bluuebunny/crossref_metadata_2025 huggingface dataset:
THIAZOLOISOQUINOLINES: II. THE SYNTHESIS OF THIAZOLO[5,4-c]ISOQUINOLINE
Authors: Hall Catherine E. , Taurins Alfred
Published: May 2006

Thiazolo[5,4-c]isoquinoline (I) has been synthesized by cyclization of 4-amino-3-thiocyano-isoquinoline (IX) to 2-aminothiazolo[5,4-c]isoquinoline (X), which was converted into I via the 2-chloro derivative XI. Some 2-substituted derivatives of I were obtained by displacement of the chlorine atom in XI. The attempted preparation of 3-chloro-4-nitroisoquinoline as an intermediate in the synthesis of I was unsuccessful. Nuclear magnetic resonance and ultraviolet spectra of I and its derivatives were investigated.
A COMMENT ON THE INADEQUACY OF THE CORRELATION BETWEEN PHYLLO-TYPE SPECTRUM AND meso-SUBSTITUTION IN THE PORPHYRIN SERIES
Authors: Bonnett R. , Gale I. A. D. , Stephenson G. F.
Published: May 2006

The empirical correlation between meso-substitution and the phyllo-type spectrum in the porphyrin series is shown to be much less general than had previously been supposed. The variation of the spectrum with the electronic nature of the substituent is discussed.
ORMOSIA ALKALOIDS: III. CHEMISTRY OF ORMOSANINE AND ORMOJANINE; DEHYDROGENATION TO 3,6,8-TRIALKYLATED QUINOLINES
Authors: Valenta Z. , Deslongchamps P. , Rashid M. H. , Wightman R. H. , Wilson J. S.
Published: May 2006

Degradations of ormosanine, C20H35N3, are described which are in agreement with structure II (8) for this alkaloid. Nuclear magnetic resonance study of N-acetyl and N-nitroso derivatives has been used to clarify the environment of the secondary nitrogen atoms. Chemical and spectroscopic evidence leads to the formulation XVb for the related alkaloid ormojanine, C20H31N3.Both alkaloids were found to give 3-n-pentyl-6,8-dipropylquinoline together with the corresponding 3-n-butyl derivative in a catalytic dehydrogenation. The possible mechanism of formation of these dehydrogenation products is discussed and their synthesis is described.
MOLECULAR REARRANGEMENT OF DIAZOTIZED o-AMINOPHENYLCARBINOLS
Authors: Sisti A. J. , Cohen R. L.
Published: May 2006

not available
ÉTUDE DES SPECTRES DE RÉSONANCE PARAMAGNÉTIQUE ÉLECTRONIQUE DE RADICAUX ALLYLIQUES POLYORIENTÉS
Authors: Chachaty Claude , Maruani Jean
Published: May 2006

The effect of the hyperfine coupling anisotropy on the shape of the electron spin resonance spectra of randomly oriented allyl radicals has been studied by means of electronic computer calculation. The line shape has been shown to be strongly dependent on the relative orientation of the tensor axes, and it can be used, therefore, to characterize the structural isomerism of the radical. The comparison of the computed spectra, taking account of the ġ tensor anisotropy, with the spectra recorded after γ irradiation of several monoethylenic compounds, allowed the identification of the produced allyl radicals and showed that, in most cases, these radicals keep the geometrical configuration of the corresponding undamaged molecules.
PLATINUM(II) COMPLEXES CONTAINING α-HYDROXYACETYLENES
Authors: Allen A. D. , Theophanides T.
Published: May 2006

The structures of complexes of the types M[PtCl3ac] and trans-[PtCl2ac(amine)], where ac = a tertiary α-hydroxyalkyl- or α-methoxyalkyl-acetylene, are described. The coordination of the ligands to the metal is through both the triple bond and the hydroxyl groups. The infrared spectra of the complexes in the O—H stretching region (3 000 – 3 800 cm−1) and the effect on the spectra of the addition of bases to solutions of the free ligand and complexes strongly indicate that the hydroxyl groups are coordinated through the oxygen atom to the metal.
DEPENDENCE OF BOND ANGLES ON OVERLAP INTEGRALS FOR SOME COVALENT HYDRIDES
Authors: Hutchinson D. A.
Published: May 2006

An explicit relationship, between bond angles and overlap integrals, is developed for covalent hydrides of C3v and C2v symmetries. From this relationship it is argued that the bond angle depends on the overlap integrals of s and p functions with hydrogen 1s functions. The results of calculations of these overlap integrals are given; the calculations were first performed with Slater functions and repeated with approximate self-consistent-field functions. Arguments, based on the results of these calculations, are advanced as an additional explanation of why ammonia and water have larger bond angles than phosphine and hydrogen sulfide.
REACTIONS OF OZONIDES: IV. OZONIZATION OF ALKYLCYCLOALKENES
Authors: Diaper D. G. M.
Published: May 2006

Oxidative ozonolysis of some 1-alkylcyclopentenes, 1-alkylcyclohexenes, and 1-methylcycloheptene gives keto acids (RCO(CH2)nCOOH) and by-product derived esters now identified as RCO(CH2)nCOO(CH2)nCOR. The mechanisms of formation of esters from zwitterion and carbonyl intermediates are discussed in terms of dimeric zwitterions. Cycloalkanones also present in the neutral by-product are attributed to alkylidenecycloalkanes.
PHOTOCHEMICAL TRANSFORMATIONS OF DIENES: VII. STEREOCHEMISTRY OF ADDITION OF ALCOHOL, AND EFFECT OF SUBSTITUENTS AND ACIDS ON THE PHOTOCHEMISTRY OF CHOLESTA-3,5-DIENES
Authors: Bauslaugh G. , Just G. , Lee-Ruff E.
Published: May 2006

