bluuebunny/crossref_metadata_2025 huggingface dataset:
Amino group stretching vibrations in primary aliphatic amines
Authors: Krueger P. J. , Smith D. W.
Published: May 2006

Primary aliphatic amines can be characterized by infrared spectroscopy as to the nature and degree of branching of the alkyl chain, using the fundamental antisymmetric and symmetric NH2 stretching frequencies measured in dilute C2Cl4 solution. Where steric and direct conjugation effects are absent both frequencies and the integrated intensity of the antisymmetric band increase linearly with decreasing inductive electron-donating power of the alkyl chain. The integrated intensity of the symmetric band, which is smaller than that for the antisymmetric band in all the 26 compounds studied, is independent of the inductive nature of the alkyl chain as a first approximation. These results indicate that the N-atom lone-pair orbital in RNH2 plays a negligibly small role in modifying the inductive effect of R on NH2 frequencies and intensities as long as the N-atom hybridization remains sp3.
Spin–spin interactions in polyphenyls
Authors: Gardner C. L.
Published: May 2006

An attempt has been made, with some success, to interpret the zero field splitting parameters for the triplet states of molecules such as the polyphenyls where the subunits are weakly coupled and the molecules are probably nonplanar. The method used was a semi-empirical exciton theory, applied in particular to biphenyl and 1,3,5-triphenylbenzene. In these two cases it is found that structure information, in particular the angle between rings, obtained by this method is in good agreement with electron diffraction data.
N-(2-Diazo-3-oxoalkanoyl)glycine esters. I. Synthesis of 4- and 5-phenoxyl derivatives and isomerization of N-(2-diazo-3-oxo-3-phenylpropanoyl)glycine ethyl ester
Authors: Looker James H. , Carpenter James W.
Published: May 2006

A new preparative procedure for N-(diazoacetyl)glycine ethyl ester is described. The interaction of N-(diazoacetyl)glycine ethyl ester with four phenoxyacetyl chlorides gives the 4-phenoxylderivatives of N-(2-diazo-3-oxobutanoyl)glycine ethyl ester, and with β-(o-methoxyphenoxy)-propionyl chloride yields N-[2-diazo-3-oxo-5-(o-methoxyphenoxy)pentanoyl]glycine ethyl ester. A general chromatographic procedure for separating N-(2-diazo-3-oxoalkanoyl)glycine ethyl esters from N-(chloroacetyl)glycine ethyl ester has been developed. Crotonyl chloride reacts with a 1 mole excess of N-(diazoacetyl)glycine ethyl ester to form N-(2-diazo-3-oxo-4-hexenoyl)glycine ethyl ester, and with a 2 mole excess to form N-{2-diazo-3-oxo-3-[4′-methyl-5′(carboethoxymethyl)carbamoyl-Δ2pyrazolin-3′-yl]propanoyl}glycine ethyl ester, presumably by isomerization of an initially formed Δ1-pyrazoline derivative. The interaction of benzoyl and m-bromobenzoyl bromide with N-(diazoacetyl)glycine ethyl ester results initially in yellow oily products which, on the basis of spectral data, are the expected N-(2-diazo-3-oxo-3-rylpropanoyl)glycine ethyl esters. During chromatographic purification and (or) attempted crystallization, there occurs an isomerization to colorless crystalline products. The analytical and molecular weight data, together with the spectral evidence, support the tentative assignment of 1,2,3-triazole structures to the isomerization products. A spontaneous reverse Dimroth rearrangement is postulated.
Reaction of glyoxal at the ortho position of phenols. Synthesis of 5a,10b-dihydrobenzofuro[2,3-b]benzofurans and 2-(3-benzofuranyl)phenols
Authors: Coxworth E. C. M.
Published: May 2006

The acid-catalyzed reaction of glyoxal at the ortho position of phenols has been shown to yield, as initial products, substituted 5a,10b-dihydrobenzofuro[2,3-b]benzofurans, such structures being indicated by the nuclear magnetic resonance spectra, and confirmed in several cases by synthesis via an unambiguous route. At higher temperatures in acidic media, and in the absence of glyoxal, these initial products were converted into the corresponding 2-(3-benzofuranyl)phenols. When glyoxal was present in acidic media, the 2-(3-benzofuranyl)phenols reacted further to give unidentified products of appreciably higher molecular weight.
Reaction of oxygen atoms with ethanol
Authors: Kato A. , Cvetanović R. J.
Published: May 2006

Reaction of O(3P) atoms with ethanol in the vapor phase has been studied at room temperature. The principal initial reaction products are water, acetaldehyde, and 2,3-butanediol. The data are consistent with abstraction of an α-hydrogen from ethanol as the primary step in the reaction. Ethanol is found to react with O(3P) atoms about 3.5 times less rapidly than acetaldehyde. The approximate absolute value of the rate constant of the ethanol reaction at 25 °C is 6.2 × 1010 cm3 mole−1 s−1.As a corollary to the investigation of the reaction of oxygen atoms with ethanol, a brief study has been made of the mercury Hg 6(3P1) photosensitized decomposition of ethanol at room temperature.
Isobaric yield distribution in the fission of uranium by medium-energy protons
Authors: Parikh S. S. , Marsden D. A. , Porile N. T. , Yaffe L.
Published: May 2006

The independent formation cross sections of 139Ba, 139Ce, 141Ce, and 143Ce, and the cumulative formation cross sections of 139Cs, 141Ba, and 143La, produced from the fission of natural uranium by protons of energies 20–85 MeV, have been measured radiochemically. The proton energies at which the excitation functions reach their maxima correlate well with the neutron-to-proton ratio of the fission product. Nuclear charge-dispersion curves exhibit, with increasing proton energy, the behavior previously found by other workers, i.e. broadening and a shift of the most probable nuclear charge towards stability.
Synthesis of mono- and di-functional benzyl and phenethyl derivatives containing silicon
Authors: Rotman Avner , Gertner David , Zilkha Albert
Published: May 2006

