bluuebunny/crossref_metadata_2025 huggingface dataset:
CHARACTERISTIC VIBRATIONAL FREQUENCIES OF OXYGEN COMPOUNDS OF SILICON, PHOSPHORUS, AND CHLORINE: CORRELATION OF STRETCHING FREQUENCIES AND FORCE CONSTANTS WITH BOND LENGTHS AND BOND ORDERS
Authors: Robinson E. A.
Published: May 2006

For oxygen compounds of chlorine, phosphorus, and silicon, respectively, correlations are established between stretching frequencies and force constants of Cl—O, P—O, and Si—O bonds, and their bond lengths.By deducing bond orders on the assumption that only [Formula: see text]and [Formula: see text] orbitals on the central chlorine, phosphorus, or silicon atom are utilized in the formation of double bonds with lone pairs of electrons on oxygen, linear correlations between bond orders and force constants are established.The present treatment leads to the conclusion that the presence of a maximum of 12 electrons in the valency shells of chlorine, phosphorus, and silicon is required to best explain the bond length and force constant data, when highly electronegative ligands such as oxygen or fluorine are attached to the central silicon, phosphorus, or chlorine atom.
SOLVENT EFFECTS ON THE PROTON RESONANCE SPECTRA OF THE DICHLORO- AND DIBROMO-ETHYLENES: REACTION FIELD EFFECTS IN ALIPHATIC SOLVENTS AND SPECIFIC INTERACTIONS IN AROMATIC SOLVENTS
Authors: Hruska F. , Bock E. , Schaefer T.
Published: May 2006

The proton resonance shifts relative to internal cyclohexane and tetramethylsilane of cis and trans dichloro- and dibromo-ethylenes were measured in dioxane–water solutions, aliphatic solvents, and aromatic solvents. The dielectric constants of the dioxane–water solutions could be smoothly varied between 2 and 10 and, by taking Δ = cis–trans shifts as containing only the dipolar reaction field effect, the data for these solutions were treated as a test of the Buckingham reaction field equation. Linear plots were obtained and reasonable values of the coefficients of the E term confirmed the usefulness of this equation. An equation based on a nonspherical cavity was also used. It was also shown that quadrupolar reaction fields affected the proton shifts. Sizeable deviations from the dioxane–water standards were found for halogenated aliphatic solvents and those containing double or triple bonds. These deviations are interpreted in terms of the shape of the solute molecules and dispersion and anisotropic interactions. The much larger deviations found for aromatic solvents are harder to rationalize but specific interactions were found for both cis and trans forms, indicating an inadequacy in a simple dipole-induced dipole model.
A NEW TYPE OF CARBOHYDRATE ORTHOESTER: SIDE REACTIONS OF THE KÖNIGS-KNORR SYNTHESIS
Authors: Giam C. S. , Goldschmid H. R. , Perlin A. S.
Published: May 2006

A trisaccharide orthoester (IV) is one of the products formed by decomposition of 2,3,4,6-tetra-O-acetyl α-D-mannopyranosyl bromide in the presence of silver oxide. This new type of carbohydrate derivative contains three units of D-mannose linked together through the functional groups of a molecule of acetoacetic acid. The carboxyl group of the latter takes part in the orthoester structure of IV, with one D-mannose unit closing a 1,2-orthoester ring, and another unit comprising the —OR group through its anomeric center; the keto group of the acetoacetate forms a 1,2-ketal structure with the third D-mannose unit. The n.m.r. spectra characteristics of the trisaccharide and some related compounds are described. The following sequence of reactions is consistent with formation of the trisaccharide: 1,2-trans-acetoxyl bromide [Formula: see text] 1,2-cyclic acetoxonium ion (IX)[Formula: see text] 1,2-cyclic ketene-acetal; ion IX and 2,3,4,6-tetra-O-acetyl D-mannose then added to the ketene derivative.Selective degradation of trisaccharide IV yields a novel type of ketal, i.e., 1,2,O-[1-(carbomethoxymethyl)-ethylidene]-β-D-mannose.
ELECTROPHILIC DISPLACEMENT REACTIONS: XV. KINETICS AND MECHANISM OF THE BASE-CATALYZED PROTODEBORONATION OF ARENEBORONIC ACIDS
Authors: Kuivila Henry G. , Reuwer Jr. Joseph F. , Mangravite John A.
Published: May 2006

An investigation of the kinetics of the protodeboronation of benzeneboronic acid in water in the pH range 2.0 to 6.7 is described. In addition to the acid-catalyzed reaction studied earlier a reaction whose rate is independent of pH and one whose rate increases linearly with hydroxide ion concentration have been observed. The effect of malonate buffer concentration at low pH confirms the earlier observations of general acid catalysis. Changes in buffer concentration at pH 6.70 have no effect on rate indicating specific hydroxide ion catalysis. Effect of substituents in the ortho, meta, and para position of the benzene ring on the rate of protodeboronation have been examined. Ortho–para ratios for this reaction are high; possible reasons for this are discussed. The Hammett equation using σ correlates the rates for meta and para substituents.
PHASE TRANSITIONS OF WATER AND XENON ADSORBED IN POROUS VYCOR GLASS
Authors: Litvan G. , McIntosh R.
Published: May 2006

Measurements of the expansion of porous Vycor glass containing fixed quantities of adsorbed water indicate that in every instance a phase transition starts below −50 °C, with the main change occurring below −160 °C. Two other anomalies of the length variation were observed near −22 °C and −7 °C when the amount of adsorbed water exceeded the value equivalent to two monolayers. The length of the adsorbent after completion of a temperature cycle was different from the initial length. This is thought to be due to damage suffered by the glass and to the fact that the length of the adsorbent is different for adsorption and desorption although the quantity adsorbed may be the same.The phase transition of adsorbed xenon takes place below the normal triple point and is a function of surface concentration as shown by length variations and equilibrium pressures for fixed quantities adsorbed. All transitions are gradual and hysteresis is exhibited by the isosteres. The adsorption isotherms for xenon – Vycor glass show a decreasing adsorptive capacity and a contraction of the hysteresis loop with lower temperature. The inadequacy of the capillary condensation theory of adsorption in relation to these results is discussed.
THE EFFECT OF ALKYL GROUP VARIATION ON THE RATES OF SOLVOLYSIS OF ALKYL SULPHONIUM HALIDES
Authors: Hyne J. B. , Golinkin H. S.
Published: May 2006

not available
CONDENSATION OF ALICYCLIC KETONES WITH UREA AND THIOUREA
Authors: McKay A. F. , Podesva C. , Tarlton E. J. , Billy J.-M.
Published: May 2006