Results for the photolysis of 6-methylcholesta-3,5-diene are described. The photolysis of these and other dienes proceeds by a unimolecular process, giving bicyclobutanes, or a bimolecular process, giving carbonium ions. Reaction of the bicyclobutane with a protic solvent results in stereospecific incorporation of a proton (4β), whereas direct abstraction of a proton by a photo-excited species results in non-stereospecific abstraction. In the presence of small amounts of acid, more or in part new products, derived from the bimolecular pathway, are obtained.It was noted that the normal chromatographic elution sequence (alumina) of epimeric alcohols was reversed when thin-layer chromatography (silica gel) was used.
SUR LES PRÉSUMÉS cis-DIHALOGÉNURES DE QUINONES
Authors: Savoie J. Y. , Brassard P.
Published: May 2006

It has been proposed, mainly on the basis of spectral evidence, that the addition of chlorine to p-benzoquinone gives the cis-dichloride, and that in an alcoholic solution this substance isomerizes to the trans-dichloride, which then enolizes to the corresponding hydroquinone. Upon reexamination of the evidence and isolation of the intermediates and end products of the reaction in an alcoholic solution, it can now be reasserted that the trans-dichloride is the only detectable isomer resulting from chlorination under various conditions. The observed changes in an alcoholic solution have been proven to be the result of elimination followed by photochemical reduction. Similar conclusions have been reached in the case of quinone dibromides.
THE STRUCTURE OF SUCCINYL DIGHLORIDE
Authors: Schmid George H.
Published: May 2006

not available
AROMATIC SUBSTITUTION: XIV. THE HOMOLYTIC PHENYLATION OF 3- AND 4-PICOLINE. A QUANTITATIVE STUDY OF ISOMER AND TOTAL RATE RATIOS
Authors: Abramovitch R. A. , Saha Maitreyi
Published: May 2006

not available
SOME ADSORPTION PHENOMENA OF NITROANILINES ON ALKALINE EARTH COMPOUNDS
Authors: Frei R. W. , Zeitlin H. , Fujie G.
Published: May 2006

The spectral behavior of o- and p-nitroanaline adsorbed on various alkaline earth compounds has been studied by reflectance spectroscopy. Regular bathochromic shifts in the diffuse reflectance spectra have been observed for the absorption maxima in the visible region in order of increasing size of the adsorbent cation. Progressive removal of coadsorbed moisture which competes for active adsorbent sites resulted in an enhancement of the bathochromic shifts. The intensity of the absorption maxima as measured by peak heights was found to be dependent upon the size of both cations and anions of the adsorbents. Interpretation of observed phenomena was advanced in terms of electronic polarization theory and varying surface area of the adsorbents.
The nuclear magnetic resonance spectra of some related alkylene-substituted diethylamines
Authors: Freifelder Morris , Mattoon Richard W. , Kriese Russell
Published: May 2006

The nuclear magnetic resonance spectra of N1, N1-diethyl-2,2-dimethylpropane-1,3-diamine (I), bis-(3-diethylamino-2,2-dimethylpropyl) amine (II) and N1-(3-diethylamino-2,2-dimethyl) propylidene-N3, N3-diethyl-2,2-dimethyl-1,3-propanediamine (III) are examined. In the spectrum of I, separate single peaks are observed for the methylene groups adjacent to the primary and tertiary nitrogen atoms. In the spectrum of II, the symmetrical secondary amine, the pair of methylene groups adjacent to the secondary nitrogen atom appears as a singlet separate from the methylene protons between the tertiary carbon and nitrogen atoms. Acetylation of I and II makes it possible to identify the methylene signals of each compound. In the spectrum of III, dissymmetry because of unsaturation [Formula: see text] is responsible for the differences in the peak positions of the signals of seemingly similar groups. This difference extends to the signals for the terminal methyl protons, which are six and seven bonds from the double bond.
The infrared spectrum of s-trinitrobenzene and s-trinitrobenzene-d3
Authors: Shurvell H. F. , Faniran J. A. , Symons E. A. , Buncel E.
Published: May 2006

Infrared spectra in the region 350 to 3 200 cm−1 have been recorded for s-trinitrobenzene and s-trinitrobenzene-d3. An assignment of 13 of the 15 infrared active vibrations of both molecules has been made. The assumption that s-trinitrobenzene is planar with D3h symmetry is supported by the analysis of the infrared spectrum. Vibrations involving the nitro groups are virtually unchanged upon deuteration of s-trinitrobenzene.
Effects of pressure and temperature on the structure of liquid acetone
Authors: Adams W. A. , Laidler K. J.
Published: May 2006

The compressibility of acetone has been redetermined at temperatures of 25 to 55 °C, and at pressures from atmospheric to 1 kbar. The results have been fitted to the Tait equation, and values of (∂P/∂T)V and of the internal pressure have been calculated. The heat capacity at constant volume has also been deduced as a function of pressure and temperature. The variations in these and other derived quantities have been shown to lead to conclusions about structural changes in the liquid.
Attack of related free radicals on methane. Arrhenius parameters and thermochemistry
Authors: Gray P. , Jones A.
Published: May 2006

The Arrhenius parameters of some 20 reactions, in which different atoms and radicals attack methane, have been compared in the light of the thermochemistry of the reactions. Attention has been focussed on family relationships amongst the attacking species.Where direct kinetic data are lacking, Arrhenius parameters have been calculated from data available for the reverse reactions.
Photochemical studies of α,β-unsaturated ketones in carbon tetrachloride solution
Authors: Mettee H. D.
Published: May 2006

Phosgene has been identified by infrared spectroscopy as one of the major products of both continuous and flash photolyses of dilute, oxygenated CCl4 solutions of six α,β-unsaturated ketones at wavelengths longer than 3 000 Å. This product is absent from degassed solutions photolyzed similarly. Acetone, benzophenone, naphthalene, and anthracene show parallel behaviour. s-trans ketones appear to be more effective in causing the CCl4 decomposition than the s-cis species. The photosensitized decomposition of CCl4 is a possible mechanism for this common behavior.
Apparent molal volumes of n-alkylamine hydrobromides in water at 25°C: hydrophobic hydration and volume changes
Authors: Desnoyers J. E. , Arel Marcel
Published: May 2006