Dimethylbis(p-tolyl)silane was converted into the mono- or di-benzyl bromides by reaction with appropriate equivalents of N-bromosuccinimide; these were then converted into the nitriles, which were hydrolyzed to the corresponding phenylacetic acids or reduced to the phenethylamines. The mono- and di-phenethyl alcohols were prepared by reduction of the corresponding acids with lithium aluminium hydride. The dialdehyde, dimethylbis(p-formylphenyl)silane, was prepared by hydrolysis of dimethylbis(p-dibromomethylphenyl)silane.
Cyclobutadiene–metal complexes. XI. Tetramethylcyclobutadienecobalt(I) complexes
Authors: Bruce R. , Maitlis P. M.
Published: May 2006

The ligand-transfer reaction of tetramethylcyclobutadienenickel chloride dimer with dicobalt octacarbonyl gave tetramethylcyclobutadienedicobalt hexacarbonyl [Me4C4Co(CO)2Co(CO)4] and nickel tetracarbonyl. Triphenylphosphine replaced one carbonyl in Me4C4Co(CO)2·Co(CO)4 to give Me4C4Co(CO)2·Co(CO)3PPh3. Both Me4C4Co(CO)2·Co(CO)4 and Me4C4Co(CO)2·Co(CO)3PPh3 underwent cleavage with iodine at low temperatures to give tetramethylcyclobutadienecobalt dicarbonyl iodide (Me4C4Co(CO)2I); this was also obtained in quantitative yield from [Me4C4NiI2]2 and Co2(CO)8. One carbonyl in Me4C4Co(CO)2I was replaced on reaction with triphenylphosphine, giving Me4C4Co(CO)(PPh3)I. Me4C4Co(Co)2I reacted with both sodium cyclopentadienide and [C5H5Fe(CO)2]2 to give (π-cyclopentadienyl)-(π-tetramethylcyclobutadiene) cobalt.
The proton magnetic resonance spectrum of triptycene. The effect of magnetic anisotropy on the proton shifts
Authors: Kidd K. G. , Kotowycz G. , Schaefer T.
Published: May 2006

The ring proton spectrum of triptycene (2.2 mole % in CS2) was analyzed after the methine proton was decoupled. The modified ring current model accounts for most of the internal shift. Bond anisotropies and electron density contributions are also present. The latter account for the mean proton shift. The agreement between the predicted and calculated shifts is excellent for the proton meta to the methine substituent, but a discrepancy of 0.1 p.p.m. is found for the ortho proton. Correction for the ring anisotropy effects produces excellent agreement of the methine proton shift with the empirical correlation between the C—H proton shifts and the 13C–H coupling constants. The ring proton–proton coupling constants are little different from those in benzene, but a small strain in the bonds near the methine carbons is implied.
The effect of substituents on the Lewis acidity of α-cyanostilbenes
Authors: Stewart Ross , Kroeger D. J.
Published: May 2006

The effect of substituents in the two aromatic rings of α-cyanostilbene on the Lewis acidities of these compounds towards alkoxide ions has been examined. Substituents in the β ring produce effects on the acidity which correlate with the σ values of the substituents and yield an average ρ value of + 2.22. Substituents in the α ring, however, are correlated by the σ− values and yield an average ρ value of + 4.62. A p-nitro group in the α ring exhibits a greatly enhanced σ− value (+ 1.73).
Structural studies of mannans from Candida albicans (serotypes A and B), Candida parapsilosis, Candida stellatoidea, and Candida tropicalis
Authors: Yu R. J. , Bishop C. T. , Cooper F. P. , Hasenclever H. F. , Blank F.
Published: May 2006

Mannans have been isolated from cells of the following Candida species: C. albicans (serotype A), C. albicans (serotype B), C. parapsilosis, C. stellatoidea, and C. tropicalis. Methylation and hydrolysis of each mannan yielded the following methyl ethers of d-mannose (with only small variations in the relative amounts): 2,3,4,6-tetra-O-methyl-d-mannose, 3,4,6-tri-O-methyl-d-mannose (major), 2,3,4-tri-O-methyl-d-mannose (minor), 2,4,6-tri-O-methyl-d-mannose (minor), 3,4-di-O-methyl-d-mannose, and 3,5-di-O-methyl-d-mannose. The mannans therefore contained a predominance of 1 → 2 linkages in the linear portions, with smaller amounts of 1 → 6 and 1 → 3 linkages. Branching occurred through C-2 and C-6 of d-mannopyranose and d-mannofuranose units, and branches were terminated by d-mannopyranose units. The specific rotations of the mannans indicated that most of the glycosidic linkages were in the α configuration. The structural studies support the observation that the mannans are very similar serologically and show cross-reactivity in antisera to any of the parent organisms.
4-(Substituted)pteridines, analogues of kinetin
Authors: Lloyd Rodney F. , Skinner Charles G. , Shive William
Published: May 2006

Studies on the structural specificity of kinetin have demonstrated that a variety of 6-(substituted)aminopurines and 6-(substituted)thiopurines, even with an additional 2-fluoro or 2-amino substituent, replace kinetin in several biological systems. It was of considerable interest to investigate further the specificity of the imidazole ring by preparing a group of 4-(substituted)pteridines. That the pteridine ring cannot replace the purine ring with retention of activity is indicated by the inactivity of these compounds in stimulating the rate of lettuce seed germination either in the presence or in the absence of gibberellic acid.
The carbohydrates of the roots of the sugar maple
Authors: Scott Susan J. , Hay G. W.
Published: May 2006