The previous assignment of a cis conformation to cyclohexyl 2-carbamylcyclohexylamine, which was prepared by the condensation of urea with cyclohexanone, has been confirmed by equilibration in the presence of potassium t-butoxide. The failure of 4-t-butylcyclohexyl 2-carbamyl-4-t-butylcyclohexylamine to equilibrate under the same conditions is discussed in relation to its structure. 1,2,3,4,5,6,7,8-Octahydroacridine was prepared by the condensation of 2,2′-methylene-bis-cyclohexanone with urea.
ON THIOSEMICARBAZONE–COPPER (I) COMPLEXES. PART IV
Authors: Gingras B. A. , Sirianni A. F.
Published: May 2006

The structure of thiosemicarbazone–copper (I) complexes has been studied further and new data have been obtained. The most probable structure has the metal linearly coordinated to a sulphur atom of a thiosemicarbazone molecule and a nitrogen atom of a second molecule. The diamagnetism of the complexes can be accounted for by a copper–copper interaction. Molecular weights of two typical complexes have been measured by a vapor pressure lowering method in benzene. The complexes were found to associate in this solvent but appeared as dimers at infinite dilution.
SYNTHESIS OF METHYL 4-ACETAMIDO-4-DEOXY-L-ERYTHROFURANOSIDE: A SUGAR WITH NITROGEN IN A FIVE-MEMBERED RING
Authors: Szarek W. A. , Jones J. K. N.
Published: May 2006

The synthesis of methyl 4-acetamido-4-deoxy-L-erythrofuranoside from D-ribose is described. The structural features that are believed to be necessary for the replacement of the ring oxygen of sugars by nitrogen are discussed.
1,1′-SPIROBIINDANES
Authors: Barclay L. R. C. , Chapman Ralph A.
Published: May 2006

The product from both the acid-catalyzed cyclodehydration of 4-methyl-4-phenyl-2-pentanone (1a) described by Hoffman (1) and by Barnes and co-worker (2) and the reaction of the saturated cyclic dimer of α-methylstyrene with aluminum chloride reported by Adams and co-workers (3) was shown to be 3,3,3′,3′-tetramethyl-1,1′-spirobiindane (IXa) by Curtis (4). A mechanism is postulated to explain the formation of the 1,1′-spirobiindane system. The reactions of several polyalkylindenes with α-methylstyrene and triphenylcarbinol were investigated. Several new polyalkyl-1,1′-spirobiindanes and a new polyalkylindene[1,2-a]indene were produced. Two of the 1,1′-spirobiindanes investigated were synthesized by unequivocal methods.
CONTRIBUTION TO THE INFRARED SPECTRA OF ORGANOSULPHUR COMPOUNDS
Authors: Rao C. N. R. , Venkataraghavan R. , Kasturi T. R.
Published: May 2006

Infrared spectra of various types of organosulphur compounds have been examined and group frequencies arising from G—S, S—S, N—S, O—S, and C=S stretching vibrations have been assigned and discussed. The C—S bands of thioketals and S—S bands of tri- and tetra-sulphides show splittings due to vibrational coupling. The O—S and N—S stretching frequencies are found around 890 and 820 cm−1 respectively, values which are much higher than the C—S stretching frequencies. Potassium alkyl xanthates exhibit the asymmetric and symmetric stretching frequencies of the CS2− ion. The splitting of C—O and C=S stretching bands in dialkyl dixanthogens have been interpreted in terms of the Fermi interaction with the combination tone of C—S and S—S stretching vibrations and with the overtone of S—S stretching vibrations respectively. The relative intensity of the C=S stretching bands in a few derivatives show marked dependence on the electronegativities of the elements directly linked to the thiocarbonyl group. It is found that the earlier assignments of the "[Formula: see text] bands" due to mixed vibrations in thioamide type derivatives have been found to be well justified on the basis of the recent normal coordinate treatment. Another band tentatively designated as the "[Formula: see text] IV band" has been assigned for these derivatives in the region 850–680 cm−1. Examination of the spectra of a number of thioamide type derivatives has shown no evidence for the presence of thiol tautomers. All of them exist as thiones exhibiting characteristic N—H absorption and "[Formula: see text] bands".
INFRARED SPECTRA AND CRYSTALLINE PHASE TRANSITIONS OF AMMONIUM NITRATE
Authors: Théorêt A. , Sandorfy C.
Published: May 2006

The infrared spectra of solid crystalline films of ammonium nitrate were measured at temperatures ranging between the melting point (169 °C) and liquid air temperature (−190 °C). Four different spectra were obtained which are shown to belong to phase I, II, IV, and (very probably) VII. Phases III and V were not encountered; only transitions [Formula: see text], [Formula: see text], and [Formula: see text] were observed. A spectrum measured at −190 °C after rapid cooling is shown to correspond to a mixture of phases IV and VII. The symmetry properties of the different phases are discussed in relation with their infrared spectra.
REACTION OF ANHYDROSEPEDONIN WITH ALKALI SYNTHESIS OF A DEGRADATION PRODUCT AND SOME RELATED DIMETHYLHYDROXYBENZOIC ACIDS
Authors: Divekar P. V. , Vining L. C.
Published: May 2006

Two products have been isolated from the reaction of anhydrosepedonin with alkali and identified as 3-hydroxy-5-methyl benzoic acid and 3,4-dimethyl-5-hydroxybenzoic acid. The structure of the latter compound was established by unambiguous synthesis. In the course of this work the remaining o- and m-hydroxybenzoic acids derived from o-xylene were also prepared.
RAPID ANALYSIS OF STRONTIUM AND RUBIDIUM IN MINERALS
Authors: Mills A. A.
Published: May 2006

