bluuebunny/crossref_metadata_2025 huggingface dataset:
Arsinohydrazines: reactions of hydrazine and substituted hydrazines with organo-arsine derivatives
Authors: Peterson L. K. , Thé K. I.
Published: May 2006

Reactions between organo-arsine derivatives (CF3)2AsX and (CF3)3As and hydrazine or substituted hydrazines are discussed as synthetic routes to a new class of hydrazinoarsine compounds. The systems [(CF3)2As]x N2H4−x are unstable with respect to elimination of CF3H and N2, but stability increases with increased methylation of the nitrogen atoms. The new compounds described are: N-methyl, N′-bis(trifluoromethyl)arsinohydrazine, MeNHNHAs(CF3)2, (1) (highly unstable at room temperature); N,N-dimethyl, N′-bis(trifluoromethyl)arsinohydrazine, Me2NNHAs(CF3)2, (2) (m.p. 3.00° ± 0.15°, b.p. 20°/14.6 mm); and trimethylhydrazino-bis(trifluoromethyl)arsine, Me2NNMeAs(CF3)2, (3) (m.p. −41.5° ± 0.5°, b.p. 15°/6.30 mm). The observed order of stability was [Formula: see text]
Catalytic hydrodesulfurization of thiophene. VII. Comparison between thiophene, tetrahydrothiophene, and n-butanethiol
Authors: Kolboe S.
Published: May 2006

The desulfurization rates in hydrogen of thiophene, tetrahydrothiophene, and n-butanethiol over molybdenum disulfide, an alumina supported cobalt molybdate, and a chromia catalyst have been measured.Measurements of the interconversion rates of the three sulfur compounds were also carried out.
Specifically ring-labelled (±)-pelletierine
Authors: Gupta R. N. , Spenser Ian D.
Published: May 2006

A synthesis of 2-14C- and of 6-14C-(±)-pelletierine and (±)-α-phenacylpiperidine is described, starting from 2-14C- and 6-14C-(±)-lysine, respectively.
Photolysis of a diterpene nitrosamine
Authors: Watkins W. B. , Seelye R. N.
Published: May 2006

Photolysis of the diterpene nitrosamine, 4-N-nitroso-4-N-methyl-12-methoxy-16-norpodocarpa-8,11,13-trien-4-amine in cyclohexane solvent gave the corresponding amine as the major product.
Preparation of diphenylamines via the Chapman rearrangement
Authors: Wheeler Owen H. , Roman Fernanda , Santiago Marcelina V. , Quiles Francisco
Published: May 2006

The optimum conditions have been determined for preparing substituted diphenylamines using the Chapman rearrangement. The rearrangement was best carried out in boiling tetraglyme. Phenyl N-phenylcinnamidate rearranged at a lower temperature than the corresponding benzimidate.
Synthesis of some para-substituted 3,3,3-triarylpropionic acid derivatives
Authors: Adley T. J. , Clarke D. R.
Published: May 2006

The syntheses of representative compounds of the type 4-XC6H4(4′-YC6H4)C6H5CCH2CO2R are described.
Total synthesis of the Ormosia alkaloid skeleton
Authors: Liu H. J. , Valenta Z. , Wilson J. S. , Yu T. T. J.
Published: May 2006

A total synthesis of dilactam (3) possessing the complete pentacyclic skeleton of the Ormosia alkaloids has been completed.
Mass spectrometric studies of chemical reactions in shock waves: the thermal decomposition of nitrous oxide
Authors: Barton S. C. , Dove J. E.
Published: May 2006

Apparatus for the mass spectrometric study of rapid gas reactions in reflected shock waves is described. This apparatus has been applied to the thermal decomposition of 2% N2O in Kr at total gas concentrations of about 1.6 × 10−6 mole cm−3, in the temperature range 1800 to 2800 °K. The principal products of the reaction were found to be N2, O2, NO, and O. The rate coefficient for the unimolecular decomposition of N2O was calculated from the experimental data, and the rates of the secondary reactions between O and N2O were estimated. The possibility of the occurrence of a "weak collision" mechanism in the unimolecular reaction of N2O is discussed.
Conductance and viscosity of n-alkylamine hydrobromides in water at 25 °C: influence of hydrophobic hydration
Authors: Desnoyers Jacques E. , Arel Marcel , Leduc Paul-André
Published: May 2006

The equivalent conductivities and viscosities of the homologous salts RNH3Br, where R varies from H to n-octyl, have been measured in water at 25 °C. The data in the submicellar region can be represented adequately by the semi-empirical relations[Formula: see text]The parameters Bη+ and λ0+ are both functions of the effective size of the organic ions in solutions, while the parameters Dη and BΛ can be interpreted through structural salting-in of the hydrophobic cations. Viscosities and conductivities can be used equally well to study the micelle formation of n-octylamine hydrobromide.
A theory of circular dichroism
Authors: Lawetz V. , Hutchinson D. A.
Published: May 2006

An expression for circular dichroism is derived by a method in which the radiation field, in addition to the molecules, is quantized. From the total scattering cross sections for right and for left circularly polarized photons, the respective absorption coefficients are determined. A formula for the circular dichroism is obtained from the difference between the absorption coefficients. The present result is in agreement with the semi-classical result of Condon, Altar, and Eyring.
Normal coordinate analysis of dialkyldithiocarbamate and its selenium analogue
Authors: Durgaprasad G. , Sathyanarayana D. N. , Patel C. C.
Published: May 2006

The infrared spectrum of N,N-dimethyldithiocarbamate complex of nickel(II) has been recorded in the range 2000–250 cm−1. Normal coordinate analyses have been made for nickel dimethyldithiocarbamate and nickel dimethyldiselenocarbamate complexes and their infrared spectra indexed. The frequency shifts observed on alkyl substitution have been discussed. The M—Se stretching frequency occurs about 100 cm−1 lower in the diselenocarbamate complex as compared to M—S frequency of the dithiocarbamate.
Thermochemistry of the aqueous manganous ion
Authors: Gedansky L. M. , Hepler L. G.
Published: May 2006