Alkaline extraction of the chlorite holocellulose from the roots of the sugar maple (Acer saccharum) yielded a mixture of hemicellulose material which gave glucose, xylose, galactose, an acidic component, and arabinose in the approximate molar ratio of 14:22:1.7:1.9:1.0 upon acid hydrolysis. This crude hemicellulose was separated into four fractions by differential precipitation with Cetavlon. Methylation of two of these hemicelluloses resulted in further purification, and yielded two acidic glucoxylans (B-1-A and B-3-A) which were structurally distinct from the polysaccharides found in the shoot. Fraction B-l-A (degree of polymerization 144) consisted of a chain of β-(1 → 4)-linked d-xylose and d-glucose units, some of each of which were branched through C-3. The terminal, nonreducing units were d-xylose or sugar acid residues. Fraction B-3-A (degree of polymerization 96) also consisted of a chain of β-(l → 4)-linked d-xylose and d-glucose units, but branching occurred at C-3 of some of the d-xylose residues only. The carbohydrate composition of the mono- and oligo-saccharide fractions and of the other hemicelluloses was investigated.
Pyrrole chemistry. VII. Syntheses and reactions of some N-substituted pyrroles
Authors: Anderson Hugh J. , Griffiths S. John
Published: May 2006

In nitration, bromination, and formylation reactions 1-benzylpyrrole showed a greatly increased proportion of 3-substitution over both pyrrole and 1-methylpyrrole. The products of these reactions have been identified and interrelated. A number of attempts at hydrogenolysis under increasingly vigorous conditions failed to remove the benzyl group from methyl 1-benzyl-3-pyrrolecarboxylate. An attempt to use the 2,4-dinitrobenzenesulfenyl group to block the pyrrole nitrogen failed when the group entered the 2-position instead.
Temperature dependence of the shape of the cellodextrins in aqueous solution
Authors: Ihnat M. , Goring D. A. I.
Published: May 2006

Intrinsic viscosities of the cellodextrins, cellobiose to cellohexaose, were measured in aqueous solution at temperatures from 25 to 70 °C. Axial ratios were determined using the Einstein–Simha viscosity relation and the computational methods developed previously. The results showed that the oligomers are fully extended over this temperature range and that the negative temperature coefficients of the intrinsic viscosities are caused by the dehydration of the molecules with increasing temperature.
Polarographic reduction of some Schiff bases in dimethylformamide
Authors: Scott John M. W. , Jura W. H.
Published: May 2006

The half-wave potentials of a series of Schiff bases of the type

[Formula: see text], where Ar and Ar′ are unsubstituted aryl groups, have been measured in dimethylformamide. The effect of structural variations of the aryl groups Ar and Ar′ on these potentials have been calculated by the linear combination of molecular orbitals (l.c.m.o.) variant of the Hückel molecular orbital (H.m.o.) theory without specific consideration of the nitrogen heteroatom present in these compounds. It is demonstrated that the equation which relates E1/2 for the first electron transfer to theoretical quantities calculated by the l.c.m.o. theory can be applied to the data in several ways, one of which shows an interesting analogy with the Hammett σ−ρ treatment of linear free energy relationships.
Synthesis of some silicon-containing analogues of phenylalanine
Authors: Rotman Avner , Gertner David , Zilkha Albert
Published: May 2006

dl-Dimethylbis-p-(2-amino-2-carboxyethylphenyl)silane, which contains two molecules of phenylalanine connected by a dimethylsilyl bridge in the para position, and dl-p-(dimethyl-p-tolylsilyl) phenylalanine were prepared by using the malonic ester synthesis.
The effect of substituents on geminal proton–proton coupling constants
Authors: Fraser Robert R. , Hanbury Paul , Reyes-Zamora C.
Published: May 2006

A series of 2-benzyloxytetrahydropyrans bearing substituents at the ortho, meta, and para positions of the benzene ring have been synthesized. From the nuclear magnetic resonance spectrum of each compound, the geminal coupling constant (J) between the non-equivalent protons of the benzylic methylene group was determined. The geminal coupling constant for the methylene group of several benzyl sulfoxides was also measured. In the ether series it was found that J varied from 11.1 to 13.3 c.p.s. and was directly proportional to the Hammett σ value for the meta and para substituents. In the sulfoxides, however, J was unaffected by the substituent. On the basis of the molecular orbital theory of geminal coupling constants and steric considerations, it is proposed that the sensitivity of J to the substituent effect is dependent upon the conformation of the molecules with respect to the Ar—CH2 bond. The potential utility of this relation as a method of conformational analysis is discussed.
Selective benzoylation of benzyl β-l-arabinopyranoside and benzyl α-d-xylopyranoside
Authors: Sivakumaran T. , Jones J. K. N.
Published: May 2006

Benzoylation of benzyl β-l-arabinopyranoside with 2.2 molar equivalents of benzoyl chloride gave benzyl 2,3-di-O-benzoyl-β-l-arabinopyranoside (65–70%) and benzyl 2,3,4-tri-O-benzoyl-β-l-arabinopyranoside (10–15%). Benzyl α-d-xylopyranoside, under similar conditions, gave benzyl 2,4-di-O-benzoyl-α-d-xylopyranoside (45%), benzyl 2,3-di-O-benzoyl-α-d-xylopyranoside (27%), benzyl 2,3,4-tri-O-benzoyl-α-d-xylopyranoside (15%), and benzyl 2-O-benzoyl-α-d-xylopyranoside (9%). Several new derivatives of benzyl β-l-arabinopyranoside and benzyl α-d-xylopyranoside have been prepared. These benzoates lead to the ready preparation of 4-O-substituted l-arabinose and d-xylose derivatives. These results are compared with those obtained for the selective benzoylation of hexopyranosides.
Cyclic organophosphorus compounds. I. Synthesis and infrared spectral studies of cyclic hydrogen phosphites and thiophosphites
Authors: Zwierzak A.
Published: May 2006

A general synthetic procedure leading to cyclic hydrogen phosphites has been devised. The effect of solvent on the P==O and P—H infrared stretching modes of cyclic hydrogen phosphites and thiophosphites has been studied. It is concluded that association of cyclic hydrogen phosphites is attributable to dipole–dipole interactions rather than to hydrogen bonding.
Reductive cleavage of 2-alkoxy- and 2-aryloxy-tetrahydropyrans with LiAlH4–AlCl3
Authors: Diner U. E. , Brown R. K.
Published: May 2006