Methods are described for the rapid analysis of strontium and rubidium in micas and alkali feldspars by emission spectrography. The elements are determined in a common matrix, excess barium carbonate acting as buffer and internal standard. The techniques are applicable to the analysis of 5–500 p.p.m. strontium in the minerals, with relative deviations of ±5–8%. Semiquantitative results are obtained for 100–1500 p.p.m. rubidium in the same materials. These methods have also been successfully applied to the analysis of strontium and rubidium in certain whole rocks. Results obtained with the standard granite G-1 and standard diabase W-1 show satisfactory agreement with the recommended values.
STEREOCHEMICAL CONFIGURATION OF SOME PHTHALIDEISOQUINOLINE ALKALOIDS
Authors: Safe S. , Moir R. Y.
Published: May 2006

not available
THE KINETICS OF REACTION BETWEEN L-CYSTEINE HYDROCHLORIDE AND SOME MALEIMIDES
Authors: Lee C. C. , Samuels E. R.
Published: May 2006

not available
ION–MOLECULE REACTIONS STUDIED BY TIME-OF-FLIGHT MASS SPECTROMETRY
Authors: Hand Clifford W. , Weyssenhoff Hanns von
Published: May 2006

not available
A REMARK ON THE ULTRAVIOLET SPECTRUM OF CHRYSENE
Authors: Sauvageau P. , Sandorfy C.
Published: May 2006

not available
LES ACÉTATES ÉNOLIQUES DES DIMÉTHYL-6,6 ET DIMÉTHYL-7,7 DÉCALONES-2 CIS ET TRANS
Authors: Favre H. , Liston A. J.
Published: May 2006

not available
THE CHROMIC ACID OXIDATION OF ARYL TRIFLUOROMETHYL ALCOHOLS: ISOTOPE AND SUBSTITUENT EFFECTS
Authors: Stewart Ross , Lee Donald G.
Published: May 2006

The mechanism of the chromic acid oxidation of eight aryltrmuoromethylcarbinols has been studied in acetic acid solution. Electron-donating substituents accelerate the reaction and a good correlation of rate with σ+ values has been found. The rho value is −1.01. Deuterium isotope effects for the oxidation of five of these compounds have been determined and the magnitude of the isotope effect has been found to correlate inversely with the ease of oxidation of the alcohol.The results are interpreted in terms of a unimolecular decomposition of the chromate ester of the alcohol.
ON THE EQUILIBRIUM ATTAINED BY ELECTROLYTIC SOLUTIONS UNDER IONIZING RADIATION
Authors: Coleman J. R.
Published: May 2006

not available
SYNTHESIS OF 2- OR 4,6-DINITRO-sec-HEXYL PHENOLS
Authors: Dutton G. G. S. , Hillman M. E. D. , Moffatt J. G.
Published: May 2006

not available
A QUEBRACHAMINE MODEL
Authors: Wenkert Ernest , Garratt Sheila , Dave K. G.
Published: May 2006

not available
THE BROMINATION AND HALOGENOMETHOXYLATION OF D-GLUCAL TRIACETATE
Authors: Lemieux R. U. , Fraser-Reid B.
Published: May 2006

The bromination of D-glucal triacetate gave a mixture of tri-O-acetyl-2-bromo-2-deoxyglycopyranosyl bromides containing about 60% and 30% of the compounds with the α-D-gluco and α-D-manno configurations, respectively. Reaction of the bromides with methanol in the presence of silver carbonate proceeded almost entirely with inversion of the reacting anomeric centers. Hydrogenolysis of the product of methanolysis gave methyl 2-deoxy-β-D-glucopyranoside. Reaction of D-glucal triacetate with either bromine, chlorine, or iodine in methanol containing silver acetate gave in each case about 60–65% and 35–40% yields of the corresponding methyl 2-deoxy-2-halogeno-α-D-mannopyranoside and -β-D-glucopyranoside triacetates. The mechanisms of the reactions are discussed.
KINETICS OF ETARD'S REACTION: PART III. EFFECT OF RING SUBSTITUTION
Authors: Stairs R. A.
Published: May 2006

The initial rates of reaction of a number of para- and meta-substituted toluenes with chromyl chloride in carbon tetrachloride solution have been measured and the results analyzed using Hammett's relation. The results are interpreted in terms of electrophilic attack by CrO2Cl2 molecules. The reaction appears to be marked by an unusually large effect of ring substitution on the entropy of activation. The mechanistic significance of this observation is discussed.
FATTY ACID COMPOSITION OF SOME CUCURBITACEAE SEED OILS
Authors: Chisholm Mary J. , Hopkins C. Y.
Published: May 2006

Seed oils of nine species of Cucurbitaceae were analyzed by gas chromatography and other techniques. The oil of Ecballiumelaterium yielded 22% of punicic acid; Cucumisdipsaceus and Cucurbitaficifolia had the ordinary palmitic–oleic–linoleic composition; a variety of Momordicacharantia had 57% of α-eleostearic acid. Occurrence of punicic acid as the major acid of Trichosanthesanguina was confirmed. No evidence could be found for the existence of an isomer of linoleic acid in Telfairiapedata oil. The fatty acid composition was determined quantitatively for the above oils and for those of Cucumismelo, Lagenariasiceraria, and Luffacylindrica. The 4-bromophenacyl esters of α-eleostearic and punicic acids were prepared.
ANTINEOPLASTIC AGENTS: X. N-BIS(2-FLUOROETHYL)AMINES
Authors: Pettit George R. , Smith Robert L.
Published: May 2006

Successive conversion of N-bis(2-hydroxyethyl)-p-toluenesulphonamide (Ib) to respective dimethanesulphonate and difluoro derivatives (IIa, IIIa, and IIIc) was found to provide a convenient route to N-bis(2-fluoroethyl)amine. Reaction of N-bis(2-methanesulphonyl-oxyethyl)-p-toluenesulphonamide (IIIa) with limited quantities of potassium fluoride, in several pro tic solvents, was shown to yield N-(p-toluenesulphonyl)morpholine (IV). Utility of N-bis(2-fluoroethyl)amine as a precursor of fluoro-nitrogen mustards was illustrated by synthesis of two N-bis(2-fluoroethyl)benzylamines (IXb and Xa). Application of an aluminum chloride – lithium aluminum hydride reagent for hydrogenolysis of carbon–fluorine bonds was also suggested.
FRIEDEL–CRAFTS REARRANGEMENTS: II. REARRANGEMENTS DURING CYCLIALKYLATION OF ε-ARYL-SUBSTITUTED COMPOUNDS
Authors: Barclay L. R. C. , Ginn B. A. , Milligan C. E.
Published: May 2006