The densities of aqueous solutions of the homologous salts RNH3Br, where R varies from H to n-octyl, have been measured at 25 °C to the sixth decimal place by a float method. From this series, it is possible to study the transition in behavior of typical simple salts to long-chain micellar salts. The apparent molal volumes extrapolated to infinite dilution can be used to evaluate the additivity of the volume of the methylene groups. The concentration dependence of the apparent molal volumes and the change in volume during micelle formation can be interpreted in terms of a competition between the increase in ice-likeness of water and loss of free space near the solute during hydrophobic hydration. The present results show no indications of dimerization of the cations below the critical micelle concentration.
Approximate method for calculating the third virial coefficient of a gaseous mixture
Authors: Orentlicher M. , Prausnitz J. M.
Published: May 2006

An approximation is suggested for calculating the third virial cross-coefficient Cijk from available generalized tables for pure-component third virial coefficients Ciii which are based on any one of several, spherically symmetric potential functions. A comparison of calculated results with the very limited experimental data now available indicates that the suggested approximation can reproduce the experimental results essentially within the probable (large) experimental uncertainty.
The reactions of the trifluoromethyl disulfide group, CF3SS—, with ammonia and amines. A new preparation of sulfenamides
Authors: Peach M. E.
Published: May 2006

Bistrifluoromethyl disulfide reacts with ammonia and primary and secondary amines, forming the compounds CF3SNH2, RNHSCF3, and R2NSCF3, respectively; also produced are ammonium fluoride and thiocyanate, or a substituted thiourea and hydrogen fluoride, which forms a salt with the amine or thiourea.Simple sulfenamides, RSNH2, can be prepared from ammonia and a trifluoromethyl disulfide, RSSCF3; ammonium fluoride and thiocyanate are also produced. Since the trifluoromethyl disulfides are formed from thiols and trifluoromethanesulfenyl chloride, the reaction offers a simple method for the conversion of thiols into sulfenamides.The new compounds N-propyltrifluoromethanesulfenamide, N,N-diethyltrifluoromethanesulfenamide, bispentafluorobenzenesulfenimide, pentafluorophenyltrifluoromethyl disulfide, and n-propyltrifluoromethyl disulfide have been prepared and characterized.
The alkaloids of Lycopodium cernuum L. III. The synthesis of dihydrodeoxyepiallocernuine
Authors: Ayer W. A. , Piers K.
Published: May 2006

The synthesis of dihydrodeoxyepiallocernuine (IV) is described, as is the synthesis of the tricyclic compound XVI, a degradation product of lycocernuine. These syntheses provide a rigorous proof of the constitution of cernuine and lycocernuine, and also provide strong support for the stereochemistry assigned to these alkaloids.
The C=S stretching vibration in the infrared spectra of some thiosemicarbazones
Authors: Wiles D. M. , Gingras B. A. , Suprunchuk T.
Published: May 2006

The infrared spectra of some aldehyde and ketone thiosemicarbazones have been compared over the region 1 200 to 700 cm−1with the spectra of the corresponding selenosemicarbazones. A band in the former at 830 to 805 cm−1is replaced by a band in the latter at 800 to 775 cm−1, attributed to v(C==Se). No other systematic differences are observed in this spectral region. The formation of 1:1 Cu(I) complexes of the thiosemicarbazones results in the removal of bands in two regions, 1 110 to 1 075 cm−1and 830 to 805 cm−1, from the spectra of the uncomplexed thiosemicarbazones. It is concluded that there is a contribution from v(C==S) in both regions, but that absorption in the lower region represents the more nearly pure C==S stretching vibration. Examination of the spectra of N–methyl substituted thiosemicarbazones indicates that, even in this 830 to 805 cm−1region, C==S stretching is coupled with other vibrations, perhaps N—C—N stretching.
Étude quantitative des réactions d'ozonolyse. V. Sur le clivage de l'ozonide primaire des styrènes substitués dans le noyau
Authors: Fliszâr S. , Renard J.
Published: May 2006

For the ozonization of ring-substituted styrènes, the proportions of the two ways of cleavage yielding (a)

[Formula: see text]and (b)

[Formula: see text]are related by the equation

[Formula: see text] to Hammett's σ and ρ constants (x = proportion of cleavage following route a; ▵▵Go≠ (0.22 kcal/mole at 25°C) = Gibbs activation energy difference between assumed transition states of the primary styrene ozonide). The interpretation in terms of transition states concludes that the zwitterion is preferentially formed at the carbon atom with the highest electron density.
The influence of pH and inhibitors on the kinetics of enzyme reactions involving two intermediates
Authors: Kaplan Harvey , Laidler Keith J.
Published: May 2006

General steady-state equations are worked out for enzyme reactions which occur according to the scheme

[Formula: see text]Equations showing the pH dependence of the kinetic parameters are developed in a form which distinguishes between essential and nonessential ionizing groups. The pK dependence of

[Formula: see text], the second-order constant extrapolated to zero substrate constant, gives pK values for groups which ionize on the free enzyme, but reveals such a pK only if the corresponding group is also involved in the breakdown of the Michaelis complex. General steady-state equations are also developed for the case in which an inhibitor can combine with the free enzyme, the enzyme–substrate complex, and also a second intermediate (e.g. an acyl enzyme). The equations are given in a form that is convenient for analyzing the experimental results, and a number of special cases are considered. It is shown how the type of inhibition depends not only on the nature of the inhibitor but also on that of the substrate, an important factor being the rate-determining step of the reaction. Examples of the various kinds of behavior are given.
Radiolysis in the adsorbed state. I. Cyclohexane adsorbed on silica gel
Authors: Sagert N. H. , Dyne P. J.
Published: May 2006

