTITUTION: PART VII. COMPETITIVE REACTIONS OF PYRIDINE, 3-PICOLINE, AND 3-ETHYLPYRIDINE WITH PHENYLLITHIUM. ACTIVATION OF A NUCLEOPHILIC AROMATIC SUBSTITUTION BY ALKYL GROUPS
Authors: Abramovitch R. A. , Giam Choo-Seng
Published: May 2006

The relative reactivities of pyridine, 3-picoline, and 3-ethylpyridine towards phenyllithium have been measured under various conditions by a competitive technique and have been found to be in the order: 3-picoline > pyridine > 3-ethylpyridine. A 3-methyl or ethyl substituent activates the 2-position relative to that in pyridine itself, while C6 is deactivated as expected. A possible explanation is put forward for these observations and for the somewhat low yields that are obtained in such reactions. A method is described whereby arylation of pyridines with aryllithium compounds may be effected in high yields.
THE KINETICS OF THE REACTION OF ATOMIC HYDROGEN WITH METHANE
Authors: Jamieson J. W. S. , Brown G. R.
Published: May 2006

Reinvestigation of the reaction of hydrogen atoms, produced by electric discharge, with methane in a fast flow system has given an activation energy of 7.4 ± 1.1 kcal/mole and a steric factor of about 10−3 for the primary reaction, H + CH4 → H2 + CH3.
A GROUP ORBITAL STUDY OF LITHIUM HYDRIDE
Authors: Csizmadia I. G. , Sutcliffe B. T. , Barnett M. P.
Published: May 2006

A quantum mechanical treatment of lithium hydride in the group orbital approximation is presented. Some excited states and an improved ground state are obtained by means of configuration interaction within a single group.The total energy obtained for the ground state at several interatomic distances (R = 2.0–8.0 a.u.) omitting and including configuration interaction and for the first excited singlet state compare very well with the values reported by Karo in a comparable simple molecular orbital calculation.The chemical significance of the group orbital method is discussed. The results of the present calculations are related to some chemical reaction mechanisms and to some spectroscopic phenomena.
ANTINEOPLASTIC AGENTS: XI. N-BIS(2-BROMOETHYL)AMINES
Authors: Pettit George R. , Chamberland Maurice R. , Blonda David S. , Vickers Martyn A.
Published: May 2006

A novel halogen exchange reaction was found to accompany condensation of an acyl chloride with N-bis(2-bromoethyl)amine. Reaction between an acyl bromide and N-bis(2-bromoethyl)amine, however, gave the expected N-bis(2-bromoethyl)amide. A number of N-alkyl-N-bis(2-bromoethyl)amines were prepared by lithium aluminum hydride reduction of the corresponding N-bis(2-bromoethyl)amides. The overall transformation from N-bis(2-bromoethyl)amine presents a convenient route to certain bromo nitrogen mustards. An efficient synthesis of N-bis(2-iodoethyl)amine hydroiodide is also described.
REACTION OF 2-METHYL-2-NITRO-1,3-PROPANEDIOL WITH ALKALI
Authors: Unrau A. M.
Published: May 2006

Hydrolysis of 2-methyl-2-nitro-1,3-propanediol with strong alkali (20% NaOH) resulted primarily, as expected, in a reverse aldol decomposition, although a small but significant quantity of free nitrite ion was detected. Hydrolysis with alkaline borate (pH 10) gave high yields of nitrite ion. Possible mechanisms to explain these results are presented. The major product formed in the borate hydrolysis was identified as 2-C-methyl glycerol (2-methyl-1,2,3-propanetriol). A number of minor products were also detected by vapor-phase chromatography.
THE STRUCTURE OF FERROCENYL RUTHENOCENYL KETONE
Authors: Small G. J. , Trotter J.
Published: May 2006

not available
ALUMINUM HYDRIDE DERIVATIVES FROM THE REACTIONS OF LITHIUM ALUMINUM HYDRIDE WITH TRIMETHYLAMINE AND DIMETHYLAMINE
Authors: Peters Frances M.
Published: May 2006

not available
METHOXYCARBOSTYRILS
Authors: Pettit George R. , Neill Alexander B.
Published: May 2006

not available
EFFECT OF PRESSURE ON THE ACID-CATALYZED ENOLIZATION OF ACETONE AND ACETOPHENONE IN VARIOUS ETHANOL–WATER SOLVENTS. ORIGIN OF THE ENTHALPY–ENTROPY COMPENSATION EFFECT
Authors: Baliga B. T. , Whalley E.
Published: May 2006