Heats of solution of MnSO4(c) have been measured and combined with heats of dilution to yield ΔH0 = −15.3 kcal/mole for the standard heat of solution. This value leads to ΔHf0 = −52.9 kcal/mole for Mn2+(aq). Calculations with data from the literature give ΔGf0 = −55.1 kcal/mole for Mn2+(aq). Combination of this value with our ΔHf0 gives [Formula: see text] for Mn2+(aq). Our ΔHf0 value for Mn2+(aq) is compared with other values derived from calculations based on data taken from the literature.
Meisenheimer complexes of some 1-substituted-3,5-dinitrobenzenes
Authors: Foreman M. I. , Foster R.
Published: May 2006

It has been shown by nuclear magnetic resonance spectroscopy that both 3,5-dinitrobenzonitrile and 3,5-dinitrobenzotrifluoride form Meisenheimer-type σ-complexes with various nucleophiles in solution. In some cases attack appears to occur at both the 2- and 4-positions.
Anisotropic effects on proton magnetic resonance frequencies of substituted barbituric acids
Authors: Neville George A. , Cook Denys
Published: May 2006

Several pharmacologically important barbituric acids were examined by proton magnetic resonance spectroscopy in trifluoroacetic acid, p-dioxane, and dimethyl sulfoxide-d6. The data obtained greatly facilitate identifying and distinguishing barbiturates. Variations in chemical shift with alkyl substitution have been discussed, and the suggestion has been put forward that—the CH3(Et) protons may be a sensitive probe for detecting changes in anisotropy (both ring and C=O) in a series of barbiturates. Evidence for the preferred configuration of C-5 phenyl, ethyl, and isopropyl substituents was obtained. Concentration studies by both proton magnetic resonance and infrared spectroscopy indicate that the barbiturates examined exist predominantly as solvated monomers rather than as dimers or oligomers.
Reaction of propionaldehyde with N′-methyl-2,6-dimethylphenylhydrazine hydrochloride. The dienone–imine intermediate in the Fischer indole synthesis and its conversion to the indole structure
Authors: Bajwa G. S. , Brown R. K.
Published: May 2006

When N′-methyl-2,6-dimethylphenylhydrazine hydrochloride was condensed with propionaldehyde by azeotropic removal of water in refluxing benzene for 10–12 min, a solid mixture was obtained which contained no aromatic ring system but instead possessed features indicative of a dienone–imine structure. When this mixture, or the original combination of N′-methyl-2,6-dimethylphenylhydrazine hydrochloride and propionaldehyde, was heated in refluxing benzene for 20 h there was obtained 1,3,7-trimethylindole in 36 and 31% yield respectively. Evidence indicated that a substantial amount of 3,7-dimethylindole was also produced.The results support the view that an intermediate dienone–imine is formed as one step in the Robinson mechanism of the Fischer indole synthesis.
Mass spectrometry of ozonides
Authors: Castonguay J. , Bertrand M. , Carles J. , Fliszár S. , Rousseau Y.
Published: May 2006

The mass spectra of some ozonides are reported, and the modes of formation of the major fragment ions tentatively described. The use of 18O-labelled compounds has proven to be useful in establishing fragmentation patterns. It is concluded that these follow a characteristic path, which is common to all the ozonides studied and permits mass spectrometric identification.
On the in-plane vibration frequencies of the vinylidene, d1-, and d2-vinylidene halides. I. Force fields and normal modes. II. Characteristic group vibrations
Authors: Freeman J. M. , Henshall T.
Published: May 2006

An investigation has been undertaken of the characteristic in-plane group vibrations of the vinylidene and d2-vinylidene groups from the viewpoints both of approximation methods of the vibrational analysis of, and aids to assignments in, molecules containing such groups.The need in these studies for reliable force fields for the vinylidene halides has caused us to undertake a normal coordinate analysis of the in-plane vibrations of these molecules using a modified valence force field, and including all the available information from the hydrogen and deuterium isotopically substituted species.
Preparation of β-rhenium tetrachloride
Authors: Frais P. W. , Guest A. , Lock C. J. L.
Published: May 2006

β-Rhenium tetrachloride has been prepared by three different methods. Infrared, magnetic, and X-ray powder diffraction data are reported.
Conversion of tetracyclic triterpenes to steroids
Authors: Pettit George R. , Dias Jerry R.
Published: May 2006

An alternative procedure for converting the typical 3-hydroxy-4,4-dimethyl-substituted triterpene A-ring to a steroidal 3-oxo-4-ene system has been outlined. Application of the new method to 3β-hydroxy-5α-lanostane (1) was used for illustration. Key reaction steps involved Baeyer-Villiger oxidation of ketone 3 to lactone 4 and the latter to carboxylic acid 5 employing Jones' reagent. Proceeding via enol–lactone (6) and diketone (7) led to 3-oxo-14α-methyl-cholest-4-ene (8). The first example of an oxa-14α-methyl-steroid was also reported.
Thermal and photolytic decomposition of N-benzhydrylidene azidobenzhydrylamine
Authors: Koga N. , Koga G. , Anselme J.-P.
Published: May 2006

The thermal and photolytic decomposition of N-benzhydrylidene azidobenzhydrylamine (2) in aromatic solvents gave N-phenyl-N′-benzhydrylidene benzamidine (5); no benzophenone azine could be isolated. Photolysis in methanol gave no 5 but instead benzophenone dimethylketal and ammonium azide were obtained. Attempts to trap the presumed nitrene intermediate with cyclohexene gave only 5. Thermal decomposition in decalin gave N-benzhydryl benzophenone imine (9). The possible mechanisms of these transformations are presented.
Partial asymmetric synthesis of methylenecyclopropanes and spiropentanes
Authors: Noyori R. , Takaya H. , Nakanisi Y. , Nozaki H.
Published: May 2006

Reaction of substituted allenes and diazomethane gives rise to optically active methylenecyclopropane and spiropentane derivatives in the presence of dissymmetric copper chelates, bis[N-(R and S)-α-phenethylsalicylaldiminato]copper(II).
Monomer and dimer formation in esters of dihydroxyacetone
Authors: Garson Lorrin R. , Quintana Ronald P. , Lasslo Andrew
Published: May 2006

