bluuebunny/crossref_metadata_2025 huggingface dataset:
FLUORIDE COMPLEXES OF GERMANIUM (IV) IN AQUEOUS SOLUTION
Authors: Benoit R. L. , Place J.
Published: May 2006

The germanium (IV) – fluoride species in various acid media have been investigated by solvent extraction, solubility, and potentiometric methods. The results are interpreted in terms of a series of mononuclear fluorohydroxygermanium (IV) species in which the number of fluorides bound per germanium tends to a maximum value of 5. The formation curve in 0.50 M perchloric acid is explained in terms of stability constants of species [Formula: see text] and [Formula: see text]
PREMELTING PHENOMENA IN LONG-CHAIN FATTY ACIDS
Authors: Barr M. R. , Dunell B. A. , Grant R. F.
Published: May 2006

Nuclear magnetic resonance spectra and the infrared absorption between 700 and 750 cm−1 have been observed at temperatures near the melting points of the even-numbered fatty acids from C18 to C10. The results are interpreted as indicating breakdown of crystalline character and onset of liquid-like motion at scattered points in the solid structure several degrees below the melting point, and increasing in extent as the melting point is approached.
THE PHOTOLYSIS OF TRIFLUOROACETIC ACID VAPOR
Authors: Mearns A. M. , Back R. A.
Published: May 2006

The photolysis of CF3COOH vapor has been studied at temperatures between about 90 and 190 °C, using light of wavelengths between 2000 and 2200 Å. The major products were CO2 and C2F6, with smaller amounts of CO, H2, and CF3H. A marked reduction in the yields of CO2, CO, and H2 with increasing pressure of added isobutane or 1-butene has been interpreted to imply the presence of free COOH radicals in the system, which is supported by the tentative identification of formic and oxalic acids as products of the photolysis. It is thought that the reaction[Formula: see text]represents the main primary photolytic process, with the minor processes[Formula: see text]and[Formula: see text]accounting for no more than 27 and 7% respectively of the total at 165 °C.Some tentative conclusions have been drawn about the reactions of COOH radicals. In the present system, the disproportionation reaction,[Formula: see text]appears to predominate, with the decomposition reaction,[Formula: see text]apparently of minor importance at 165 °C.
PERIODATE OXIDATION OF MESQUITE GUM
Authors: Dutton G. G. S. , Unrau A. M.
Published: May 2006

Mesquite gum was subjected to the Smith procedure involving periodate oxidation, reduction, and mild hydrolysis. The main D-galactose chain was fragmented to a greater extent than expected. The quantity of glycerol formed indicated the presence of a considerable number of 1 → 6 linkages while the formation of threitol showed the presence of 1 → 4 linkages. Several small oligosaccharides terminated by a glycerol residue were isolated together with an oligosaccharide of D.P. 30. Further periodate oxidation of the latter gave a product with D.P. 24 which was in turn oxidized to a compound consisting largely of D-galactose and glycerol. Reduction of the acidic fraction gave mainly 2-O-methyl-D-erythritol.
ELECTRODE PROCESSES WITH A PRECEDING CHEMICAL REACTION: EFFECT OF THE DIFFUSE DOUBLE LAYER
Authors: Rangarajan S. K.
Published: May 2006

The effect of migration in the diffuse double layer on the concentration field of the reactive species is analyzed assuming that the electrode reaction [Formula: see text] is preceded by a chemical reaction [Formula: see text] (ZX = 0). Comparison is made with the solutions derived already by Hurwitz and also by Matsuda for particular cases.
THE INFRARED SPECTRA OF TRIMETHYL ALUMINUM, DIMETHYL ALUMINUM CHLORIDE, METHYL ALUMINUM DICHLORIDE, METHYL TITANIUM TRICHLORIDE, DIMETHYL TITANIUM DICHLORIDE, AND SOME DEUTERIUM DERIVATIVES
Authors: Gray A. P.
Published: May 2006

The vapor phase infrared spectra to 300 cm−1 are discussed and assignments made for the compounds (CH3)6Al2, (CD3)6Al2, (CH3)4Al2Cl2, (CD3)4Al2Cl2, (CH3)2Al2Cl4, CH3TiCl3, CD3TiCl3, and (CH3)2TiCl2. The assignments differ significantly from those previously published, but are consistent throughout the series of aluminum compounds and with related spectra. The data are in agreement with a bridged structure for trimethyl aluminum of D2h or C2h symmetry and with a bridged structure of dimethyl aluminum chloride with chlorine bridging. The dimer (CH3)2Al2Cl4 is shown to exist in the trans configuration. Evidence is presented indicating that an impurity is commonly found in spectra of dimethyl aluminum chloride which is identified as the mixed dimer (CH3)3Al2Cl3, aluminum sesquichloride. A number of anomalies observed in the spectra of the methyl titanium compounds are pointed out and discussed.
THE PYROLYSIS OF TRIMETHYL GALLIUM
Authors: Jacko M. G. , Price S. J. W.
Published: May 2006