Isotopic labelling techniques have been used to study the Co-60 γ-radiolysis of cyclohexane adsorbed at low coverage on silica gel. It has been shown that some of the energy absorbed in the silica gel is able to cause decomposition of the hydrocarbon, but it has also been shown that the silica gel takes part in the system as a chemical reactant. The effect on the radiolysis of changing the chemical nature of the gel by varying the water content was studied and it is shown that the radiolysis is quite different over gels with low and high water content. These changes are ascribed to the replacement of silanol groups by siloxane groups, with the removal of chemisorbed water.The effect of the additives N2O and SF6 was studied in an attempt to determine how much of the reactivity was transferred from the solid by an ionic mechanism. It was concluded that over gels with a high water content more than one half of the reactivity was ionic in nature, whereas over gels with low water content much less was ionic.
A simple geminal approach to bonding. I. Helium–helium interaction
Authors: Peat F. David
Published: May 2006

The energy of a molecule may be expressed as the sum of two-electron energy levels; the weight factors involved in this sum may be determined in the zero-order approximation. This method is applied to the He–He interaction, the two-electron energy levels being calculated using a wave function containing a single-variation parameter. Reasonable agreement is obtained with experimental results.
Dimerization of conjugated cyclodienes
Authors: Suga Kyoichi , Watanabe Shoji , Kamma Keizo
Published: May 2006

Dimerization of conjugated cyclodienes in the presence of lithium–naphthalene gave new dimers. 1-(2′-Cycloocten-1′-yl)-2-cyclooctene was prepared from 1,3-cyclooctadiene, 1,4-dicyclohexyliden-n-butane from 1-vinyl-1-cyclohexene, and a terpene dimer from α-phellandrene.
Reactions of nitro sugars. V. Some reactions with methyl 3-deoxy-3-nitro-α-d-hexopyranosides
Authors: Baer Hans H. , Kienzle Frank
Published: May 2006

The acetylations and catalytic hydrogenations of derivatives of methyl 3-deoxy-3-nitro-α-d-hexopyranosides were compared with the analogous reactions previously performed in the β-anomeric series. The acetylation of methyl 4,6-O-benzylidene-3-deoxy-3-nitro-α-d-glucopyranoside (II) gave its 2-O-acetyl derivative III, which, upon base-catalyzed elimination of acetic acid, yielded the nitroolefin, methyl 4,6-O-benzylidene-2,3-dideoxy-3-nitro-α-d-erythro-hexopyranos-2-enide (IV), whereas acetylation of the corresponding α-d-talopyranoside XI proceeded with dehydration, giving directly the α-d-threo nitroolefin XIII. These courses of reaction had their counterparts in the β-series and are believed to depend on the configurations at C-4. On the other hand, palladium-catalyzed hydrogenations of the nitroolefins IV and XIII gave results that were similar to each other but different from those obtained in the β-series. Besides the expected saturated nitro glycosides with α-d-arabino (V) and α-d-lyxo (XV) configurations, two oximes (VI and XIV) were produced in yields of 49 and 30%, respectively. This may be attributed to a measure of steric interference by the glycosidic methoxyl group during the hydrogenation of the olefinic double bonds in IV and XIII. Amino glycosides were obtained from V and XV by debenzylidenation and platinum-catalyzed hydrogenation.
Naphth[2,3-d]imidazoline-2,4,9-triones
Authors: Truitt Price , Witkowski J. T.
Published: May 2006

1-Substituted naphth[2,3-d]imidazoline-2,4,9-triones have been prepared by the base-catalyzed cyclization of 1-benzoyl-3-(3-substituted-1,4-dihydro-1,4-dioxo-2-naphthyl)ureas and of 2-ethoxycarbonylamino-3-substituted-1,4-naphthoquinones.
Dissociation pressures of alcoholates of cobalt isothiocyanate
Authors: Pollak Peter , Cave G. C. B.
Published: May 2006

The systems Co(NCS)2 – methanol vapor and Co(NCS)2 – ethanol vapor have been studied. The known dialcoholates and also two previously unreported tetraalcoholates, were prepared. The dissociation pressures of the alcoholates were measured at several temperatures. Values of ΔH0 and ΔS0 at 25 °C were calculated for the reaction Co(NCS)2 + nROH = Co(ROH)n(NCS)2, with n = 2 and 4. Monoalcoholates were not found. A metastable system dialcoholate plus viscous blue liquid is discussed.
Transition metal complexes of 1-substituted tetrazoline-5-thiones
Authors: Agarwala Umesh , Narayan V. A. , Dikshit S. K.
Published: May 2006

Transition metal complexes of a number of 1-substituted tetrazoline-5-thiones have been prepared and their infrared spectra examined in the 3 600 – 500 cm−1 region. The analytical applications of 1-substituted tetrazoline-5-thiones for the gravimetric determination of cadmium and palladium have been studied.
Solvent effects on the proton spectra of some halopropenes. The preparation and proton resonance spectra of the 1-iodopropenes
Authors: Hruska F. , McBride D. W. , Schaefer T.
Published: May 2006

The preparation and proton resonance spectra of the 1-iodopropenes are reported and solvent effects on the proton spectra of the chloro-, bromo-, and iodo-compounds are measured. The proton coupling constants are discussed in terms of old and new electronegativity correlations. The olefinic cis and trans proton shifts can be attributed mainly to a paramagnetic contribution from the substituent, whereas the gem olefinic proton shifts depend in addition on the electron-withdrawing power of the substituent. The methyl proton shifts in the 1-substituted compound show little dependence on the substituent and this is discussed in relation to the barrier heights to methyl rotation. The solvent shifts in benzene cannot be completely reconciled with a dipole – induced dipole model. They increase with the size of the substituent and are largest for protons farthest from the substituent. The solvent shifts in acetone can be explained as due to weak hydrogen bonding and reaction field effects. The shifts of protons gem to the substituent arise mainly from hydrogen bonding, whereas the shifts of protons cis or trans have significant contributions from both effects. The reaction field effects can also account for the methyl shifts in acetone.
System triethylamine–water: the equilibrium diagram and some physical properties
Authors: Kartzmark E. M.
Published: May 2006