The monomer (1-undecanoyloxy-3-hydroxyacetone) and dimer (2,5-diundecanoyloxymethyl-2,5-dihydroxy-1,4-dioxane) of dihydroxyacetone monoundecanoate have been characterized, and the conditions associated with their interconversion have been determined. The respective molecular constitutions have been unequivocally documented with ultraviolet and infrared spectral characteristics.
An investigation of some iron halide complexes by Mössbauer spectroscopy
Authors: Birchall T.
Published: May 2006

The products of the reaction between iron carbonyls and various ligands have been examined by Mössbauer spectroscopy. With triphenylphosphine and triphenylarsine, complexes of Fe(III) in a tetrahedral configuration are produced. In all other cases the complexes contain Fe(II), and it is suggested that these are not monomeric, but are chlorine bridged complexes.
Effect of pressure on the rates of hydrolysis of allyl chlorides
Authors: Lateef A. B. , Hyne J. B.
Published: May 2006

The pressure dependence of the rates of hydrolysis of allyl chloride and α-, β-, and γ-methyl allyl chlorides has been examined. The significance of the activation volumes, ΔV*, and their pressure dependence, dΔV*/dP, is discussed. These activation parameters indicate an SN2 mechanism for allyl and β-methyl allyl chloride and an SN1 or intermediate character mechanism for the other methyl substituted allyl chlorides investigated. The results are compared with the corresponding ΔH* and ΔCP* measurements of Robertson and co-workers. The temperature dependence of the activation volume, dΔV*/dT, for the solvolysis of the parent allyl chloride has been measured and found to be small and negative.
Some new diphosphine-bridged nickel carbonyl and cyclopentadienyl compounds
Authors: Carty A. J. , Efraty A. , Ng T. W.
Published: May 2006

The binuclear diphosphine bridged monocarbonyl compound [Ni(CO)]2(DPPA)3 has been obtained by reaction of Ni(CO)4 with bis(diphenylphosphino)acetylene (DPPA) under mild conditions and by displacement of π-cyclopentadienyl groups from [π-C5H5Ni(CO)]2 at room temperature. The latter reaction suggests a possible route to other monocarbonyl nickel phosphine compounds not available by direct reaction of Ni(CO)4 with phosphines. The preparation and characterization of the binuclear compounds [Ni(CO)2]2(DPPA)2, [Ni(CO)3]2(DPPA), and (π-C5H5NiI)2(DPPA) are also described.
Tris(ethylenediamine)ruthenium(III) iodide
Authors: Watt George W. , Senoff C. V.
Published: May 2006

not available
Structures of yeast mnnans containing both α- and β-linked D-mannopyranose units
Authors: Gorin P. A. J. , Spencer J. F. T. , Bhattacharjee S. S.
Published: May 2006

Several mannans from yeasts give proton magnetic resonance spectra with distinctive H-1 signals at higher field than τ 4.55. A number of these mannans were investigated polarimetrically and each has a specific rotation corresponding to a mixture of α- and β-D-linkages. Four were partially hydrolyzed and shown to have most of the α-linkages in the main chains and the β-linkages in the side chains. Detailed structural investigations showed that the Pichiapastoris mannan probably has an α-(1→6)-D-manno-pyranosyl main-chain substituted in the 2-positions with a substantial proportion of O-α-D-mannopy-ranosyl-(1→2)-O-β-D-mannopyranosyl-(1→2)-O-β-D-mannopyranosyl-(1→2)-O-α-mannopyranosyl side-chains (1). The related mannan from Citeromycesmatritensis has a similar main-chain, which is substituted in the 2-positions by α-D-mannopyranosyl units and β-(1→2)-pyranose-linked D-mannotriosyl and perhaps mannobiosyl side-chains (2).
Preparation, absolute configuration, and thermolysis of (3R:5R)-(+)-trans-3,5-dimethyl-1-pyrazoline
Authors: Mishra Anupama , Crawford Robert J.
Published: May 2006

Thermolysis of (3R:5R)-(+)-trans-3,5-dimethyl-1-pyrazoline produces 25.6% of trans-1,2-dimethyl-cyclopropane of 23% optical purity having the S:S configuration. Thermolysis mechanisms which explain the racemization and the double inversion process are discussed. The absolute configuration of active-2,4-pentanediol and 2,4-dibromopentane is correlated with that of 4-hydroxy-1-pentene.
Secondary kinetic isotope effects in bimolecular nucleophilic substitutions. III. Deuterium effects in the Bunte salt reaction of methyl halides and sulfonates
Authors: Jackson G. E. , Leffek K. T.
Published: May 2006

Secondary kinetic deuterium isotope effects have been measured for the reaction between thiosulfate ion and methyl-d3 halides and sulfonates in 50% v/v ethanol–water. The results are used to extend the correlation of Seltzer of kH/kD with the difference between the polarizabilities of the attacking nucleophile and the leaving group.Dissociation constants for the [NaS2O3]− ion have been determined by conductivity measurements for the reaction conditions and used to calculate the concentration of free thiosulfate ions present in the reaction mixture. The activation parameters ΔH≠ and ΔS≠, based on second order rate constants calculated with respect to the concentration of thiosulfate ion, are reported.
Electron impact-induced rearrangements of acetylenic compounds
Authors: Aplin R. T. , Safe S.
Published: May 2006

The mass spectra of all-trans-hepta-2,4-dien-6-yn-1-ol (3) and all-trans-hepta-2,4-dien-6-yn-1-al (6) are remarkably similar to benzyl alcohol and benzaldehyde respectively. Comparison of α-d-all-trans-hepta-2,4-dien-6-yn-1-ol (5) and α-d-benzyl alcohol shows that the deuterium in the C7H7+ tropylium ion is randomized in both compounds.
Laboratory measurements of photoionization, photoexcitation, and photodetachment
Authors: Schoen Richard I.
Published: May 2006