A series of 2-alkoxy- and 2-aryloxy-tetrahydropyrans has been hydrogenolyzed in ether by LiAlH4–AlCl3. As the alkyl group attached to the exo oxygen atom is changed from primary to tertiary, the proportion of ring cleavage to side-chain cleavage increases. Only side-chain cleavage occurs with the 2-aryloxytetrahydropyrans. The results are explained in terms of the polar properties of the alkyl or aryl group attached to the ring oxygen or the side-chain oxygen. Any control by steric factors is considered to be submerged by the polar effects, but does have a clearly apparent directive effect when the polar factors are equal for the two routes of cleavage. The results of the hydrogenolysis of 6-substituted 2-alkoxytetrahydropyrans could be explained on the same basis.The configurations of the cis and trans isomers of the disubstituted tetrahydropyrans were determined by nuclear magnetic resonance spectroscopy. Their conformational preference is discussed.
Derivatives of fluorene. XXV. Fluorofluorenes. VI
Authors: Namkung Moses J. , Fletcher T. Lloyd
Published: May 2006

The synthesis of 5,6,7,8-tetrafluoro-2-acetamidofluorene, 1,4,7-trifluoro-2-acetamidofluorene, and 5,8-difluoro-2-acetamidofluorene, of a 1,2,3,4,7-penta-, a 1,2,3,4-tetra-, a 1,2,4,7-tetra-, a 1,4,7-tri-, and a 1,4-di-fluorofluorenone, and of related derivatives is reported together with their infrared absorption data. Nitration of polyfluorofluorenones which have an unsubstituted 2 (or 7) position occurs at that position. An unexpected directive effect was observed in the nitration of 4,7-difluoro-2-acetamidofluorene.
Acyl azide photolysis. Proximity and ring-size factors and mechanism
Authors: Brown Ivor , Edwards O. E.
Published: May 2006

Photolysis of hexanoyl azide in cyclohexane gave 6-methyl-2-piperidone (13%), 5-ethyl-2-pyrrolidone (8%), and N-cyclohexylhexanamide (3%). In contrast, photosensitized decomposition of the azide with acetophenone gave hexanamide (78%), cyclohexene (11%), and dicyclohexyl (11%), but no lactams. It is concluded that the direct photolysis gives singlet acyl nitrene as the reactive species, which yields the δ-lactam preferentially. The importance of proximity in determining the γ- to δ-lactam ratio is emphasized.
Aminimides. II. A one-step synthesis of aminimides from carboxylic acid esters
Authors: McKillip William J. , Slagel Robert C.
Published: May 2006

The general applicability of preparing aminimides from esters and insitu generated 1,1,1-trimethylaminimine is reported. Acyclic, alicyclic, aromatic, and heteroaromatic trimethylaminimides have been synthesized by the one-step reaction. The synthetic scheme consists of reacting an ester with a 1,1,1-trimethylhydrazinium salt in the presence of an anhydrous base such as sodium methoxide. The choice of solvent, reaction temperature, and base and the electronegativity of the acyl substituent influence the ease of aminimide formation.
Photooxidation of methyl ethyl ketone vapor
Authors: Hoare D. E. , Whytock D. A.
Published: May 2006

The photochemical reaction between methyl ethyl ketone and oxygen has been studied at 150 °C with light of 3 130 Å. Measurement of the quantum yields of the major products of the reaction indicates the chain nature of the reaction, the length of the chain decreasing with increase in time. Extrapolation of quantum yields of products to zero time allows the evaluation of several relative rate constants and at least an indication of the individual radical sources of the observed products. It is shown that abstraction of hydrogen atoms from the methyl group takes place at least at a quarter the rate of abstraction of a secondary hydrogen from the ethyl group at 150 °C. In the initial products the ethyl group gives mainly acetaldehyde or perpropionic acid, the methyl group gives formaldehyde and methanol, and the carbonyl group gives carbon dioxide and perpropionic acid with a little carbon monoxide.
Mercury-photosensitized decomposition of dimethyl ether. Part II. The thermal decomposition of the methoxymethyl radical
Authors: Loucks Leon F. , Laidler Keith J.
Published: May 2006

The decomposition of the methoxymethyl radical, generated in the mercury-photosensitized decomposition of dimethyl ether, has been investigated over the temperature range 200 to 300 °C and the pressure range 3 to 600 mm Hg. The radical decomposes to give a formaldehyde molecule and a methyl radical. The effects of pressure and temperature on the first-order rate coefficient for the decomposition of the methoxymethyl radical have been examined in detail. The rate coefficient shows a pressure dependence over the full pressure range studied. The order of the decomposition is about 1.4 at the middle of the pressure range studied, with a lower order at higher pressures and a higher order at lower pressures. At 100 mm Hg the observed activation energy for the decomposition of the methoxymethyl radical is 24.8 kcal/mole.The first-order and second-order rate coefficients, k∞ and k0, corresponding to the limiting conditions of high pressures and low pressures respectively, have been evaluated as

[Formula: see text]Kassel integrations have been carried out for the methoxymethyl radical and have been fitted to the experimental data. It is concluded that 8 or 9 normal modes contribute to the energization of the radical. The rate coefficient is increased by the presence of carbon dioxide, but carbon dioxide has a lower efficiency than dimethyl ether for the transfer of energy in the energization process.
Réactions des époxydes avec la glycine et ses dérivés
Authors: Jankowski Krzysztof , Berse Casimir
Published: May 2006

not available
The infrared spectra of caffeine salts
Authors: Cook Denys , Regnier Zephyr R.
Published: May 2006

The infrared spectra of caffeine and its salts show that protonation occurs at position 9, the free nitrogen atom in the imidazole ring. N+H stretching and in-plane and out-of-plane bending modes have been assigned with the help of the deuterated salts. Protonation causes changes in some ring modes, accompanied by shifts in the carbonyl stretching frequencies to higher values.
The photodimerization of 3-(p-anisyl)-2-cyclohexenone and 3-(p-nitrophenyl)-2-cyclohexenone
Authors: Ege Seyhan N. , Yates Peter
Published: May 2006

Ultraviolet irradiation of 3-(p-anisyl)-2-cyclohexenone and 3-(p-nitrophenyl)-2-cyclohexenone has been found to give a single photodimer in each case, the structures of which have been established as the cis–anti–cis head-to-head cyclobutane derivatives XI and XIII, respectively.
Copper(II)-catalyzed oxidation of carbon monoxide by molecular oxygen
Authors: Byerley J. J. , Lee Jolland Y. H.
Published: May 2006

The kinetics of the copper (II)-catalyzed oxidation of carbon monoxide by molecular oxygen, i.e.