The effect of pressure, temperature, and solvent composition on the rate of the acid-catalyzed enolization of acetone and acetophenone, and the solvent deuterium isotope effect for the enolization of acetophenone, have been measured by following the iodination. The solvent deuterium isotope effect [Formula: see text] for the enolization of acetophenone in 16.2% w/w ethanol–water is 2.50 ± ~0.05, which undoubtedly proves that there is a pre-equilibrium proton transfer. The effect of solvent in the range water to 33.4% w/w ethanol in water on the rate of enolization of both acetone and acetophenone is small at atmospheric pressure, but is about four times larger at 3 kbar. This cannot be explained on simple electrostatic grounds, and indicates that any simple electrostatic explanation of the solvent effect at atmospheric pressure is invalid. The volumes of activation for the enolizations are strongly dependent on the solvent, that for acetone varying from −2.l ± ~0.5 to −6.9 ± ~ 0.7 cm3 mole−1 between solvents water and 33.4% w/w ethanol in water.An examination has been made of the enthalpyentropy compensation effect. It is shown that in general if the rate or equilibrium constant of a reaction does not change with changing conditions (such as solvent, substituents, etc.) then either the quantities of activation at constant pressure, ΔHp≠ and ΔSp≠, or the corresponding quantities at constant volume, ΔUv≠ and ΔSv≠, must vary in a compensating manner, and the existence of an energy–entropy compensation effect is inevitable. For the enolization of acetone and acetophenone in ethanol–water mixtures, ΔUv≠ and ΔSv≠ vary only slightly with solvent, whereas ΔHp≠ and ΔSp≠ vary in a compensating manner. The main causes of the compensation effect in the constant-pressure parameters are, in a sense, the change with changing solvent of the thermal expansion of the solvent and of the volume of activation of the reaction. On the other hand, both the constant-pressure and the constant-volume parameters vary with substituent from acetone to acetophenone, and the constant-volume parameters vary the more.
RADIOLYSIS OF CYCLOHEXANONE: II. EFFECT OF SOLUTES ON PRODUCTS INVOLVING C—H BOND RUPTURE
Authors: Singh Ajit , Freeman Gordon R.
Published: May 2006

Some of the products whose formation, during the radiolysis of cyclohexanone, involves the rupture of C—H bonds are hydrogen, cyclohexanol, 2,2′-diketodicyclohexyl, and probably other "dimers" of cyclohexanone.Benzene appears to inhibit the formation of hydrogen mainly by an activation transfer process. The influence of 2,3-dimethyl-1,3-butadiene (DMB) on the hydrogen yield is more complex and probably involves more than one inhibition reaction.Less than one mole percent of DMB or of oxygen inhibits the formation of cyclohexanol and of dimers to below their limits of detection on the analytical system (G < 0.2). This is probably due to the scavenging of free radicals (G(scavengeable radicals) = 4). Benzene is much less efficient than DMB or oxygen in inhibiting the formation of cyclohexanol and of dimers of cyclohexanone.
EFFECTS OF CHLORINE AND BROMINE ON THE RADIOLYSIS OF GASEOUS HCl
Authors: Lee R. A. , Davidow R. S. , Armstrong D. A.
Published: May 2006

Using an ionization chamber method, it has been shown that the energy required to create an ion pair in gaseous HCl, WHCl is 24.4 ± 0.6 eV. The hydrogen yield, G(H2)HCl gas at 23 °C = 8.0 ± 0.3, was independent of HCl pressure in the range 19 to 119 cm of Hg. The effects of added bromine demonstrate that at least two species are involved in hydrogen formation, and there are strong indications that one of these is an electron. A second species, designated as H11 and formed with a yield [Formula: see text], is not readily scavenged by bromine. The use of chlorine as a scavenger also provides evidence for the presence of more than one hydrogen-forming species. The data of an earlier study of the α-particle radiolysis have been corrected for back reactions of the chlorine which accumulated in the system. The corrected results are in reasonable agreement with those of this study.