This review is devoted to a discussion of laboratory measurements of ionization, fluorescence, and photodetachment. The review is limited to molecules of aeronomic interest but excludes atoms. The section on photodetachment includes only work which has appeared since 1964. Current data are presented on photoionization cross sections, dissociative ionization cross sections, cross sections for the excitation of particular states of ions, relative vibrational excitation probabilities, photodetachment cross sections, angular distributions of electrons from photoionization, and dissociative excitation of neutral molecules. Some suggestions are made for further work.
Comments, Replies, and Summary
Authors: Fontijn A.
Published: May 2006

not available
Pyridazino[4,5-b]indole derivatives
Authors: Nogrady Thomas , Morris Leeson
Published: May 2006

A series of pyridazino[4,5-b]indole lactams and their reduction products was prepared in an attempt to uncover monoamine oxidase inhibitory activity. The reduction and nuclear magnetic resonance spectra of these compounds are dealt with. Some are weak analgesics but no other pharmacological activity was found.
Mass spectral fragmentation of some bicyclic diketals. Evidence for ethylenedioxycarbene
Authors: Wood Gordon , Woo E. P.
Published: May 2006

Some evidence is presented for a novel mass spectral fragmentation of certain bicyclic diketals.
Complexes of Group IV halides with mercuric thiocyanate and mercuric cyanide as ligands
Authors: Jain S. C. , Rivest R.
Published: May 2006

Coordination compounds between mercuric thiocyanate and mercuric cyanide as ligands and the Group IV halides as Lewis acids have been prepared and their infrared (i.r.) spectra (4000–200 cm−1) examined. Two types of compounds, MX4•L and MX4•2L where M = Ti, Sn; X = Cl, Br; and L = Hg(SCN)2 or Hg(CN)2 were characterized. On the basis of i.r. spectral results, possible coordination through the thiocyanato and cyano groups has been discussed.
Crystal structure of β′Mn3(PO4)2
Authors: Stephens J. S. , Calvo C.
Published: May 2006

β′Mn3(PO4)2 crystallizes as a monoclinic crystal with lattice parameters a = 8.94(3) Å, b = 10.04(2) Å, c = 24.12(12) Å, β = 120.8(1)°, and Z = 12. The diffraction pattern shows a pronounced superlattice phenomenon with reflections generally weak if their l index ≠ 0 mod 3. The conventional R value for a total of 3516 reflections, of which 1637 were strong enough to be measured, was reduced to 0.09 by full matrix least squares procedures. This structure is related to that of βZn3(PO4)2 whose unit cell dimensions are comparable save for a tripled c axis in β′Mn3(PO4)2. In addition, the latter compound is isostructural with the low temperature form of Cd3(PO4)2. The PO43− groups are slightly irregular tetrahedra with a mean P—O bond distance of 1.54 ± 0.01 Å. The coordination numbers of the cations have increased on the average in comparison to βZn3(PO4)2 where they are 4, 5, and 5 for the three unique cations. In β′Mn3(PO4)2 each cation shows 5 strong Mn—O bonds and most cations have one additional bond of intermediate strength. The metal–oxygen atom bond distances in β′Mn3(PO4)2 range from 2.03 to 2.31 Å although there are some additional long ones ranging from 2.4 to 3.0 Å which can be correlated with normal bond lengths in βZn3(PO4)2.
Dielectric properties of hexafluoroacetone and hexachloroacetone
Authors: Chan R. K.
Published: May 2006

The dielectric constants of hexafluoro- and hexachloro-acetone are measured in the solid and liquid state. They show negligible association in the liquid state. The dipole moments are 0.648 D measured in the gaseous state and 0.63 D in pure liquid for hexafluoroacetone, and 1.24 D in carbon tetrachloride solution and 1.34 D in pure liquid for hexachloroacetone. If the differences between inductive effects due to CX3 and C=O groups can be ignored, the vector addition of bond moments gives values of dipole moment which are compatible with the experimental values.
Substitution reactions at octahedral centers. IV. Acid and base hydrolysis of chloropentakis(alkylamine)chromium(III) ions
Authors: Parris M. , Wallace W. J.
Published: May 2006

The compounds [Cr(RNH2)5Cl](ClO4)2, where R = H, CH3, C2H5, n-C3H7, and n-C4H9, have been prepared and the replacement of chloride by either water or hydroxide ion subjected to kinetic examination. Below about pH 7 the reaction was acid independent, and ΔHA* was 22.4 kcal mole−1 when ammonia was the inert ligand compared with about 26.4 kcal mole−1 when the inert ligand was a primary amine. The corresponding ΔSA* values increased continuously with R from H to n-C4H9. At higher pH the rate became inversely dependent upon the acidity of the solution, and ΔHB* decreased from 26.7 kcal mole−1 for ammonia as the inert ligand to 25.4 kcal mole−1 for an amine as the inert ligand. For the pH dependent reaction the values obtained for ΔSB* were much larger than for the pH independent reaction but the pattern of variation as the inert ligands were changed was quite similar in the two cases. The great similarity in the trends of ΔS* values for the acid and base hydrolysis reactions has been interpreted in terms of a rate-determining step that is primarily dissociative in both cases.
Studies on the solvent extraction of metal dithiocarbamates
Authors: Sastri Vedula S. , Aspila Keijo I. , Chakrabarti Chuni L.
Published: May 2006

Studies on the solvent extraction of morpholine dithiocarbamic acid complexes of divalent metal ions Mn, Fe, Co, Ni, Cu, Zn, Pb, Cd, Hg, and Sn were carried out, and the extraction constants and the overall stability constants were determined. The stability constants of complexes of Cu(II) formed with various substituted dithiocarbamic acids, showed a variation of the stability constants with the basicity of the nitrogen and sulfur atoms in the reagents.
Effects of hydrogen bonding and homoconjugation on the titration curves of a synthetic polynuclear phenolic compound in non-aqueous solvents
Authors: Chatterjee S. K.
Published: May 2006

A straight chain polynuclear phenolic compound containing 9 phenolic nuclei has been synthesized and titrated in several non-aqueous solvents. In some of the solvents, a stepwise neutralization of OH groups in the compound has been observed. Some of the OH groups in the compound have a hyperacid character, and a sharp increase in conductance was observed as these OH groups are neutralized by the base. Some of these features have been discussed in terms of intramolecular hydrogen bonding and homoconjugation between the acid and its anion.
Total synthesis of anisomycin
Authors: Wong C. M. , Buccini J. , Chang I. , Raa J. Te , Schwenk R.
Published: May 2006