Friedel–Crafts cyclialkylation of aromatics such as 1,1,4,4-tetramethyltetralin with 2,6-dichloro-2,6-dimethylheptane does not yield a benzsuberane as previously reported. Several 5-phenyl-substituted chlorides, alcohols, and olefins were synthesized for cyclialkylation studies. These included 2-chloro-2,6-dimethyl-6-phenylheptane (Xa), 3-chloro-3,7-dimethyl-7-phenyloctane (Xb), 2,6-dimethyl-6-phenyl-2-heptanol, 2,6-dimethyl-6-phenyl-2-hepten-4-one (XX), 2-chloro-6-methyl-6-phenylheptane, and 1-chloro-5-phenylpentane (XXIV). Cyclialkylation of Xa (and the corresponding alcohol), Xb, 2-chloro-6-methyl-6-phenyl-heptane, and XXIV produced alkyltetralins instead of benzsuberanes. Evidence is presented and discussed which indicates that the alkyltetralins form by rearrangements in the side chains of the aryl-substituted systems. The alternative mechanism involving rearrangement of a benzsuberane intermediate via a phenonium ion mechanism was unequivocally ruled out in at least one case—the cyclization of Xb. Nuclear magnetic resonance evidence is presented for the structural assignments.
TOTAL SYNTHESIS OF STEROIDAL DERIVATIVES: III. SYNTHESIS OF HYDROCHRYSENE ANALOGUES AND RELATED COMPOUNDS
Authors: Kutney James P. , By Arnold
Published: May 2006

A synthetic sequence leading to the total synthesis of certain octahydrochrysene derivatives is described. The introduction of a ketonic function into ring B of these substances is also given and it is noted that these ketone intermediates allow entry into ring-B-modified steroidal analogues. The sequence indicates an interesting difference in the mode of reaction of cis–syn–cis and trans–anti–trans hydrochrysene analogues, which is undoubtedly due to the difference in the conformational structures of these compounds.
ISOTOPE EFFECTS IN METHYL RADICAL ABSTRACTION REACTIONS
Authors: Salomon Mark
Published: May 2006

The high kH/kD ratio found experimentally for methyl radical abstraction reactions is explained on the basis of classical rate theory. It is shown that if the bending frequencies in the activated complex approach zero, good agreement is found between experimental and calculated kH/kD values. For abstraction of H and D from hydrocarbons, both the tunneling and classical rate theories predict acceptable kH/kD values. Abstraction of H and D from H2 and D2, however, can best be explained on the basis of a classical process.
THE THERMAL REVERSIBILITY OF THE MICHAEL REACTION: II. NITROKETONES AND RELATED COMPOUNDS
Authors: Allen C. F. H. , Happ G. P.
Published: May 2006

In continuation of the study of the thermal reversibility of Michael adducts, 13 γ-nitroketones were examined in the mass spectrometer, using the inlet heated at 230°. The presence of furans was indicated, arising from the intact molecule. Such remotely related substances would never have been envisaged had not the mass spectrum been available. In contrast to the behavior of delta ketonic nitriles (Part I) only normal retrogression was found. There were many secondary products resulting from extensive decomposition of the expected nitro addend. Not all the products can be isolated by classical procedures, but their presence is predictable, and can be shown by the use of the mass spectrometer. Nine simple nitro- and bromonitro-ethylenes, sensitive to heat alone, were unexpectedly stable in the heated inlet of the mass spectrometer, but did give rise to very small amounts of decomposition products. Phenyl- and 1-naphthyl-nitromethanes, which decomposed completely, gave comparable types of products. Most of these nitro compounds have previously been thermally treated by classical methods.
THE SOLUTION PROPERTIES OF SOME POLYOXYETHYLATED NONIONIC SUBSTANCES IN AQUEOUS AND IN NONAQUEOUS SOLVENTS
Authors: Sirianni A. F. , Coleman R. D.
Published: May 2006

Unlike sorbitan and glycerol monostearates, alkylphenol derivatives of polyoxytheylene appear to be monodisperse in benzene when the solutions were examined by vapor pressure lowering. In addition, the existence of micelles was not detected by light-scattering measurements in benzene with a few representative samples. In agreement with light-scattering data, the number average micellar weight in water decreased with increasing number of ethylene oxide units per molecule. A difference of about a factor of 8 between weight and number average molecular weight appears to exist for materials of similar composition.
A NEW SYNTHESIS OF ARYLPYRROLES
Authors: Allen C. F. H.
Published: May 2006

not available
THE SIGNS OF THE H′—G—H′ AND H′—C—O—H′ NUCLEAR MAGNETIC RESONANCE COUPLING CONSTANTS
Authors: Hruska F. , Schaefer T. , Reilly C. A.
Published: May 2006

not available
VAPOR PRESSURE MEASUREMENTS ON THE SYSTEM D2O–H2O. ANALYSIS OF D2O–H2O MIXTURES
Authors: Mazurek M. , Perlin A. S.
Published: May 2006

not available
THE PHOTOLYSIS OF WATER VAPOR AND REACTIONS OF HYDROXYL RADICALS
Authors: Ung A. Y.-M. , Back R. A.
Published: May 2006

The photolysis of water vapor at 1849 Å has been investigated as a possible source of hydroxyl radicals for kinetic studies. At temperatures from 23 to 350 °C and pressures from 1.3 to 28 mm, H2 and H2O2 were the only detectable products. Experiments with added oxygen indicated that O2 may have been present as an intermediate at a very low steady-state concentration, although this is not certain. Possible mechanisms are discussed.At temperatures from 200 to 350 °C, carbon monoxide appeared to react quantitatively with the hydroxyl radicals produced in the photolysis of water by the reaction, [Formula: see text] Rates of this reaction relative to those of the reactions, [Formula: see text] and [Formula: see text] were estimated from the decrement in the yield of CO2 when H2 or D2 was added to the H2O–CO system, and the following Arrhenius parameters were obtained:[Formula: see text]At temperatures below 200 °C, hydroxyl radicals were not completely converted to CO2, as the yield of CO2 increased to a maximum, then decreased again, with increasing pressure of CO. The mechanism of this system is complex, but probably involves secondary reactions of HCO or COOH radicals.
TWO NEW PAPILIONACEOUS ALKALOIDS: ARGYROLOBINE AND (−)-APHYLLIDINE
Authors: Tsuda Y. , Marion Léo
Published: May 2006

Argyrolobiummegarhizum Bol. has been found to contain a number of alkaloids, four of which have been well characterized. Two of these were identical with N-methylcytisine and cytisine respectively, while the other two were new. One of these proved to be the levorotatory enantiomorph of aphyllidine, while the other (the major alkaloid), C15H22O2N2, designated argyrolobine, was shown to be a hydroxyaphyllidine, and its absolute configuration derived by reduction to (−)-sparteine.
AN INFRARED STUDY OF THE ADSORPTION OF AMMONIA ON POROUS VYCOR GLASS
Authors: Cant N. W. , Little L. H.
Published: May 2006