The freezing-point diagram, determined by the method of thermal analysis, corroborates the existence of a dihydrate, first discovered by Pickering (1). Density and viscosity measurements at 16.0 °C, slightly below the critical solution temperature of 18.3 °C, show marked non-ideality. The negative volume of mixing reaches a maximum at 50 mole % and the maximum in the viscosity (4.00 relative to water) occurs at 12 mole %.
The preparation of 3-alkylthio-2-methoxytetrahydropyrans
Authors: Baldwin M. J. , Brown R. K.
Published: May 2006

The reaction of alkylsulfenyl chlorides with 3,4-dihydro-2H-pyran, followed by treatment of the product with sodium methoxide, gave, highly stereoselectively, trans-3-alkylthio-2-methoxytetrahydropyrans. Purification by distillation under a vacuum at temperatures above 55° resulted in the elimination of methyl alcohol to produce 5-(alkylthio)-3,4-dihydro-2H-pyrans in a good yield. At lower temperatures, the more volatile homologues could be distilled undecomposed, but these had undergone thermal isomerization to a mixture of cis- and trans-3-alkylthio-2-methoxytetrahydropyrans. The conformational preference of these isomers is discussed.
The γ-radiolysis of cysteine in deaerated 1 N HClO4 solutions
Authors: Wilkening Verna Gaye , Lal Manohar , Arends Meta , Armstrong David A.
Published: May 2006

The G values for the formation of H2, H2S, alanine (CyH), and cystine ((CyS)2) in the 60Co γ-radiolysis of 10−3 and 10−2 M solutions of cysteine (CySH) in 1 N perchloric acid at 23 °C have been determined. They are quantitatively consistent with the following reaction mechanism.

[Formula: see text]The yields of H2 and H2S have also been measured at 1 ± 1°C. If H atoms are assumed to be the only reducing species in 1 N perchloric acid, k1/k2 was found to be 3.5 at 23 °C and 8 at 1 °C.
Peptides de l'acide djenkolique. I. Quelques dérivés symétriques et dissymétriques de l'acide djenkolique
Authors: Marinier Bernard , Penev Penio
Published: May 2006

not available
Cyclisation intramoléculaire des acides benzyl-2 pentène-4 oïques. Préparation de quelques tétraméthylnaphtalènes
Authors: Canonne P. , Regnault A.
Published: May 2006

The cyclization of 2-benzyl-4-pentenoic acids, catalyzed by protonic and Lewis acids, resulted in the formation of variable quantities of α-benzyl-γ-valerolactones and tetrahydronaphthalenecarboxylic acids (65 – 85%) which, after reduction and dehydrogenation, yielded tetramethylnaphthalenes substituted in the 1,3-positions. 1,3,5,7-Tetramethylnaphthalene, in particular, had not as yet been described. Aluminium chloride favors cyclization and does not give rise to lactonization, but it induces secondary reactions such as the migration of methyl groups.
Concurrent ion–molecule reactions. III. Reactions in mixtures of HCl and HCN with D2 and CD4
Authors: Harrison A. G. , Thynne J. C. J.
Published: May 2006

The concurrent ion–molecule reactions in mixtures of HCl and HCN with D2 and CD4 have been studied by the ratio plot method. The following reactions have been detected in mixtures with HCN and their cross sections determined at 10.5 V cm−1 repeller field strength.

[Formula: see text]In mixtures of D2 and CD4 with HCl the following reactions have been detected and cross sections determined.

[Formula: see text]Rate constants for the self-reactions in HCN and HCl have been measured both at 10.5 V cm1 repeller field and at thermal ion energies.
Ionization potentials of ammonia
Authors: Frost D. C. , McDowell C. A. , Vroom D. A.
Published: May 2006

The kinetic energy spectrum of photoelectrons ejected from ammonia by monochromatic 584 Å (21.21 eV) radiation has been determined using a spherical grid energy analyzer. Ionization potentials of 10.35 and 14.95 eV have been deduced from the spectrum and the relative transition probabilities to the ionic states have been measured. These experimental results are discussed in terms of the various molecular orbital theoretical treatments of the electronic structure of the ammonia molecule.
Crystal structure of cesium methylsulfonate, CsCH3SO3
Authors: Brandon J. K. , Brown I. D.
Published: May 2006

Cesium methylsulfonate, CsCH3SO3, crystallizes in space group Pnma with a = 9.526, b = 6.264, and c = 8.692 Å. Three-dimensional X-ray diffraction data have been collected photographically and refined to give a weighted agreement index (R) of 0.12. The structure is related to, but is not identical with, that of the isoelectronic compound barium sulfate. The CH3SO3− ion has C3v symmetry within the accuracy of this analysis, with S—O = 1.47 ± 0.02, S—C = 1.85 ± 0.04 Å (corrected for thermal motion), O—S—O = 112 ± 1°, and O—S—C = 107 ± 2°. The cesium ion is surrounded by nine oxygen atoms (Cs—O between 3.12 and 3.35 Å) and one methyl group (Cs—C = 3.77 Å).
Diterpene chemistry. II. The preferential oxidation of the vinyl groups of pimaric and sandaracopimaric acids
Authors: ApSimon J. W. , Chau A. S. Y. , Craig W. G. , Krehm H.
Published: May 2006

The use of the Lemieux – von Rudloff technique for the oxidation of the vinyl groups of pimaric (Ib) and sandaracopimaric (IIb) acid methyl esters has been investigated. Although the process leads to the expected C-13 acid V in the case of methyl sandaracopimarate, an unexpected epoxy acid was obtained from methyl pimarate. This product was shown to be the 8β,14β-epoxy-13-α-ketoacid VIIIa, probably arising from an intramolecular process during oxidation of the vinyl group.
Substitution of acyclic sugar acetals. Perchloric acid catalyzed acetolysis of poly-O-acetyl acyclic oxygen and sulfur acetals and epimerization of monothioacetals
Authors: Kurihara Norman H. , Painter Edgar Page
Published: May 2006