Two synthetic approaches to anisomycin had been studied. One approach used 2R 3R tartaric acid as starting material and was successfully converted to the hydrochlorides of (+)-anisomycin (22) in an overall yield of about 5% and (−)-anisomycin (1) in about 1% yield. Liberation of the free bases gave (+)-anisomycin and (−)-anisomycin. The other approach started with α-anisyl pyrrole and was converted to (±)-deacetyl anisomycin 2. The conversion of 2 to anisomycin was done by treating natural deacetyl anisomycin with benzyl bromide to give 9. Conversion of 8 and 9 to (+)-anisomycin and (−)-anisomycin was done by selective acetylation with acetic anhydride and debenzylation under hydrogenation condition.
Photochemistry of nitroso compounds in solution. X. The reaction pattern of photo-excited nitrosamides
Authors: Chow Y. L. , Tam N. S. , Lee A. C. H.
Published: May 2006

The initial step in photolysis of alkyl N-nitrosamides 1 and 2 has been shown to be homolysis of the N—N bond, giving amidyl radicals and nitric oxide. Under the reaction conditions nitric oxide disproportionated, in part, to NO2 and NO3 radicals. The amidyl radicals abstracted hydrogen atoms inter-molecularly from the solvent as well as intramolecularly from the δ-carbon of the alkyl chain, but not from that of the acyl chain. The combined pathways lead to the observed products as shown in Schemes 1 and 2. By this photolysis, the functionalization at the unactivated δ-carbon site of the alkyl chain could be achieved in 55% yield.
Alkaloids of Lycopodiumalopecuroides. Part 3. Structure of alolycopine
Authors: Ayer W. A. , Altenkirk B.
Published: May 2006

The alkaloid alolycopine is shown to have structure 4a. The structural assignment is based on the interpretation of the infrared, ultraviolet, and nuclear magnetic resonance spectra of alolycopine and O-acetylalolycopine, and on a correlation of the latter with acetylanhydroaposerratinine (6).
Réactions de Ritter sur les tert-butyl-4 méthyl-1 cyclohexanols cis et trans
Authors: Richer Jean-Claude , Bisson Robert
Published: May 2006

not available
The mechanism of formation of pre-passive films on nickel: a chronoellipsometric study
Authors: Reddy A. K. N. , Rao B.
Published: May 2006

The authors have previously shown that the anodic passivation of nickel in acid solutions is a two-stage process; the first stage of which involves the formation of a pre-passive film. In this study, the mechanism of formation of the precursor film on nickel in a 0.5 M K2SO4 (pH = 3.1) solution has been investigated by means of the technique of chronoellipsometry which consists of the ellipsometric in situ monitoring of the anode surface during a galvanostatic experiment. The main finding is that, before the pre-passive film forms, there must elapse an induction time which is affected by the current density and mass-transport factors. The nature of the dependence of the induction time upon current density indicates that the pre-passive film is formed by a dissolution–precipitation mechanism. It is proposed that the pre-passive film consists of precipitated Ni(OH)2.
Calculation of reaction order for the homogeneous pyrolysis of organic vapors
Authors: Torok John , Sandler Samuel
Published: May 2006

A method is proposed for the derivation of a mathematical equation that relates the kinetic parameters of the propagation reactions of homogeneous free-radical chain reactions to the overall order of the reaction. The equation may be used in evaluating the predominant chain-termination reaction, provided that the mechanism of propagation of the chain is well understood. Application of the technique is demonstrated for the pyrolysis of n-butane. It predicts the predominance of the methyl–methyl radical recombination reaction.
Chemisorption of hydrogen on nickel–magnesia catalysts. Part I. General kinetic characteristics
Authors: Viswanathan N. S. , Yeddanapalli L. M.
Published: May 2006

A detailed study of the kinetics of hydrogen chemisorption on 3 different nickel catalysts, supported on magnesia and prepared by coprecipitation, has been made over a wide range of pressures and temperatures. The results have been analyzed in the light of the Elovich equation. Experimental data obtained by variations of pressure and temperature indicate the existence of a number of stages in the chemisorption process and support the multiple kinetic stage hypothesis suggested by Low. The effect of temperature on the parameters has been studied, and relations obtained which have been used to calculate activation energies for each of the stages.
A new direct synthesis of equilin from equilenin. Potassium–ammonia reduction of some non-conjugated double bonds
Authors: Marshall David J. , Deghenghi Romano
Published: May 2006

It is shown that the reduction of equilenin ethylene ketal with alkali metals in ammonia can be controlled to yield equilin ketal as the major product. With potassium at −33°, equilenin and equilin ketals are readily reduced to afford 8α-estrone ketals in good yield. Analogous reactions were observed with 2-naphthol.
Microwave spectrum of morpholine
Authors: Sloan J. J. , Kewley R.
Published: May 2006

The microwave spectra of morpholine and N-deuteromorpholine have been investigated within the 8 to 40 GHz region. For both the normal and the deuterated species, strong a-type spectra which are due to the chair conformer with an equatorial imino group were recorded. The ground vibrational state rotational constants and quadrupole coupling constants are (in MHz), for normal morpholine, A = 4924.88 ± 0.05, B = 4625.15 ± 0.05, C = 2684.25 ± 0.05, χaa = 2.22 ± 0.02, χbb = 2.51 ± 0.04, χcc = −4.73 ± 0.02, and for N-deuteromorpholine, A = 4925.39 ± 0.05, B = 4399.67 ± 0.05, C = 2607.09 ± 0.05, χaa = 1.92 ± 0.02, χbb = 2.59 ± 0.04, χcc = −4.51 ± 0.02. The rs coordinates of the imino hydrogen are (in Å) aH = 2.373 ± 0.005 and cH = 0.10 ± 0.03. For the normal species the dipole moment components are (in D) μa = 1.68 ± 0.01, μc = 0.30 ± 0.01, μ = 1.71 ± 0.02. The value of aH and the direction of μ with respect to the a and c principal axes confirm that the observed spectrum is that of the chair equatorial conformer of morpholine.
Structures of three minor alkaloids of Fumariaofficinalis L.
Authors: MacLean D. B. , Bell R. A. , Saunders J. K. , Chen C.-Y. , Manske R. H. F.
Published: May 2006