The infrared spectrum of ammonia adsorbed on porous glass at 20 °C and 150 °C has been studied in the region 1450–4000 cm−1. No absorption band due to the asymmetric bending mode of ammonia was observed but in the NH stretching region, bands occurred at 3280 cm−1, 3320 cm−1, 3365 cm−1, and 3400 cm−1. The bands at 3320 cm−1 and 3400 cm−1 were easily removed by evacuation and are due to ammonia molecules hydrogen bonded through the nitrogen atom to surface hydroxyl groups. The bands at 3280 cm−1 and 3365 cm−1 were not removed by evacuation even at 150 °C and are due to ammonia molecules held to surface Lewis acid sites by the nitrogen lone-pair electrons. The site for this adsorption is not a surface hydroxyl group. These results are further evidence for the existence of the two adsorption sites proposed by Folman and Yates. Deuteration of the surface OH groups was easily accomplished with D2O vapor at 300 °C and the rate of hydrogen exchange between adsorbed ammonia molecules and surface OD groups was found to be rapid.
THERMOCHEMICAL STUDIES OF SOME ACRYLATE AND METHACRYLATE POLYMERIZATIONS IN EMULSION SYSTEMS
Authors: McCurdy K. G. , Laidler K. J.
Published: May 2006

With the use of a Tian–Calvet microcalorimeter, the heats of polymerization of a number of monomers have been measured in aqueous emulsion systems: the emulsifying agent was cetyltrimethylammonium bromide, and initiation was by Fenton's reagent (Fe++ + H2O2). The monomers employed were acrylic acid, methyl, ethyl, and butyl acrylates, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methacrylic acid, and methyl, ethyl, butyl, and hexyl methacrylates. The heats of polymerization lie in the range from 13 to 19 kcal per mole, the experimental standard deviations being 40 to 110 cal per mole. A steady increase was observed for acrylic acid and its CH3, C2H5, and C4H9 esters, and for methacrylic acid and its CH3, C2H5, C4H9, and C6H13 esters. This change is attributed to a steady increase in the proportion of head-to-head, tail-to-tail polymers, leading to a decrease in steric hindrance. Abnormally low heats observed with hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate are attributed to the solvation of the monomer, less solvation being possible in the polymer as a result of shielding.
EXTRACELLULAR GLYCOLIPIDS OF RHODOTORULA SPECIES: THE ISOLATION AND SYNTHESIS OF 3-D-HYDROXYPALMITIC AND 3-D-HYDROXYSTEARIC ACIDS
Authors: Tulloch A. P. , Spencer J. F. T.
Published: May 2006

Several species of the red yeast Rhodotorula produce extracellular glycolipids which consist of a mixture of mannitol and pentitol esters of 3-D-hydroxypalmitic and 3-D-hydroxystearic acids. One molecule of the long chain acid is attached to each polyol molecule and most of the remaining hydroxyl groups including the one on the fatty acid are acetylated.
PYRIDINE N-OXIDE COMPLEXES OF ZIRCONYL, THORIUM, AND URANYL PERCHLORATES
Authors: Murthy P. Rama , Patel C. C.
Published: May 2006

Pyridine N-oxide complexes having the composition ZrO(Py•O)6(ClO4)2, Th(Py•O)8(ClO4)4, and UO2(Py•O)5(ClO4)2 have been prepared. The infrared and electronic absorption spectra show that the bonding between the metal and pyridine N-oxide in the complexes has occurred by donation of the lone pair of p-electrons on oxygen to the metal, and that the π-bond character of NO group increases in the complexes as uranyl < thorium < zirconyl. The decrease in the vibrational structure of the UO22+ spectrum in the visible region indicates strong coordination of pyridine N-oxide to the uranyl group. The decomposition temperatures of zirconyl, thorium, and uranyl complexes are 307, 350, and 319 °C respectively.
THE CHEMISTRY OF ALUMINUM–NITROGEN COMPOUNDS: IV. THE REACTIONS OF Me3Al AND H3Al:NMe3 WITH SEVERAL TERTIARY POLYAMINES
Authors: Fetter Neil R. , Moore Donald W.
Published: May 2006

The reactions of Me3Al with Me2N(CH2)3NMe2, Me2NCH2CH=CHCH2NMe2, (CH2)6N4, and (Me2N)2C=C(NMe2)2 have yielded complexes with two molecules of Me3Al per amine. The structures of these complexes are rationalized on the basis of a pentacoordinated aluminum atom with a linear N → Al← N dative bond. The reactions of H3Al:NMe3 with these amines have produced a variety of products in which the amines appear to have undergone rearrangements. The complexes are 1:1 except the (Me2N)2C=C(NMe2)2 complex, which has 2 moles of H3Al per amine.
CARBOHYDRATES OF CENTROSEMA SEED. THE CONSTITUTION OF AN ARABINO GALACTAN. I
Authors: Unrau A. M.
Published: May 2006

Treatment of the water-soluble polysaccharides of Centrosemaplumari seed with Fehling's solution resulted in the formation of a precipitate in major proportions. The polysaccharide forming a copper complex was composed of D-galactose (92.5%) and L-arabinose (7%). No change was observed in this ratio upon further treatment of the polysaccharide with Fehling's solution. Partial hydrolysis of the arabinogalactan liberated about 80% of the arabinose. Controlled periodate degradation (Smith degradation) indicated a complex branched structure with a preponderance of 1,4-glycosidic linkages. Methylation experiments also indicated a branched structure.
N.M.R. SPECTRA OF TIN COMPOUNDS: II. Sn119 AND H1 MAGNETIC RESONANCE SPECTRA OF HEXAMETHYLDITIN
Authors: Clark H. C. , Kwon J. T. , Reeves L. W. , Wells E. J.
Published: May 2006

The H1 and Sn119 resonances in hexamethylditin have been examined. A coupling constant J = 4400 ± 70 c.p.s. is reported for Sn117—Sn119 nuclei directly bonded. Comparison with some other heavy metal couplings is made. Changes in bond type of the Sn—C bond in hexamethylditin from tetrahedrally bonded tin compounds with no Sn—Sn bond is indicated by an anomalously low value for JSn–C–H•
ON THE PORE STRUCTURE OF VYCOR GLASS
Authors: Basmadjian D. , Chu K. P.
Published: May 2006

not available
POLYMER FORMATION IN THE RADIOLYSIS OF BENZENE–CYCLOHEXANE MIXTURES
Authors: Stone J. A. , Dyne P. J. , Bailey M. G.
Published: May 2006

not available
CATALYTIC OXIDATION OF LEAD (II) ACETATE BY OZONE
Authors: Shulman Garson P.
Published: May 2006

not available
PRESSURE EFFECT AND MECHANISM IN THE ACID-CATALYZED HYDRATION OF PROPYLENE AND ISOBUTYLENE
Authors: Baliga B. T. , Whalley E.
Published: May 2006