[Formula: see text] have been investigated in aqueous solutions at 120 °C. The rate law was found to be of the form −d[O2]/dt = kexpt[O2][CO][Cu(II)]/[H+], where kexpt = 7.88 × 10−6 M−1 s−1 in 0.25 M acetate solutions. The apparent activation energy is 29 600 cal/mole. The rate-determining step of the reaction appears to be the oxidation by molecular oxygen of a carbon monoxide insertion complex

[Formula: see text] formed in the pre-equilibrium step.
Kinetic order with respect to solvent: Acid hydrolysis and preferential solvation of the Reineckate ion
Authors: Langford Cooper H. , White John F.
Published: May 2006

The nuclear magnetic resonance technique of preferential solvation analysis developed by Frankel, Stengle, and Langford is applied to determination of the composition of the solvation shell about trans-[Cr(NH3)2(NCS)4]− in acetone–water mixtures. The composition of the solvation shell is correlated with the rate of acid hydrolysis of the chromium complex. It emerges that the solvolysis reaction is second order with respect to the solvolytically reactive solvent, water. The mechanistic implications of the rate law are considered as is the significance of analysis of preferential solvation for the determination of kinetic order of solvolytic reactions.
Sur quelques réactions acide–base dans les solvants fortement basiques anhydres. I. Éthylènediamine
Authors: Heumann W. R. , Bouchard A. , Tremblay G.
Published: May 2006

The neutralization of 20 monobasic acids of various strength in anhydrous ethylenediamine was studied potentiometrically using a platinum indicating electrode. The base used was the solvent anion's lithium salt LiHNC2H4NH2. Potential jumps ranging from 1 300 mV for hydrochloric acid to 150 mV for diphenylmethane were obtained. The latter compound was the least acidic (

[Formula: see text]) to react with the base. By plotting the half-neutralization potentials against the

[Formula: see text] values of the literature and extrapolating towards the potential obtained with the pure solvent, the

[Formula: see text] of ethylenediamine was estimated as 38. The potentials of the pure acid solutions varied little from one acid to another, which corroborates the opinion that even strong electrolytes are little dissociated in ethylenediamine. The potentials at half-neutralization, however, were much more different. These facts suggest that in this solvent acid strength is not as directly related to the degree of dissociation as in aqueous solutions. The neutralization of several dibasic acids was also attempted. Some were found to be too insoluble, the others gave unusual curves, which are difficult to explain.La neutralisation de 20 acides monobasiques de différentes forces dans l'éthylènediamine anhydre a été étudiée par potentiométrie avec une électrode indicatrice de platine. La base utilisée était le sel de lithium de l'anion du solvant LiHNC2H4NH2. Les sauts de potentiel variaient entre 1 300 mV pour l'acide chlorhydrique et 150 mV pour le diphénylméthane, qui était le composé le moins acide (

[Formula: see text]) à réagir avec la base. Si on porte les potentiels mesurés à la demi-neutralisation en fonction des

[Formula: see text] de la littérature et si on extrapole jusqu'au potentiel obtenu avec le solvant pur, on trouve une valeur de 38 pour le

[Formula: see text] de l'éthylènediamine. Les potentiels obtenus avec les solutions des différents acides purs variaient peu entre eux, ce qui confirme l'opinion que même les électrolytes forts sont peu dissociés dans l'éthylènediamine. Cependant, les potentiels à la demi-neutralisation variaient beaucoup plus d'un acide à l'autre. Ces faits semblent indiquer que dans ce solvant la force des acides ne varie pas aussi directement avec le degré de dissociation que dans les solutions aqueuses. La neutralisation de plusieurs acides polybasiques a été essayée également. Plusieurs de ces acides n'étaient pas assez solubles et les autres donnaient des courbes particulières, qui ne sont pas faciles à interpréter.
Low frequency infrared spectral studies on some of the molecular addition compounds of tin(IV) halides with triphenylphosphine and triphenylarsine
Authors: Rivest Roland , Singh Surjit , Abraham C.
Published: May 2006

Molecular addition compounds of tin tetrahalides with triphenylphosphine and triphenylarsine have been prepared. The analytical results show that triphenylphosphine forms both 1:2 (

[Formula: see text]) and 1:1 (

[Formula: see text]) adducts (L = ligand), whereas triphenylarsine forms only 1:2 adducts. The effect of addition of these ligands on the ν(Sn—X) (where X = Cl, Br) of the Lewis acids has been studied. In all cases, νd(Sn—X) have been found to shift to a lower frequency region on coordination. Tentative assignments for ν(Sn—Y) (where Y = P, As) have been discussed on the basis of the experimental results.Les complexes d'addition moléculaire de tetrahalogénures d'étain et la triphénylarsine et la triphénylphosphine ont été préparés. Les résultats analytiques indiquent que la triphénylphosphine forme deux sortes de complexes

[Formula: see text] et

[Formula: see text] (L est le ligand), tandis que la triphénylarsine ne forme qu'une sorte de complexes

[Formula: see text]. L'effet de l'addition de ces ligands sur la fréquence ν(Sn—X) (où X = Cl ou Br) des acides de Lewis a été étudié. Dans chaque cas, νd(Sn—X) diminue à cause de la coordination. On discute aussi de l'attribution possible de certaines bandes à ν(Sn—Y) (où Y = P ou As).
Studies on metal hydroxy compounds. IV. Infrared spectra of cadmium derivatives Cd(OH)2, CdOHCl, and CdOHF
Authors: Srivastava O. K. , Secco E. A.
Published: May 2006