The rate constants are reported for the substitution of acyclic sugar poly-O-acetyl diethyl dithioacetals, poly-O-acetyl diethyl acetals, and poly-O-acetyl dimethyl acetals and for the epimerization of poly-O-acetyl S-ethyl monothioacetals when catalyzed by perchloric acid in acetic acid. All the reactions are pseudo first order. Monothioacetals substitute faster than oxygen acetals, and oxygen acetals substitute faster than sulfur acetals. A group bonded to C1of these acyclic sugar derivatives is substituted faster than when the group is bonded to C1of poly-O-acetyl pyranose derivatives.
Substitution of acyclic sugar acetals. Is the acid-catalyzed substitution of erythro and threo l,2,3,4,5-penta-O-acetyl-l-arabinose S-ethyl monothioacetals anchimerically assisted?
Authors: Painter Edgar Page , Kurihara Norman H.
Published: May 2006

The rate constants for the inversion and for the 14C-acetoxy exchange of the diastereomeric 1,2,3,4,5-penta-O-acetyl S-ethyl monothioacetals show that the substitution is not anchimerically assisted by the C2-acetoxy group. The substitution of acyclic poly-O-acetyl sugar monoacetals is best explained by the formation of the acyclic intermediate

[Formula: see text] (X = S or O) in the rate-determining step.
The role of added pyridine in substitution reactions of triphenylmethyl chloride in benzene solution
Authors: Leffek K. T. , Waterfield R. G.
Published: May 2006

A detailed kinetic investigation has been made of the specific role of pyridine when added to the methanolysis and radiochloride exchange reactions of triphenylmethyl chloride in benzene. It is concluded that neither of the two proposals in the literature, i.e. that it reacts with the alkyl halide to form a quaternary ammonium salt or that it has no effect whatever except to take up the hydrogen chloride product, is correct. The present results indicate that pyridine forms a complex with the triphenylmethyl chloride, without strong covalent bonding, which has a distinctive effect on the kinetics of the reactions.
Hydroformylation of glycals
Authors: Rosenthal A. , Abson D. , Field T. D. , Koch H. J. , Mitchell R. E. J.
Published: May 2006

Hydroformylation of 3,4-di-O-acetyl-d-xylal gave 4,5-di-O-acetyl-2,6-anhydro-3-deoxy-aldehydo-d-lyxo-hexose (I) and 4,5,di-O-acetyl-2,6-anhydro-3-deoxy-aldehydo-d-xylo-hexose (II). Methyl sulfoxide oxidation of 2,3-di-O-acetyl-1,5-anhydro-4-deoxy-d-arabino-hexitol (III) and of 2,3-di-O-acetyl-1,5-anhydro-l-xylo-hexitol (IV) yielded compounds I and II, respectively.Reaction of 3,4,6-tri-O-acetyl-d-glucal with carbon monoxide and hydrogen under carefully controlled conditions yielded 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-aldehydo-d-manno-heptose (VII) and 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-aldehydo-d-gluco-heptose (VIII) in a 70% yield. Compound VII was readily separated from the mixture of aldoses and alditols by column chromatography. Alternatively, aldoses VII and VIII were separated via their 2,4-dinitrophenylhydrazones. The conversion of aldoses VII and VIII into their diethyl dithioacetal derivatives is also described.The formyl group located in an equatorial orientation was found to be reduced at a faster rate than its axial counterpart.
Synthèse d'acides poly-α-aminés marqués au 14C
Authors: Normand André , Berlinguet Louis
Published: May 2006

Polymers and copolymers of 1-aminocyclopentanecarboxylic acid and l-lysine have been synthesized. The method has been adapted for the preparation of labelled polymers of 1-aminocyclopentanecarboxylic acid containing 14C on the carbonyl group.
The synthesis and properties of some dithiosemicarbazones
Authors: Wiles D. M. , Gingras B. A. , Suprunchuk T.
Published: May 2006

A series of new compounds has been prepared by reacting aliphatic and aromatic aldehydes with ethylene dithiosemicarbazide. The nature of these new dithiosemicarbazones has been deduced from their infrared spectra, from the products of the ferric chloride induced oxidation of two of them, and from the formation of 1:1 copper complexes of several of them. Since the copper complexes are paramagnetic, the copper must be present in the cupric oxidation state. A structure has therefore been proposed for the complexes which involves bonding between copper and both thiocarbonyl groups in the dithiosemicarbazone molecule.Several of the compounds prepared in this work exhibit an antifungal action against the cellulolytic microorganism Chaetomium globosum.
Theoretical views on Szilard Chalmers reactions in solid systems. I. Parent reformation by an extreme back-diffusion mechanism
Authors: Wiles D. R. , Wong W.-H.
Published: May 2006

This paper considers parent reformation in molecules in which the central atom recoils at high energy, following neutron capture. It is postulated that parent reformation following diffusion of the recoil atom back to the initial site can be successful only if the recoiling atom does not cause serious damage to the ligand structure. By using the Bohr screened potential, the probability of ligand-structure damage has been calculated and found to be negligible. The results are compared with experimental data. Although the comparison is not straightforward, the widespread lack of correspondence leads to the conclusion that back diffusion as postulated plays a minor role, if any, in parent reformation in the cases studied. An important conclusion reached from these calculations is that the probability of such damage is not very sensitive to uncertainties in the initial recoil energy.
Anionic polymerization of isoprene. Ion and ion-pair contributions to polymerization in tetrahydrofuran
Authors: Bywater S. , Worsfold D. J.
Published: May 2006

The kinetics of the propagation reaction in the polymerization of isoprene initiated by butyllithium in tetrahydrofuran solution have been studied. The kinetic behavior has indicated that the reactive species involves both the polyisoprenyllithium ion-pair and the free poly-isoprenyl carbanion. The conductances of solutions of polyisoprenyllithium have been measured and the ionic dissociation constant derived. From these the free ion rate constant has been evaluated. It has also been shown that the free ion reaction may be suppressed by the common ion effect when the salt lithium tetraphenylboron is added. The rate constants for the ion-pair and free ion are 0.20 M−1 s−1 and 2.8 × 103 M−l s−1 respectively; the ionic dissociation constant is 5.0 × 10−10. Nuclear magnetic resonance determinations of the structures of the polymers formed primarily by the free carbanion, and by the ion-pair only, show that the lithium ion has only a small directing effect.
Diffusion in multicomponent gaseous mixtures. Part 3
Authors: Watts Harry
Published: May 2006