The effect of pressure up to 3 kbar on the rate of the acid-catalyzed hydration of propylene and isobutylene has been measured. The volumes of activation are: for propylene at 100 °C−9.6 ± ~1.0 cm3 mole−1, and for isobutylene at 35 °C− 11.5 ± ~1.0 cm3 mole−1. The effect of temperature in the range 90–120 °C on the rate of hydration of propylene at 100 bar was measured. At 100 °C the Arrhenius energy is 27.1 ± ~1.0 kcal mole−1 and the entropy of activation is −5.4 ± ~2.5 cal deg−1 mole−1. Both the volumes and entropies of activation strongly indicate that a molecule of water is present in the transition states, which can therefore be represented as [olefin. H+•H2O]≠. There appears to be no strong evidence regarding the molecular structure of the transition states.
GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART X. THE VOLATILE OILS OF THE LEAVES OF SITKA AND ENGELMANN SPRUCE
Authors: RUDLOFF E. VON
Published: May 2006

The leaf oils from Sitka and Engelmann spruce were obtained in 0.36 and 0.094% yield respectively. The average percentage composition was determined by gas–liquid chromatography. Sitka spruce leaf oil was found to contain mainly d-myrcene (23.5%), l-piperitone (23.2%), and d-camphor (17.2%). Smaller amounts of 1,8-cineole, l-β-phellandrene, p-cymene, two aliphatic esters, d-bornyl acetate, d-borneol, and d-terpinen-4-ol were also isolated and several other esters appeared to be present in small amounts. Engelmann spruce leaf oil was found to contain mainly cis-hex-3-en-1-ol (18.5%), d-camphor (16.0%), d-bornyl acetate (8.6%), d-linalool (5.8%), and two unidentified compounds. Smaller amounts of myrcene, β-phellandrene, p-cymene, piperitone, and several sesquiterpenoids were also recorded. Tricyclene, α-pinene, camphene, β-pinene, 3-carene, limonene, γ-terpinene, and terpinolene were found in small amounts in both oils.Phylogenetic relationships between the different spruces and other conifers are discussed.
STUDIES IN THE PYRROLINE SERIES: III. SOME PYRROLINYLPYRROLES AND RELATED COMPOUNDS
Authors: Bonnett R. , Chan K. S. , Gale I. A. D.
Published: May 2006

The addition of 5,5-dimethyl-1-pyrroline to pyrrole gives both the 1:1 adduct and the 2:1 adduct. The palladium-catalyzed dehydrogenation of 2,2′-pyrrolidinylpyrrole has been studied at various temperatures. In refluxing toluene the reaction proceeds satisfactorily to the pyrroline level, while in cymene the corresponding bipyrrole is produced. 1,2′-(1′-Pyrrolinyl)-pyrrole has been obtained from the reaction of 2-methoxy-1-pyrroline with pyrrole: on pyrolysis it yields 2,2′-(1′-pyrrolinyl)pyrrole. A similar sequence is observed with 3,4-dimethylpyrrole.
THE RESPONSE TO 14 MEV NEUTRONS OF SOME CHEMICAL DOSIMETER SYSTEMS
Authors: Armstrong W. A. , Humphreys W. G.
Published: May 2006

The response to 14 Mev neutrons of 10−3 M ferrous sulphate −0.4 M H2SO4, 10−4 M ceric sulphate −0.4 M H2SO4, 10−3 M calcium benzoate, and 10−1 M terephthalic acid −4 × 10−4 M NaOH solutions has been investigated. G values as follows:G(Fe III) = 10.5 ± 0.2, G(Ce III) = 3.13 ± 0.06, G(salicylic acid) = 0.316 ± 0.006, and G(hydroxyterephthalic acid) = 0.474 ± 0.007. These results are compared with those obtained when the same solutions are irradiated with Co60 γ-rays. Although the response to 14 Mev neutrons is only about one half the response of Co60 γ-radiation, the calcium benzoate and the terephthalic acid systems can measure doses as low as 20 and 2 rads, respectively.
SYNTHESIS OF MALTOBIOURONIC ACID (4-O-[α-D-GLUCOPYRANOSYLURONIC ACID]-D-GLUCOSE)
Authors: Dutton G. G. S. , Slessor K. N.
Published: May 2006

Benzyl β-maltobiouronic acid has been isolated from the catalytic oxidation of benzyl β-maltoside. Hydrogenolysis of the benzyl glycoside afforded maltobiouronic acid which was characterized as the methyl ester heptaacetate.
THE SULPHURIC ACID SOLVENT SYSTEM: PART VI. THE BASICITIES OF COMPOUNDS CONTAINING SULPHUR–OXYGEN BONDS
Authors: Hall S. K. , Robinson E. A.
Published: May 2006

Cryoscopic and conductimetric studies of a variety of compounds containing S—O bonds have shown that dimethyl sulphoxide behaves as a strong base in sulphuric acid whereas dialkyl sulphones behave as weak bases. In contrast diaryl sulphones and aryl sulphonic acids behave as non-electrolytes.A correlation is established between the basicities of the alkyl sulphones, H2SO4, and the HSO4− ion, and their sulphur–oxygen stretching frequencies. This relation is used to predict the basicities of other compounds containing S—O bonds. In particular it is shown that the basicity of monomeric sulphur trioxide is similar to that of sulphuric acid, and sulphamide is shown to behave as a strong base in sulphuric acid, which implies protonation on a nitrogen atom rather than on oxygen, since the S—O stretching frequencies indicate only weakly basic behavior for O-protonation.
PERFLUOROALKYL ARSENICALS: PART IX. SOME REACTIONS OF COMPOUNDS CONTAINING As–As BONDS
Authors: Cullen W. R. , Hota N. K.
Published: May 2006