The pyrolysis of trimethyl gallium has been studied in a toluene carrier flow system from 686° K to 983° K using total pressures from 6.1 mm to 31.1 mm. The progress of the reaction was followed by measuring the amount of methane, ethane, and ethylene formed. The rate constants decline rapidly if the toluene-to-alkyl ratio is decreased below 45. Part of this decrease has been shown to result from the loss of methyl radicals as ethylbenzene, propane, propylene, and xylenes. In an unseasoned vessel, the decomposition is markedly dependent on surface conditions. In the unpacked conditioned vessel, the reaction is 94% homogeneous in the first bond region and 97% homogeneous in the second bond region.The decomposition occurs in two steps:[Formula: see text]The analysis of a black solid from the reaction zone is consistent with the formation of (GaCH3)n. Both rate constants depend on the total pressure in the system, the dependence of k1 being very slight. A least-squares analysis of the experimental results gives:[Formula: see text]
THE REACTION OF ATOMIC HYDROGEN WITH FORMAMIDE VAPOR
Authors: Jamieson J. W. S.
Published: May 2006

Hydrogen cyanide was the main product of the reaction of hydrogen atoms with formamide vapor; its rate of production was fairly rapid and completely independent of reaction temperature over a wide range. If a hydrogen is abstracted from formamide it must be one of the hydrogens bonded to nitrogen. The results of this investigation suggest the possibility of another free radical chain mechanism, which does not involve hydrogen atoms, for the thermal decomposition of formamide vapor.
A TISSUE-EQUIVALENT CHEMICAL DOSIMETER SENSITIVE TO 1 RAD
Authors: Armstrong W. A. , Facey R. A. , Grant D. W. , Humphreys W. G.
Published: May 2006

The system 10−4 M terephthalic acid in 4 × 10−4 M NaOH is capable of measuring doses of ionizing radiation as low as 500 millirads. The concentration of hydroxyterephthalic acid, determined spectrophotofluorometrically, increases linearly with dose to at least 1000 rads and is independent of dose rate from 0.5 to 1000 rad/min. The energy dependence and stability of the system are also reported.
POLYMÉRISATION PAR LES RAYONS-X DU CHLORURE DE VINYLE À L'ÉTAT DE VAPEUR
Authors: Herman Jan A. , Hupin Pierre M.
Published: May 2006

The polymerization of vinyl chloride in the gas phase by X rays gives a solid polymer of 1140 average molecular weight. The G value of monomer disappearance varies from 100 to 400 and depends on pressure and temperature. From the measure of the rate of polymerization it was possible to deduce the activation energy of the chain propagation steps: 2.5 kcal/mole, and that of the hindered termination process: 7.4 kcal/mole. The negative temperature co-efficient of the polymerization is explained by the importance of this hindered termination process.
SYNTHESIS OF DEUTERATED CHLOROSILANE AND BROMOSILANE
Authors: Verma R. D. , Leitch L. C.
Published: May 2006

not available
THE USE OF ENZYMES IN STRUCTURAL STUDIES ON POLYSACCHARIDES: I. THE MODE OF ATTACK OF A β-D-(l → 3)-GLUCANASE ON LAMINARIN
Authors: Nelson T. E. , Scaletti J. V. , Smith F. , Kirkwood S.
Published: May 2006

A β-D-(1 → 3)-glucanase from the Basidiomycete sp. QM 806 of Reese and Mandels has been purified and shown to hydrolyze insoluble laminarin by removing glucose residues one at a time from the non-reducing end of the polysaccharide. The enzyme will also hydrolyze simple oligosaccharides and its mode of attack on these is similar to its action on laminarin. The products produced by the action of this preparation on laminarin are consistent with recent information on the structure of this polysaccharide.
THE ANODIC OXIDATION OF AMMONIA AT PLATINUM BLACK ELECTRODES IN AQUEOUS KOH ELECTROLYTE
Authors: Oswin H. G. , Salomon M.
Published: May 2006