Diffusion of one rare gas into an equimolar mixture of two other rare gases has been followed using krypton-85 or xenon-133 tracer. The systems behave as pseudo-binary diffusion systems. A kinetic theory equation, valid for diffusion of a trace in a multicomponent mixture, is not a good approximation for diffusion of a major component.
The hydrolysis of some N-benzoylamino acids in dilute mineral acid
Authors: Capindale J. B. , Fan H. S.
Published: May 2006

The behavior of N-benzoylaspartic acid and N-benzoylglutamic acid has been investigated at 100° in dilute solution in water and aqueous hydrochloric acid within the pH range 3.1–0.5. Some data are presented concerning the hydrolysis of the N-benzoyl derivatives of alanine, β-alanine, leucine, glycine, serine, and β-ethanolamine in water, 0.1 N hydrochloric acid, and 2 N hydrochloric acid. Benzoylglutamic acid undergoes a pH-independent conversion into pyrrolid-2-one-5-carboxylic acid, which then hydrolyses in mineral acid to glutamic acid; however, N-benzoylaspartic acid, under similar conditions, hydrolyses much more rapidly by a route which does not involve the corresponding lactam as an intermediate. In anhydrous alcohols the solvolysis of N-benzoylaspartic acid gives mixtures of aspartic acid and the β ester.First-order rate constants have been obtained for the acid-catalyzed hydrolysis of pyrrolid-2-one-5-carboxylic acid (I) and azetidin-2-one-4-carboxylic acid (II) in water over this pH range.
Acylation products of 5,5-diphenylimidazolid-4-one
Authors: Edward J. T. , Lantos I.
Published: May 2006

Acylation of 5,5-diphenylimidazolid-4-one gives 1,3-diacyl-5,5-diphenylimidazolid-4-ones, and not 2-acyl-4,4-diphenyl-2,5-diaza-7-oxabicyclo[3.2.0]heptan-3-ones as claimed by Biltz and his co-workers. The reason for the unusual stability of the N1-acyl groups to acid and alkaline hydrolysis is discussed. The revised formulation allows the oxidation products of 1-acetyl-5,5-diphenylimidazolid-4-one to be rationalized in a simple fashion.
Electrochemical reactions at PbO2 electrodes. Part I. The passivation of β-PbO2 in perchloric acid
Authors: Hampson N. A. , Jones P. C. , Phillips R. F.
Published: May 2006

The cathodic passivation of β-PbO2 electrodes in electrolytes based on perchlorate ion has been studied as a function of current density and electrolyte composition.Before passivation the electrode remains free of films based on Pb(II).Passivation results are correlated in the form of a modified diffusion equation incorporating two parameters kp and i1.

[Formula: see text]
Single and double electronic transitions in molecular oxygen
Authors: Whitlow S. H. , Findlay F. D.
Published: May 2006

The emission bands at 6 340 Å and 7 030 Å in the spectrum of excited molecular oxygen, believed to be due to the "dimol" O4*(1Δg, 1Δg), have been investigated with respect to the dependence of their intensities on the excited oxygen concentration. The intensities of these bands have been shown, by a comparison with the intensity of the (0,0) band of the (1Δg – 3Σg−) system at 12 700 Å, to depend on the square of the O2(1Δg) concentration. The ratio of the intensities of the two visible bands at 6 340 Å and 7 030 Å was found to be 1.05 ± 0.1.An attempt was made to resolve the 6 340 Å and 12 700 Å bands into their rotational fine structure. The results show that, whereas the 12 700 Å band could be at least partially resolved, the 6 340 Å band appeared to be diffuse with a band half-width of 150 Å.Evidence is presented of vibrational excitation in the 1Σg+ state of molecular oxygen in the discharged products.
Addition of alkoxide ions to alkenes. The HR– scale
Authors: Kroeger D. J. , Stewart Ross
Published: May 2006

By using α-cyanostilbenes as Lewis acids, Lewis acidity scales have been established in ethanolic and methanolic dimethyl sulfoxide containing the appropriate 0.01 M sodium alkoxide and in the system sodium methoxide – methanol. This scale, designated

[Formula: see text], describes the ability of the solvent to add an alkoxide ion to an alkene. The

[Formula: see text] values range from 11.73 in methanol to 21.74 in 93.27 mole % dimethyl sulfoxide in ethanol.The most acidic indicator used to establish the scale was α-cyano-2,4-dinitrostilbene, with a pKA of 12.73 in dimethyl sulfoxide – methanol. The least acidic was α-cyano-3-trifluoro-methylstilbene, with a pKA of 21.98 in dimethyl sulfoxide – ethanol.The increase in the system's ability to add alkoxide ion to the cyanostilbenes as the dimethyl sulfoxide concentration rises is ascribed chiefly to its effect on the activity of the alkoxide ion. The functions H− and

[Formula: see text], unlike their analogues in acid systems (H0 and Hr), do not diverge greatly as the concentration of the hydroxylic solvent component is decreased.
A nuclear magnetic resonance study of exchange reactions in the system boron trifluoride – methanol. A modified interpretation
Authors: Gillespie R. J. , Hartman J. S.
Published: May 2006

The proton magnetic resonance spectra of boron trifluoride – methanol solutions in sulfur dioxide, with methanol in excess, are interpreted in terms of equilibria between methanol, methanol·BF3, and (methanol)2·BF3. The two methyl peaks observed in the spectra at low temperatures may be attributed to methyl groups in free and complexed methanol (i.e. methanol in which the oxygen is coordinated by BF3).
Correlation of absorption spectra and structure of some Co(II)– and Ni(II)–2,2′-biquinoline complexes
Authors: Faye G. H. , Horwood J. L.
Published: May 2006