Arsenobenzene reacts with CF3I to give C6H5As(CF3)2, C6H5As(CF3)I, and C6H5AsI2. C6H5As(CF3)I and AgCl yield C6H5As(CF3)Cl. The compounds CF2=CFX react with (CH3)2As—As(CH3)2 under mild conditions to give 1:1 adducts (CH3)As—CF2CFX—As(CH3)2 (X = CF3, Br). Some (CH3)2As—CF=CF2 is produced when X = Br and is the major product when X = I. When X = F a 1:4 adduct (CH3)2As—(CF2CF2)4—As(CH3)2 is probably formed on ultraviolet irradiation. (CH3)2As—As(CH3)2 reacts with CF3C≡CCF3 to give cis and trans (CH3)2AsC(CF3)=C(CF3)As(CH3)2 and with [Formula: see text] to give (CH3)2AsF and [Formula: see text].
FORMATION CROSS SECTIONS OF VARIOUS RADIONUCLIDES FROM Ni, Fe, Si, Mg, O, AND C FOR PROTONS OF ENERGIES BETWEEN 130 AND 400 MEV
Authors: Rayudu Garimella V. S.
Published: May 2006

Formation cross sections of Co56, Mn54, Mn52, Cr51, V48, P32, and Be7 from Fe and Ni; of Na24, Na22, and Be7 from Si and Mg; and of Be7 from C and O have been measured for incident protons of energies between 130 and 400 Mev to assist in the interpretation of data on cosmic-ray-produced nuclides in iron and stone meteorites. Formation cross sections of Mn54, Mn52, Cr51, V48, and P32 are found to be a factor of 2 to 3 lower from Ni than from Fe, whereas those of Co56 are 20- to 50-fold higher than from Fe. Be7 cross sections from C are found to be almost the same as from O, within experimental uncertainties. Cross sections of Na24 and Na22 from Mg and Si are found to be relatively energy independent, whereas those of P32 and Be7 from Ni and Fe are found to increase rapidly with increasing energy. Some qualitative conclusions are drawn about the production of cosmogenic activities in meteorites.
FIELD DEPENDENCE AND ANOMALOUS TEMPERATURE DEPENDENCE OF TAFEL SLOPES FOR PROCESSES OCCURRING AT HIGH ELECTROSTATIC FIELDS
Authors: Dignam M. J.
Published: May 2006

A consideration of the probability per unit time for the transport of a charged species over a potential barrier in the presence of a high external electrostatic field shows that the net activation energy for such a process is in general a complex function of the field strength. Both the field dependence and the anomalous temperature dependence of the Tafel slope for the steady-state anodic oxidation of Ta, Nb, and Al are accounted for quantitatively by a simple model according to which the field independent component of the potential energy function for displacement of a mobile charged species is assumed to resemble a Morse function. Accordingly, the steady-state anodic oxidation data for these metals may be represented within experimental error by only three empirical constants, the pre-exponential factor, the activation energy, and the Morse function distance parameter. If, in place of a Morse function, a parabolic or cosine potential energy function is assumed, less satisfactory agreement with the data is obtained. Although there is some doubt concerning the uniqueness of the Morse function in explaining the data, there is no doubt that the present considerations are able to account entirely for the anomalous Tafel slope behavior.
VAPOR-PHASE RADIOLYSIS OF CYCLOHEXANE AND MIXTURES OF BENZENE AND CYCLOHEXANE
Authors: Blachford J. , Dyne P. J.
Published: May 2006

The vapor-phase radiolysis of cyclohexane and benzene-cyclohexane mixtures has been studied with isotopic tracer techniques using C6D12 and C6D6. Benzene does not quench the molecular detachment of hydrogen, [Formula: see text] but interacts with the second-order processes giving HD in C6D12–C6H12 mixtures. This interaction is not H-atom scavenging and an ionic mechanism is preferred. The radiolysis of all these systems is very different from their liquid-phase radiolysis.
AN ESTIMATE OF THE HYDRONIUM ION ACTIVITY IN CONCENTRATED ACIDS
Authors: Yates Keith
Published: May 2006

not available
TRANSFER CELL FOR GAS CHROMATOGRAPHY
Authors: Bednas M. E. , Russell D. S.
Published: May 2006

not available
EXOCELLULAR BACTERIAL POLYSACCHARIDE FROM XANTHOMONAS CAMPESTRIS NRRL B-1459: PART III. STRUCTURE
Authors: Sloneker J. H. , Orentas Danute G. , Jeanes Allene
Published: May 2006

Periodate oxidation showed that the O-acetyl groups in the polysaccharide sterically affected the rate but not the extent of oxidation of the D-mannose residues, two-thirds of which were glycosidically substituted at C2by a D-glucuronic acid residue and one-third of which was linked as a terminal side-chain residue. The D-glucose and D-glucuronic acid residues oxidized by periodate were substituted at C4, but both were more resistant to oxidation than were the D-mannose residues. One-third of the D-glucose residues and a significant quantity of the D-glucuronic acid residues were inert to vigorous periodate oxidation and may bear side-chain residues. Quantitative recovery of the periodate-stable D-glucose residues as 2-O-β-D-glucopyranosyl-D-erythritol, after the oxidized polysaccharide was reduced with sodium borohydride and hydrolyzed with mild acid, revealed that two-thirds of the D-glucose residues were in pairs linked (β, 1 → 4). The pyruvic acid linkage in the polysaccharide was established as a 4,6-O-1-carboxyethylidene ketal attached to a terminal D-glucose side-chain residue. The structure of the polysaccharide is discussed in relation to its anomalous viscosity behavior in salt solutions.
PYRROLE CHEMISTRY: III. FRIEDEL-CRAFTS ISOPROPYLATION OF METHYL 2-PYRROLECARBOXYLATE
Authors: Anderson Hugh J. , Hopkins L. Cameron
Published: May 2006

The reaction between isopropyl chloride and methyl 2-pyrrolecarboxylate catalyzed by aluminum chloride has been investigated. From the reaction mixture 4-isopropyl-, 5-isopropyl-, and 4,5-diisopropyl-2-esters have been isolated and identified. It has been found that while the 4-isopropyl-2-ester rearranged to 5-isopropyl-2-ester under alkylation conditions, neither the latter nor the 4,5-diisopropyl-2-ester underwent any change. Some suggestions as to the course of the reaction are made.
THE STRUCTURES OF GALACTOSYL-LACTOSE AND GALACTOBIOSYL- LACTOSE PRODUCED FROM LACTOSE BY SPOROBOLOMYCES SINGULARIS
Authors: Gorin P. A. J. , Spencer J. F. T. , Phaff H. J.
Published: May 2006