The structures of fumaricine, fumaritine, and fumariline, minor alkaloids of F. officinalis, have been deduced by spectroscopic methods and by comparison with model systems. Nuclear Overhauser effects observed in these systems aided in the solution of the structural problem. The three alkaloids have a common ring system and are structurally related to ochotensimine.
13C Nuclear magnetic resonance studies. XIII. 13C Carbonyl carbon shieldings of some β,γ-unsaturated ketones
Authors: Gurudata Gurudata , Stothers J. B.
Published: May 2006

The 15.1 MHz 13C nuclear magnetic resonance spectra of 13 aliphatic and alicyclic ketones having an olefinic bond in the β,γ position with respect to the carbonyl group have been recorded and the carbonyl shieldings measured. The major aim of this study was to investigate the possibility of detecting homo-conjugative interactions between the π-systems by comparing the carbonyl shieldings with those for the corresponding saturated and α,β-unsaturated systems. Some evidence of homoconjugation is presented on the basis of our previous interpretation of the factors governing carbonyl shieldings. A qualitative assessment of the observed geometrical dependence of the effect is offered.
Mass spectra and fragmentation mechanisms of some nitrophenylhydrazines and nitrophenylhydrazones
Authors: Benoit F. , Holmes J. L.
Published: May 2006

The mass spectra and fragmentation mechanism of 2- and 4-nitro and 2,4-dinitrophenylhydrazines and their N,N′ trideutero analogues are discussed with respect to the operation of an "ortho effect". The mass spectra of nitrophenylhydrazones of cyclohexanone, methyl cycolhexanones, and their deuterated analogues are discussed with reference to the fragmentation of the ketone portion of the molecule.
A nuclear magnetic resonance study of hydrogen bonding of δ-valerolactam
Authors: Purcell J. M. , Susi H. , Cavanaugh J. R.
Published: May 2006

The association of amide groups of δ-valerolactam through hydrogen bonding has been investigated by means of high resolution nuclear magnetic resonance spectroscopy in CCl4 and CDCl3 solutions. Chemical shifts of the NH proton signal were measured over a wide range of temperatures and concentrations. Thermodynamic properties associated with the [Formula: see text] hydrogen bond formation were evaluated from a least squares analysis by a direct search procedure with a digital computer. The obtained enthalpy values for hydrogen bond formation are in general agreement with results obtained by other methods.
Proton magnetic resonance spectrum of 2,6-dichlorobenzaldoxime. Signs and magnitudes of long-range spin–spin couplings. Degree of nonplanarity
Authors: Schaefer T. , Wasylishen R.
Published: May 2006

From the sign and magnitude of the coupling constant between the C—H proton in the sidechain and the para ring proton in 2,6-dichlorobenzaldoxime it is estimated that the deviation from coplanarity of the sidechain is at least 40°. The hydroxyl proton shift in dimethylsulfoxide solution of −11.7 p.p.m., relative to internal tetramethylsilane, indicates a cis arrangement of the hydroxyl and aromatic groups.
Reaction of hydrogen atoms with propane: relative Arrhenius parameters for the attack on the 1 and 2 positions
Authors: Campbell J. M. , Strausz O. P. , Gunning H. E.
Published: May 2006

Arrhenius parameters were measured for the relative rate of attack of hydrogen atom on the primary and secondary C—H bonds of propane. The mercury photosensitization of hydrogen was used as the source of hydrogen atom and the abstraction reactions were monitored by the formation of isomeric hexanes.Detailed kinetic analysis was applied to assess the importance of secondary reactions.
Kinetics of the anation reaction of nickel(II) and 1,10-phenanthroline in methanol–water mixtures
Authors: Sanduja M. L. , Smith W. MacF.
Published: May 2006

The kinetics of formation of the monophenanthroline complex of nickel(II) has been studied spectrophotometrically in water–methanol mixtures of 0 to 97 weight % of methanol, at ionic strength 0.050, at varying acidities at 25 °C. Values for the rate constants for the acid independent and acid dependent reactions together with values for the equilibrium acid ionization quotient of phenanthrolium ion over the range of solvent mixtures have been determined. The values of the acid independent rate constant show little dependence on solvent compositions up to 76% methanol, then decrease and show no correlation with trends in the ionization quotient of phenanthrolium ion. The acid dependent rate constant shows only a modest dependence on solvent composition over most of the range of solvent compositions except in the range of highest methanol content where it is not significantly different from zero.
Crystal structures of NaNiIO6, NaMnIO6, and KMnIO6
Authors: Brown I. D.
Published: May 2006

NaNiIO6 (a = 4.962, c = 5.148 Å, space group P312) is shown from X-ray powder patterns to be isostructural with trigonal KNiIO6. Approximate coordinates for the oxygen atoms are given. NaMnIO6 (a = 4.972, c = 5.136 Å) and KMnIO6 (a = 5.009, c = 6.000 Å) are probably also isostructural but the broadening of the X-ray powder lines in these compounds makes a complete analysis impossible. Powder patterns for all three compounds are given.
Polarography of thioketones
Authors: Elofson R. M. , Gadallah F. F. , Gadallah L. A.
Published: May 2006

Aliphatic and aromatic thiones are reduced at the dropping mercury electrode at potentials well below those of the corresponding ketones. The reductions take place by a mechanism whereby an electron is added to the molecule before protonation. The reducibility of camphorthione adds the isolated C=S group to the list of polarographically reducible functions. The half-wave potentials in acetonitrile correlate linearly with n → π* transitions in the electronic spectra.
Hydrogenolysis by LiAlH4–AlCl3 of an ether solution of norcamphor isobutylene ketal
Authors: Loewen P. C. , Zajac Jr. W. W. , Brown R. K.
Published: May 2006