Infrared spectra of hexagonal Cd(OH)2, CdOHCl, and CdOHF, along with deuterated analogues CdODCl and CdODF, in the range 2.5–16 μ are reported for the first time. The effects of substituting a halogen for an OH group in Cd(OH)2 are (i) shift of OH stretching vibration to a lower frequency and (ii) appearance of strong absorption bands in the region 8–16 μ. All the observed bands in the deuterated analogues are displaced to lower frequencies with νH/νd ratios between 1.35–1.37. The spectra of CdOHCl and CdOHF show a high correlation with their zinc analogues and although both spectra appear consistent with a simple molecule of Cs or C1 symmetry, an alternate interpretation is given in terms of OH lattice vibrations.
Reaction mechanism studies. 4. The diaxial → diequatorial rearrangement of β-chlorothioethers
Authors: King J. F. , Abikar K. , Deaken Donna M. , Pews R. G.
Published: May 2006

Benzenesulfenyl chloride adds diaxially to 5α-cholest-2-ene (1) yielding 2β-chloro-3α-(phenylthio)-5α-cholestane (3). Assuming that the reaction proceeds via the episulfonium ion (2), this allows the inclusion of these species within the scope of the diaxial opening rule. On heating, 3 undergoes rearrangement to 3β-chloro-2α-(phenylthio)-5α-cholestane (4). This reaction is the first instance of a diaxial → diequatorial rearrangement of β-halothioethers.Mild oxidation of 3 gives a mixture of the two sulfoxides epimeric at the sulfur atom (16a and 16b). On heating, both sulfoxides suffer pyrolytic elimination, without any sign of diaxial → diequatorial rearrangement. A major product of the elimination, evidently 2-chloro-5α-cholest-2-ene (18), was found to be formed a little more readily from the S-sulfoxide (16b) than from the R-isomer (16a). This observation is in accord with the conclusion of previous investigators that the elimination of the sulfenic acid from an alkyl sulfoxide involves bond formation between the hydrogen and sulfinyl oxygen during the rate determining stage (cf. 19).
Low molecular weight carbohydrates from potato(Solanium tuberosum)
Authors: Urbas Branko
Published: May 2006

An investigation was made of the low molecular weight carbohydrates of potato, Netted Gem variety. The material soluble in 80% alcohol was fractionated and separated by a combination of charcoal–Celite column and paper chromatography. Fifteen major components were isolated and characterized, and five minor components were detected. The major components were galactose, glucose, fructose, myoinositol, and eleven oligosaccharides, namely, sucrose, melibiose (Galp 1 → 6 Gp), maltotriose (Gp 1 → 4 Gp 1 → 4 Gp), digalactosyl glycerol (Galp 1 → 6 Galp, 1 → 1 Glyc), glucosyl → myoinositol, raffinose (Galp, 1 → 6 Gp 1 → 2 Fruf), planteose (Galp, 1 → 6 Fruf 2 → 1 Gp), galactinol (D-1-O-α-D-galactopyranosyl-myoinositol), manninotriose (Galp 1 → 6 Galp, 1 → 6 Gp), stachyose (Galp 1 → 6 Galp 1 → 6 Gp, 1 → 2 Fruf), and trigalactosyl glycerol (Galp 1 → 6 Galp 1 → 6 Galp 1 → 1 Glyc). The five components detected in small amounts were: three disaccharides, ribosyl-glucose, xylosyl-glucose, and arabinosyl-glucose, and two trisaccharides both made up of fructose and glucose units in the ratio of 2:1.
Convenient synthesis of myristicinaldehyde
Authors: Shulgin Alexander T.
Published: May 2006

The conversion of isomyristicin to a Schiff base of myristicinaldehyde is described. The subsequent hydrolysis of this base to the free aldehyde establishes a convenient preparation of this material. Apiolealdehyde is similarly generated from isoapiole, suggesting that this procedure may have general application in the conversion of the natural aromatic ethers of essential oils to the correspondingly substituted benzaldehydes.
γ-Radiolysis of cyclohexane with electron scavengers. II. Solid cyclohexane at 77 °K
Authors: Sagert N. H.
Published: May 2006

The γ-radiolysis of homogeneous solid solutions of SF6 and N2O in cyclohexane has been examined at 77 °K. With SF6, yields of the major products, hydrogen, bicyclohexyl, and cyclohexene, were all reduced, and no large yields of other products were observed. Thus, since SF6 reduces hydrogen yields by capturing electrons, combination of the SF6 anion and cyclohexane cation does not lead to bond breaking. Experimental evidence suggests that the ratio of disproportionation to combination of cyclohexyl radicals in solid cyclohexane at ~ 186 °K is 0.3 ± 0.2.With N2O, hydrogen yields are decreased to 3.5 G units, but large yields of cyclohexene, bicyclohexyl, and cyclohexanol (4.7, 2.0, and 1.0 G units respectively) are produced. Thus combination of O− and the cyclohexane cation leads to a great deal of bond breaking. The yields are explained by a mechanism similar to Dyne's mechanism for the radiolysis of hydrocarbons. It was, however, necessary to assume that excited states of cyclohexane formed directly behave differently from those formed by electron–cation combination.
New polyatomic cations of the group VI B elements: I. Solutions of selenium in highly acidic solvents
Authors: Barr J. , Gillespie R. J. , Kapoor R. , Malhotra K. C.
Published: May 2006

Colored solutions of selenium in fluorosulfuric, sulfuric, and disulfuric acids have been investigated by conductometric, cryoscopic, spectrophotometric, and magnetic methods. Evidence is presented for the new species Se42+ and Se82+ in the yellow and green solutions respectively.
Reactions of oxygen atoms with 2-propanol and methanol
Authors: Kato A. , Cvetanović R J
Published: May 2006