Sporobolomycessingularis, when grown in a medium containing lactose, utilized the glucose portion as a carbon source and produced by transglycosylation as main products a trisaccharide O-β-D-galactopyranosyl-(1 → 4)-O-β-D-galactopyranosyl-(1 → 4)-D-glucose (I) and a tetrasaccharide O-β-D-galactopyranosyl-(1 → 4)-O-β-D-galactopyranosyl-(1 → 4)-O-β-D-galactopyranosyl-(1 → 4)-D-glucose (II) (50% combined yield). Oligosaccharides of higher molecular weight were not detected.
THE DIELECTRIC BEHAVIOR OF THE SYSTEM: ACETIC ACID – CHLOROFORM – WATER AT 25 °C
Authors: Campbell A. N. , Gieskes J. M. T. M.
Published: May 2006

The dielectric constants of mixtures of water and acetic acid, of chloroform and acetic acid, and of water, chloroform, and acetic acid have been determined at 25 °C, over a range of concentrations. The apparent molar polarizations, but not the dipole moments, of acetic acid have been calculated and the results interpreted in the light of an assumed structure of the mixtures.
BASE-CATALYZED DIMERIZATIONS OF ALKYLIDENEMALONONITRILES
Authors: Weir Mary R. S. , Hyne J. B.
Published: May 2006

The base-catalyzed dimerizations of several alkylidenemalononitriles have been studied, and proton nuclear magnetic resonance (n.m.r.) spectral evidence is presented in support of the suggested cyclic structures of these dimers.
THE ELECTRICAL POLARIZATION OF 1,4-BENZOQUINONE AND RELATED SUBSTANCES
Authors: Huber Helmut , Wright George F
Published: May 2006

A determination of the atom polarization of 1,4-benzoquinone from low-frequency infrared absorptions does not confirm the results of Becker and Charney. Therefore the total polarization of this substance must partly be due to orientation of a dipole. Also tetracyanoethylene and tetracyanoquinodimethane seem to have appreciable dipole moments although they both have abnormally high distortion polarization.
MOLECULAR SIEVE SORBENTS FROM CLINOPTILOLITE
Authors: Barrer R. M. , Makki M. B.
Published: May 2006

Clinoptilolite has been investigated as a source of porous, largely crystalline, molecular sieve sorbents. By treating the zeolite with mineral acid of different strengths a range of high area sorbents has been produced, in which all the original cations have been replaced by hydronium ions, and in which the aluminum has been progressively removed from the frameworks. The new sorbents and the original clinoptilolite have been characterized by sorption studies, and by X-ray, electron optical, differential thermal analysis, and thermogravimetric methods. The most open molecular sieve sorbents, able to imbibe considerable amounts of larger molecules such as benzene and isopentane, were obtained using 1 N and 2 N acid, but as acid strength increased further there was a decline in both crystallinity and sorption capacity until with 30 N acid an amorphous product resulted.
DIRECT CONVERSION OF AROMATIC NITRILES INTO PHTHALIMIDINES AND UREAS USING DICOBALT OCTACARBONYL
Authors: Rosenthal Alex , Gervay J.
Published: May 2006

not available
THE MOLECULAR CONFORMATION OF TRIPHENYLARSINE
Authors: Aroney M. J. , Fèvre R. J. W. Le , Saxby J. D.
Published: May 2006

not available
COMPOUNDS OF THE TYPE M5X2: Pd5As2, Ni5Si2, AND Ni5P2
Authors: Saini G. S. , Calvert L. D. , Taylor J. B.
Published: May 2006

Space group, lattice parameters, and powder data indicate that Pd5As2 Ni5Si2, and Ni5P2 are structurally related. Single crystal studies have established that Pd5As2 exhibits polytypism. Pd5As2 has a = 7.31 ± 0.01 Å but c-values of 13.7, 10.34, 27.48, and 96.2 Å were observed on different crystals corresponding to a "single layer" repeat distance of 3.43 Å along the c-axis. The last three cells have trigonal symmetry, space group [Formula: see text], [Formula: see text], P3m1 [Formula: see text], or P321 [Formula: see text] and the first cell has hexagonal symmetry, space group P6322[Formula: see text]. The Guinier focussing camera pattern of polycrystalline Pd5As2 can be indexed on a hexagonal cell with a = 7.320 ± 0.002, c = 96 Å. Single crystal and focussing camera studies of Ni5Si2 showed it to be of trigonal symmetry with a = 6.68 ± 0.02, c = 12.28 ± 0.03 Å, and space group P321, P3m1, or [Formula: see text]. A Guinier pattern of Ni5P2 can be indexed with hexagonal parameters a = 13.220 ± 0.002 Å, c = 24.632 ± 0.002 Å; a subcell with a = 6.610 and c = 12.316 Å can be used to index the strong lines. Comparison of the powder data for Pd5As2, Ni5Si2, and Ni5P2 with previously published data for Ni5As2 and Mn5Ge2 shows that the compounds are structurally related.
THE RELATIVE ACCEPTOR POWER OF BORON TRIHALIDES AND BORANE TOWARD TRIMETHYLAMINE BY PROTON N.M.R. MEASUREMENTS
Authors: Miller J. M. , Onyszchuk M.
Published: May 2006

Proton n.m.r. spectra of trimethylamine adducts of the boron trihalides and borane have been measured in chloroform solution. Chemical shifts of methyl protons relative to tetramethylsilane decrease in the order: BBr3 > BCl3 > BH3 > BF3, suggesting that this is the order of acceptor activity toward trimethylamine. This is supported by the existence of a linear relationship between methyl proton chemical shifts and the heats of formation, dipole moments, or infrared vibrational shifts of boron trihalide and borane adducts. Splitting of methyl proton resonances into quartets have been observed for (CH3)3N•BCl3 and (CH3)3N•BBr3 but not for (CH3)3N•BF3 and (CH3)3N•BH3.
N.M.R. STUDIES: PART VI. THE COMPLETE ANALYSIS OF THE PROTON SPECTRA OF TWO ISOMERIC METHYL FLUOROBROMOPROPANOATES WITH THE AID OF HETERONUCLEAR SPIN DECOUPLING
Authors: Stothers J. B. , Talman J. D. , Fraser R. R.
Published: May 2006

The 60 Mc/s proton spectra of methyl 2-bromo-3-fluoropropanoate and the 3-bromo-2-fluoro isomer have been analyzed completely with the aid of heteronuclear spin decoupling to illustrate an extension of the double resonance technique to ABCX spin systems. These results provide confirmatory evidence of the magnitude and relative signs of geminal and vicinal proton–proton and proton–fluorine coupling constants.