An approximately 1:1 mixture of the two isomers (3 and 4) of norcamphor isobutylene ketal was hydrogenolyzed by AlH2Cl in ether at room temperature. The slow reaction (62% complete in 20 h; ∼96% complete in 168 h) produced only 1-(2-endo-norbornyloxy)-2-methyl-2-propanol (7), 2-(2-exo-norbornyloxy)-2-methyl-1-propanol (6), 2-exo-norborneol (10), and unchanged 3 and 4 in the proportion 64.5:26.5:4.5:4.5. Recovery of materials was at least 95%.Compound 10 is believed to arise from slow hydrogenolysis of the product 6. Since the unreacted ketal was still an approximately 1:1 mixture of the isomers 3 and 4, and because it is known that in the hydrogenolysis of acetals and ketals, the reduction by hydride donation is much faster than is the isomerization of the ketals, it is inferred that the two isomers (3 and 4) of norcamphor isobutylene ketal hydrogenolyze at approximately the same rate.Arguments are presented to support the view that isomer 4 reacts with two molecules of AlH2Cl, one as the Lewis acid and the other as the hydride donor, to provide product 7 and possibly some of product 6, while isomer 3 reacts with one molecule of AlH2Cl, which acts as the Lewis acid and the hydride donor, to provide most if not all of product 6 and some of product 7.
Kinetics of the acetone-photosensitized addition of HBr to ethylene
Authors: Wong K. T. , Armstrong D. A.
Published: May 2006

The kinetics of the acetone-sensitized photoaddition of HBr to ethylene are consistent with the free radical chain mechanism of Vaughan, Rust, and Evans. In the presence of excess propane the combination of bromine atoms (reaction [4]) is the main termination step, and bromoethyl radicals formed by the addition of bromine atoms to ethylene (reaction [2]) are collisionally stabilized. They undergo thermal decomposition (reaction [−2]) or abstract a hydrogen atom from hydrogen bromide (reaction [3a]) to form the product, ethyl bromide. The rate constant ratio, k−2/k3a, increases from 5.6 × 1018 molecules cm−3 at 15.3 °C to 11.5 × 1018 molecules cm−3 at 45.0 °C. This corresponds to E−2 − E3a = 4.5 ± 0.5 kcal mole−1, and is in accord with the thermochemical data. Within experimental error, k2 and k−2 are independent of propane pressure in the range 260 to 390 Torr. Also, [Formula: see text] is equal to 5.5 ± 0.3 × 108 cm3/2 molecule−1/2 s−1/2, independent of temperature over the range 15.3 to 45.0 °C, and E2 = 0.0 ± 0.5 kcal mole−1. In the absence of propane, and at ethylene pressures in excess of 400 Torr, the combination and disproportionation of bromoethyl radicals is the main termination process (reaction [7]). The value of [Formula: see text] is 8.9 ± 0.1 × 10−10 cm3/2 molecule−1/2 s−1/2 at 35.1 °C, in agreement with kinetic data for related reactions.
Some thermodynamic properties of the sulfolane–benzene and sulfolane–dichloromethane systems
Authors: Benoit R. L. , Charbonneau J.
Published: May 2006

Molar excess free energies of the systems sulfolane-benzene and sulfolane–dichloromethane have been calculated from static vapor pressure measurements at 30.00 °C. Refractive indices, excess partial molar volumes of mixing, and enthalpies of mixing at infinite dilution of benzene and dichloromethane were also determined.
2-Acetamido-2-deoxy-D-glycero-D-gulo-heptose
Authors: Williams D. T. , Perry M. B.
Published: May 2006

3,4,5,6,7-Pentaacetoxy-D-gluco-1-nitro-1-heptene with methanolic ammonia afforded crystalline 2-acetamido-1,2-dideoxy-1-nitro-D-glycero-D-gulo-heptitol which was converted via a modified Nef reaction to 2-acetamido-2-deoxy-D-glycero-D-gulo-heptose.
Lignans of western red cedar (Thujaplicata Donn). IX. Plicatinaphthalene
Authors: MacLean Harold , MacDonald B. F.
Published: May 2006

The last of nine lignans detectable by thin-layer chromatography in the hot-water soluble extractives of western red cedar (Thujaplicata Donn) heartwood has been determined as 6-hydroxy-2(hydroxy-methyl)-7-methoxy-4-(3′,4′-dihydroxy-5′-methoxyphenyl)-3-naphthoic acid lactone (plicatinaphthalene 2) by spectrometric methods, by degradation studies of derivatives, and by preparation of its trimethyl ether derivative 3 from dehydroanhydropicropodophyllin by opening of the methylenedioxy group with boron trichloride.
Chloryl compounds. Part II. Chloryl hexafluoroarsenate and chloryl fluoride
Authors: Carter H. A. , Johnson W. M. , Aubke F.
Published: May 2006

The infrared and Raman spectra of chloryl hexafluoroarsenate have been obtained. The observed vibrations have been interpreted in terms of an ionic compound ClO2+AsF6−, where strong cation–anion interaction results in a symmetry lowering of the AsF6− ion. The compound together with chloryl fluoride produces the chloronium cation ClO2+(solv) in solution of fluorosulfuric acid. The solvolysis of FClO2 is studied by conductometry and 19F nuclear magnetic resonance (n.m.r.) in order to elucidate the observed anion–cation interaction for ClO2AsF6 more fully. 19F n.m.r. studies of FClO2 and related molecules have been used to discuss the bonding in chloronium compounds.
Bromine chloride clathrate gas hydrate
Authors: Glew D. N. , Hames D. A.
Published: May 2006

Bromine chloride hydrate, prepared free of excess halogen, has been analyzed directly to give the formula BrCl•7.77 ± 1.58 H2O. The halogen is found to be bromine-rich in the hydrate and bromine-deficient in the aqueous solution at 5 °C. Aqueous solutions in equilibrium with the hydrate between 1 and 15 °C have been analyzed and yield the bromine chloride hydrate enthalpy of fusion 10 450 ± 860 cal/mole which leads to the formula BrCl•7.28 ± 0.60 H2O. It is concluded that bromine chloride forms a normal clathrate-type gas hydrate of formula BrCl•7.34 H2O, and that the frequently quoted formula BrCl•4 H2O is wrong.
Metal chelates of 2-(2′-thienyl)-8-hydroxyquinoline: anomalous ratios of formation constants
Authors: Corsini A. , Billo E. J.
Published: May 2006