An investigation of the reaction of 2-propanol at 25 °C with oxygen atoms in the ground electronic state, O(3P), and, as a corollary, with the excited mercury atoms, Hg 6(3P1), has been carried out. The reaction of oxygen atoms with methanol at 25 °C has also been briefly studied. The general mechanism of reaction of O(3P) atoms with simple alcohols is discussed.
Note on the thermodynamic state of laminar flow and on the viscosity of liquids
Authors: Flood E. A. , Bartholomew R. F.
Published: May 2006

Fluids in a steady state of laminar flow (shear) are not in their thermodynamic equilibrium states. They have more energy and (or) less entropy than their corresponding static states.Phenomenological considerations suggest that in the case of 'ideal' liquids, shear states involve dilational energy increases, while in the case of ideal gases shear states involve entropy decreases associated with distortions of momentum fluxes.It is shown that the viscosities of some liquids (metals, hydrocarbons, water, etc.) can be described approximately by the equation[Formula: see text]where η is the viscosity, β the compressibility, D the coefficient of self-diffusion, M the molecular weight, ρ the density, and Nv Avogadro's number. F measures the strain or effective dilation necessary for a 'layer' to flow over an adjacent 'layer'. Ideally F should be about 0.06 but varies from about 0.05 for metals to 0.14 for water.Equation [a] implies that liquids in a state of laminar flow are somewhat dilated compared with the static state at the same temperature and pressure. The density change as a function of the velocity gradient u′ is given by[Formula: see text]
Infrared spectra and thermal decompositions of metal acetates and dicarboxylates
Authors: Patil K. C. , Chandrashekhar G. V. , George M. V. , Rao C. N. R.
Published: May 2006

The infrared spectra of rare earth acetates have been studied to examine the metal-acetate bonding. The thermal decomposition of rare earth acetates as well as lead and copper acetates have been investigated in detail by employing thermogravimetric analysis and differential thermal analysis. Thermal decomposition of calcium dicarboxylates (malonate to sebacate) have been studied employing t.g.a. and d.t.a. Infrared spectra of the dicarboxylates have also been studied. Preliminary results on the products of decomposition of dicarboxylates have been reported.
Trifluoromethylfluoroformate
Authors: Johnston Timothy , Heicklen Julian , Stuckey Wayne
Published: May 2006

Trifluoromethylfluoroformate (CF3OCFO) was produced as a secondary product in the mercury-photosensitized oxidation of 2-C4F8. It was identified by its mass, infrared, and fluorine n.m.r. spectra, as well as by vapor density and physical property determinations.
Mixed ligand complexes of cadmium(II)
Authors: Paul B. , Rao D. V. Ramana
Published: May 2006

Trichloro or tetrachloro cadmium(II) compounds were reacted with thiourea in ethanolic medium and mixed ligand anionic complexes having the formula M+(CdCl3•tu)−, where M is tetraethyl ammonium, tetraphenyl arsonium, and tetraphenyl phosphonium, have been characterized. The infrared spectra indicate the presence of both the quaternary halide and thiourea.
Mass spectral studies of some desaurins and related 3,5-bismethylene-1,2,4-trithiolanes
Authors: Yates Peter , Lynch Thomas R. , Weiler L. S.
Published: May 2006

The mass spectra of three desaurins and four related 3,5-bismethylene-1,2,4-trithiolanes have been interpreted with the aid of metastable peak assignments and accurate mass measurements. Strong molecular ion peaks are observed in the case of the aryl desaurins but not in that of their trithiolane counterparts. A variety of fragmentation pathways are postulated for the molecular ions, including cleavage on either side of a carbonyl group and elimination of a molecule of acylthioketene. In the case of the desaurins the latter process results in the formation of acylthioketene molecular ions, which could be distinguished from the doubly charged desaurin molecular ions. In the case of two of the trithiolanes, it is proposed that the ions resulting from loss of acylthioketene from the molecular ions undergo a novel type of McLafferty rearrangement and loss of carbon suboxysulfide to give aryl mercaptan molecular ions.
Reagent effects on distribution of methylsulfonylethyl substituents in the D-glucopyranosyl unit of cotton cellulose
Authors: Rowland Stanley P. , Bullock Austin L. , Cirino Vidabelle O. , Wade Clinton P.
Published: May 2006

The distribution of methylsulfonylethyl substituents at the 2-O-, 3-O-, and 6-O-positions of the monosubstituted D-glucopyranosyl unit of cotton cellulose was found to be a function of the specific reagent and the reaction conditions. The distribution is dependent upon the extent to which rate or equilibrium of reaction at the individual hydroxyl groups is the controlling factor. Under conditions which approach equilibrium in the reaction of methyl vinyl sulfone with cotton cellulose, the ratio of 2-O- to 6-O-substitution is 0.14:1.0. A variety of precursors for methyl vinyl sulfone (i.e., 2-(methylsulfonyl)-ethanol, [2-(rnethylsulfonyl)ethyl]pyridinium chloride, 2-bromoethyl methyl sulfone, and to-[2-(methylsulfonyl)ethyl]ether) react with cotton cellulose under non-equilibrium conditions to generate ratios of 2-O- to 6-O-substitutions as high as 0.44:1.0. The effect of diffusion of reagents into the cotton fiber upon the distribution of substituents is clearly evident in these reactions. Specific modifications of the process of reaction of methyl vinyl sulfone or 2-(methylsulfonyl)ethanol with cotton cellulose yield ratios of substituents in the 2-O- to 6-O-positions as high as 0.8:1.0; this ratio is similar to those which characterize certain rate-controlled Williamson etherification reactions with cotton cellulose.
Chemistry of phosphorus fluorides. Part III. The reaction of thiophosphoryl-fluoride with dimethylamine and some properties of the dimethylaminothio- phosphoryl fluorides
Authors: Cavell R. G.
Published: May 2006