Co(II)– and Ni(II)–2,2′-biquinoline (Biq) complexes of the type MBiqCl2 and MBiq(NO3)2 have been isolated. Electronic absorption spectra in the visible and near infrared, as well as magnetic measurements, show that CoBiqCl2 is essentially tetrahedral, whereas NiBiqCl2 and the MBiq(NO3)2 complexes are pseudo-octahedral. In acetone solution Co(II) forms a bis-Biq complex that is probably five coordinate, whereas the Ni(II) analogue is probably an octahedral species with a cis configuration. Elementary ligand field theory has been used to interpret the absorption spectra, and certain electronic transition assignments have been made that may be of general interest.
General base catalysis in the iodination of adrenochrome
Authors: Mattok G. L. , Wilson D. L.
Published: May 2006

The iodination of adrenochrome by iodine is subject to general base catalysis. This is in accord with the view that the rate-determining step in this reaction is the removal of the C-7 proton in the adrenochrome. The order of catalytic activities of the various ions is phosphate > bicarbonate > propionate > acetate, which is also the sequence of the pKa values of the corresponding acids. However, the catalytic efficiencies of the hydrogen phthalate and phthalate anions are about 10 times greater than those predicted from the dissociation constants of the acid. This is rationalized in terms of an alternative electrophilic–nucleophilic catalysis of the iodination reaction.
Conformational analysis of trans-1,4-dihalocyclohexanes
Authors: Wood Gordon , Woo E. P.
Published: May 2006

The conformational equilibria of trans-1,4-dibromo- (I), trans-1,4-dichloro- (II), and trans-1,4-bromochloro-cyclohexane (III) were determined by integration of the separate axial and equatorial proton signals at low temperature. The

[Formula: see text] values for compounds I, II, and III were found to be approximately 200 cal/mole.
Syntheses of the alkali metal borodeuterides
Authors: Atkinson J. G. , MacDonald D. W. , Stuart R. S. , Tremaine P. H.
Published: May 2006

A synthesis of sodium borodeuteride on a molar scale has been developed. Trimethylamineborane was exchanged (6) with deuteriosulfuric acid in deuterium oxide to obtain trimethylamineborane-d3 of a high isotopic purity. Reaction of trimethylamineborane-d3 with sodium methoxide in diglyme at 120–150 °C yielded sodium borodeuteride, which, after purification, was obtained in a 40–50% overall yield. The conditions for obtaining material of a high isotopic and chemical purity were found to be rather stringent but, once worked out, were easily reproducible.Lithium borodeuteride and potassium borodeuteride were also prepared from trimethylamineborane-d3 and the corresponding methoxide salts. An alternative synthesis of lithium borodeuteride, involving the reaction between lithium deuteride and boron trifluoride etherate, was found to be more satisfactory, since it avoided the formation of stable 1:1 solvent complexes with lithium borodeuteride.The products that were obtained had a chemical purity of 97%, and contained 98–99 atom % deuterium. The deuterium analyses were performed by reducing a series of ketones containing no α hydrogens and analyzing the secondary alcohol by nuclear magnetic resonance for residual hydrogen on the alcohol carbon.
Amino acid radicals produced chemically in aqueous solutions. Electron spin resonance spectra and relation to radiolysis products
Authors: Armstrong W. A. , Humphreys W. G.
Published: May 2006

Amino acid radicals were generated by the reaction of titanium trichloride with hydrogen peroxide in the presence of an amino acid, and were identified by electron spin resonance spectroscopy. An amino acid analyzer was used to show that the products of this reaction were the same as those of the corresponding γ-irradiated, oxygenated aqueous amino acid solution. Cysteine, cystine, and homocystine gave identical spectra which were attributed to

[Formula: see text]·radicals, whereas penicillamine gave

[Formula: see text]·radicals. Most other amino acid radicals were formed by the abstraction of a hydrogen atom from the C2 position (numbered from the amino group). This was true for dl-α-alanine, β-alanine, taurine, dl-aspartic acid, γ-aminoisobutyric acid, dl-serine, and dl-valine, although with valine a lower concentration of the radical resulting from the removal of a hydrogen atom from C3 was also observed. Abstraction from the C3 position also occurred with dl-threonine. These facts are consistent with the view that the strong negative inductive effect of the NH3+ group deactivates the neighboring C—H bond towards attack by the electrophilic hydroxyl radical. Glycine formed one radical by the loss of a hydrogen atom from the C1 position, and a second by deamination.
Decomposition pressures and enthalpies of formation of some transition metal diarsenides and diselenides
Authors: Murray J. J. , Heyding R. D.
Published: May 2006

The phase relations for the systems Pt/As, Os/As, Os/Se, and Ru/Se have been examined in the range 850–1 250 °K. Using the torsion effusion method, the decomposition pressures of PtAs2, OsAs2, OsSe2, and RuSe2 have been measured as a function of temperature. The apparatus and procedures were verified by measuring the vapor pressure of liquid silver. Equilibrium pressures were obtained for PtAs2 and RuSe2. OsAs2 exhibited an orifice area dependent nonequilibrium behavior and OsSe2 exhibited a time dependent nonequilibrium behavior. Equilibrium pressures were estimated in these latter two cases. Total equilibrium decomposition pressures (Pt), i.e. the pressure of arsenic or selenium vapors in equilibrium with each phase, are best described by the equations:

[Formula: see text]Literature data on the equilibria between the various molecular species in selenium and arsenic vapor indicate that at these pressures and temperatures the vapor in equilibrium with the selenides is essentially pure Se2, but the vapor over the arsenides is a mixture of As2 and As4.The heats and entropies of decomposition of PtAs2, OsAs2, OsSe2, and RuSe2 have been calculated from the decomposition pressure data. The standard heats of formation at 298 °K are −42.0 ± 3.5, −18.5 ± 2.0, −32.5 ± 5.0, and −42.9 ± 3.5 kcal/mole, respectively. Heats of formation of MnSe2, CoSe2, NiSe2, and RhSe2 have been estimated using the heats of formation of OsSe2 and RuSe2, the Born–Mayer equation, and the Born–Haber cycle. These are −96 ± 8, −70 ± 8, −41 ± 8, and −12 ± 12 kcal/mole, respectively.