The ligand 2-(2′-thienyl)-8-hydroxyquinoline has been synthesized and the solution stability of some of its metal chelates determined. The finding that log K1 < log K2 is attributed to strong steric interaction between the 2-substituent and coordinated water on addition of the first ligand. This interaction results in distortion toward tetrahedral geometry. Previously unexplained data for other 2-substituted 8-hydroxyquinolines have been interpreted in terms of this effect.
Hg(3P1) photosensitized decomposition of 2,5-dihydrofuran
Authors: Francis B. , Sherwood A. G.
Published: May 2006

The mercury photosensitized decomposition of 2,5-dihydrofuran was studied in the vapor phase at 25 ± 2 °C. Major products are carbon monoxide, propene, and hydrogen, while biallyl, allene, methylacetylene, furan, 2,3-dihydrofuran, tetrahydrofuran, and small amounts of three unidentified products are also produced. The quantum yields of all products are decreased by increasing substrate pressure, indicating collisional deactivation of an excited state precursor which, at low pressures, decomposes according to the scheme

[Formula: see text]The product P is not furan and its possible identity is discussed. The free radical component of the reaction was further studied by carrying out the reaction in the presence of nitric oxide. The results are consistent with the above processes.
Dérivés du tert-butyl-3 cyclohexène. II. Les tert-butyl-3 cyclohexanediols-1,2
Authors: Richer Jean-Claude , Freppel Christian
Published: May 2006

not available
Indoles and auxins. VII. Active esters and anhydrides of 3-indoleacetic acid
Authors: Hart Judith C. , Matheson Eileen M. , Hutzinger O.
Published: May 2006

The synthesis of activated esters and anhydrides of 3-indoleacetic acid is described. Their usefulness for the preparation of amino acid derivatives is shown by reaction with glycine methyl ester.
Studies of rhenium–carboxylate complexes. III. The crystal and molecular structure of tetra-μ-n-butyratodirhenium(III) diperrhenate
Authors: Calvo C. , Jayadevan N. C. , Lock C. J. L. , Restivo R.
Published: May 2006

One of the compounds obtained by the reaction of rhenium(III) chloride with n-butyric acid while exposed to oxygen has been shown by single crystal X-ray diffraction to be tetra-μ-n-butyratodi-rhenium(III) diperrhenate. The crystals are triclinic with lattice parameters a = 7.836(8) Å, b = 10.746(8) Å, c = 8.773(8) Å, α = 88.9(1)°, β = 106.5(1)°, and γ = 98.0(1)°. The space group is [Formula: see text] and there is one formula unit per cell. A total of 1593 independent reflections were examined and the structure was refined by full 3-dimensional least-squares to an R value of 0.123. Two rhenium environments are found, one consisting of a dimer unit bridged by 4 carboxylate groups and the other a per-rhenate group. This latter group, showing a mean Re—O distance of 1.75 Å, shares an oxygen atom with a rhenium atom in the dimer unit, and this Re—O bond length is 2.18 Å long. The structure results from packing of short chains, consisting of the dimer unit and the 2 perrhenate groups, running roughly parallel to the [111] direction.
N-Ammonium-S-thiosulfate zwitterions from alkaloids and tertiary amines
Authors: Edward John T. , Whiting Josephine
Published: May 2006

The compounds prepared by Tercinet (1) from the reaction of various alkaloids with silver sodium thiosulfate have been shown to have N-ammonium-S-thiosulfate structures; they are better prepared by reaction of the alkaloids with sodium tetrathionate.
Favorsky rearrangements of α-halogenated acetyl cycloalkanes. Part II
Authors: Engel CH. R. , Roy S. K. , Capitaine J. , Bilodeau J. , McPherson-Foucar C. , Lachance P.
Published: May 2006

On the basis of a study of the rearrangement with alkali of various α-halogenated 20-keto steroids in a variety of media, and in accord with data from the literature, a unifying explanation of the complex results obtained in Favorsky rearrangements of α-halogenated acetyl cycloalkanes is put forward.
Study of the Wallach rearrangement and related processes in the 100% sulfuric acid region
Authors: Buncel E. , Strachan W. M. J.
Published: May 2006

Study of the acid-catalyzed Wallach rearrangement of azoxybenzene is extended into the 100% H2SO4 region. The rate of formation of 4-hydroxyazobenzene can be followed spectrally in a straight-forward manner until close to 99% H2SO4, but in higher acidities sulfonation of this product becomes kinetically important. The advent of second equilibrium protonations of 4-hydroxyazobenzene and of 4-hydroxyazobenzene-4′-slfonic acid further complicate the azoxybenzene rearrangement as followed spectrally. Above 100% H2SO4 a second sulfonation is also observed. A method is given for dissecting the rate data for the primary rearrangement process from the first of the sulfonation reactions.The rate of the azoxybenzene rearrangement is observed to increase continuously up to 99.99% H2SO4 (the upper limit of the present kinetic method). This suggests that the second proton transfer step to azoxybenzene is rate-determining and not an equilibrium process. These results permit a clarification of a previously proposed mechanism (1).
Coordination complexes of gallium(III) and indium(III) halides. IV. Infrared spectra, Raman spectra, and structures of complexes with dimethylsulfoxide and dimethylsulfoxide-d6
Authors: Carty J. , Patel H. A. , Boorman P. M.
Published: May 2006

The preparation and characterization by far-infrared and Raman spectroscopy of dimethylsulfoxide (dmso) and dimethylsulfoxide-d6 (dmso-d6) complexes of gallium trihalides are reported. The compounds GaX3(dmso)6 (X = Br, I) have ionic structures containing the hexacoordinate cation Ga(dmso)63+. Reaction of gallium trichloride with dmso gives GaCl3(dmso)1.5. This compound appears to be identical with GaCl3(dmso)2 described by other workers and has been shown to have the structure [Ga(dmso)6][GaCl4]3. Some new vibrational data are presented for InX3(dmso)3 (X = Cl, Br) and InI3(dmso)2.