Dimethylamine reacts with thiophosphoryl fluoride with non-integral stoichiometry to yield the volatile compound dimethylaminothiophosphoryldifluoride and the solid products contained hexafluoro-phosphate and difluorodithiophosphate ions, and an unstable complex ion containing phosphorus and fluorine. The reaction of dimethylaminothiophosphoryldifluoride with dimethylamine to form bis-(dimethylamino)thiophosphorylfluoride has also been studied. The solid residues of this reaction contained hexafluorophosphate and difluorodithiophosphate ions and an unidentified phosphorus-fluoride salt. Dimethylaminothiophosphoryldifluoride did not complex with boron trifluoride but reacted with hydrogen halides to yield the halogenothiophosphoryldifluorides. Physical and spectroscopic data on the alkylaminothiophosphoryl fluorides are reported.
Reactivity of metal–metal bonds. IV. The reaction of sulfur dioxide with compounds containing Sn—Sn and Sn—Mn bonds
Authors: Carey N. A. D. , Clark H. C.
Published: May 2006

The reactions of sulfur dioxide with the compounds R6Sn2 and R3SnMn(CO)5 (R = CH3 or C6H5) have been studied. In all cases the evidence indicates that the metal–metal bond has been cleaved. With the ditins the new compounds R3Sn•SO2 (R = CH3 or C6H5) and R3Sn•2SO2 (R = C6H5) were obtained, while the mixed bimetallic compounds gave R3SnMn(CO)5•2.5SO2 (R = CH3 or C6H5) and R3SnMn(CO)5•1.5SO2 (R = CH3). The possible structures of these derivatives are discussed.
The synthesis and identification of allyl ethers of glucose and cellulose
Authors: Hoiness D. E. , Wade C. P. , Rowland S. P.
Published: May 2006

Substituent group distribution in allyl cellulose, resulting from the base-catalyzed condensation of sodium allyl sulfate with cotton cellulose and having a degree of substitution of 0.07, was found to be 0.7:0.2:1.0 in the 2-O-, 3-O-, and 6-O-positions of the anhydroglucose units. Several new glucose derivatives were prepared in the syntheses of the 2-O-, 3-O-, and 6-O-allyl-D-glucoses.
Phosphinohydrazines. Reactions of hydrazine and alkylhydrazines with substituted phosphines
Authors: Peterson L. K. , Wilson G. L.
Published: May 2006

Reactions between hydrazine or N,N-dimethylhydrazine and (CF3)2PI, (CF3)2PCl, (CF3)3P, and (CF3)2PNMe2 have been further investigated as synthetic routes to phosphinohydrazine compounds. The new compound N,N-dimethyl,N′-bis(trifluoromethyl)phosphinohydrazine (m.p. 40.45°, b.p. 112° extrapolated) is described, and instability of [(CF3)2P]xN2H4−x systems with respect to elimination of fluoroform is inferred.
Thiazoloisoquinolines. III. Structure and methylation of 2-hydroxythiazolo[4,5-c]- and -[5,4-c]isoquinolines
Authors: Hall Catherine E. , Taurins Alfred
Published: May 2006

2-Hydroxythiazolo[4,5-c]isoquinoline (1) and 2-hydroxythiazolo[5,4-c]isoquinoline (2) were both found to exist predominantly in the lactam form (1b and 2b respectively) from infrared, nuclear magnetic resonance, and ultraviolet spectral evidence. Various methylating agents methylated compound 1 exclusively on the N-3 atom in the thiazole ring. Compound 2 on the other hand, gave a mixture of O-and N-3 methylated products with diazomethane and a mixture of N-1 and N-4 methylated products with either methyl iodide or dimethyl sulfate.
Pyrone studies. Linear α-pyrone route to protected β-polyketones
Authors: Douglas J. L. , Money T.
Published: May 2006

Preliminary studies on an alternative polypyrone route to protected β-polyketo acid chains are reported. The synthesis of the basic pyrone units involved and their conversion to C-3 acylated compounds are described.
Rates of reaction of n-butanethiol with some conjugated heteroenoid compounds
Authors: Lough C. E. , Currie D. J. , Holmes H. L.
Published: May 2006

The reactions of substituted 3-benzal-2,4-pentanediones, ethyl benzalacetoacetates, diethyl benzalmalonates, benzalmalonamides, cinnamalmalononitriles, β-nitrostyrenes, and β-nitropropenylbenzenes with excess n-butanethiol go essentially to completion in 20% aqueous ethanolic solution buffered to pH 7. The second order rate constants derived from the reactions of meta- and para- substituted derivatives correlate well with Hammett a constants. The nature and conformation of the functional group cis to the phenyl group determines the extent to which ortho substituents hinder the reaction.
Carcinogenicity of lactones. II. x-Ray crystal structure analyses of ± 3-benzylamino-4-hydroxypentanoic acid lactone hydrochloride and hydrobromide
Authors: Jones J. Bryan , Koo Chung Hoe , Mellor Ian P. , Nyburg S. C. , Young John M.
Published: May 2006

X-Ray crystal structure analysis of the hydrochloride of ± 3-benzylamino-4-hydroxypentanoic acid lactone shows the methyl and benzylamino groups to be trans-oriented.The hydrobromide is not isomorphous with the hydrochloride and its crystals are optically active owing to spontaneous resolution during crystallization. Refinement of both crystal structures is in progress.
Catalytic decomposition of acetonedicarboxylic acid
Authors: Larson D. W. , Lister M. W.
Published: May 2006

The decomposition of acetonedicarboxylic acid at various pH and in the presence of cobalt, nickel, copper, and zinc perchlorates as catalysts has been investigated. In addition the equilibrium constants for the formation of complexes between the metal ions and the acetonedicarboxylate ion have been measured.The copper complex appears to differ from the others in being more acidic, and also in its infrared spectrum. The kinetic results have been interpreted in terms of rate constants for the decomposition of each of the complexes, and a qualitative (but not a quantitative) correlation seems to exist between the rate constants and the stability constants of the complexes.