Electrochemical kinetic studies are reported on the anodic oxidation of ammonia in aqueous potassium hydroxide solutions at platinum black electrodes. A kinetic scheme of consecutive reactions is proposed; Tafel slopes are deduced for various rate-determining mechanisms and compared with the experimental behavior. The reaction pathway is correlated with that involved in the analogous catalyzed ammonia vapor decomposition. The exchange currents obtained, compared with those for hydrogen oxidation, render the system unfavorable for fuel cell applications.
SYNTHESIS OF SOME PEPTIDES OF ε-N-ACETYL-L-LYSINE
Authors: Benoiton Leo
Published: May 2006

ε-N-Acetyl-L-lysinamide, α-N-glycyl-ε-N-acetyl-L-lysine, ε-N-acetyl-L-lysylglycine, α-N-glycyl-ε-N-acetyl-L-lysylglycine, and ε-N-acetylglycyl-L-lysine have been synthesized for testing as substrates for the enzyme ε-lysine acylase.
COLUMN AND GAS CHROMATOGRAPHIC ANALYSIS OF OIL OF WILD GINGER: IDENTIFICATION AND ESTIMATION OF SOME NEW CONSTITUENTS
Authors: Nigam Ishwar C. , Levi Leo
Published: May 2006

Oil of wild ginger was found to contain the following as yet unreported constituents: β-pinene, Δ3-carene, β-caryophyllene, ar-curcumene, linalool, borneol, and α-terpineol. The presence of three ketones, one of them readily generated during gas chromatographic analysis from a non-ketonic sesquiterpenoid, was also demonstrated. Formation of a sesquiterpene alcohol as a compositional artefact of the oil occurred during column chromatography over alumina.
THE INHIBITED AUTOXIDATION OF STYRENE: PART II. THE RELATIVE INHIBITING EFFICIENCIES OF META- AND PARA-SUBSTITUTED PHENOLS
Authors: Howard J. A. , Ingold K. U.
Published: May 2006

The relative rates of reaction of 11 meta- and para-substituted phenols with styrylperoxy radicals have been measured at 65 °C and have been shown to give an excellent correlation with electrophilic substituent constants. The reaction is compared with a number of similar hydrogen abstraction reactions.
DEVIATIONS FROM THE "MIXTURE LAW" IN THE RADIOLYSIS OF HYDROCARBON MIXTURES: II. YIELDS OF LIQUID PRODUCTS IN MIXTURES OF CYCLOHEXANE AND CYCLOPENTANE
Authors: Dyne P. J. , Denhartog J.
Published: May 2006

The radiolytic yields of olefins and dimers have been measured in mixtures of cyclohexane and cyclopentane. While the dimeric products ((C6H11)2, C6H11·C5H9) show a bias towards C5 groups, the olefins show a bias towards C6 groups; the yield of cyclohexene at low concentrations of cyclohexane is more than twice the maximum predicted by the "mixture law". These results confirm earlier isotopic work which showed a higher reactivity of cyclohexane-d12 in cyclohexane-d12 – cyclopentane mixtures relative to that in cyclohexane-d12 – cyclohexane. The results also confirm the preferential change of identity of cyclohexyl radicals to cyclopentyl radicals, which leads to a predominance of C5 groups in the dimer.
PREPARATION, THIN LAYER CHROMATOGRAPHY, AND ULTRAVIOLET SPECTRA OF SOME O-BENZYL DERIVATIVES OF D-GLUCOSE
Authors: Tate M. E. , Bishop C. T.
Published: May 2006

A new method for benzylation of carbohydrates has been developed which facilitated complete substitution of hydroxyl groups in one of the compounds prepared. Thin layer chromatography provides a good criterion of purity and is also a preparative method for separation of identifiable amounts of O-benzyl derivatives of carbohydrates. The number of benzyl groups in a compound can be determined by ultraviolet absorption spectroscopy. The following compounds were prepared, some of which have not been reported previously: benzyl-2,3,4,6-tetra-O-benzyl-α-D-glucoside; benzyl 2,3,4,6-tetra-O-benzyl-β-D-glucoside; methyl 2,3,4,6-tetra-O-benzyl-α-D-glucoside; 2,3,4,6-tetra-O-benzyl-α-D-glucose; l-O-(p-nitro-benzoyl)-2,3,4,6-tetra-O-benzyl-α-D-glucose; octa-O-benzyl sucrose; 3,5-di-O-benzyl-1,2-O-cyclohexylidene-α-D-xylose.
BEHAVIOR OF THE HETERO-RING IN γ-PHENYL-Δβ,γ-BUTENOLIDE DERIVATIVES TOWARD HYDRAZINES. ACID REARRANGEMENT OF 4-PHENYLAZO-2-PHENYLOXAZOLIN-5-ONE
Authors: Mustafa Ahmed , Khattab Samir A. , Asker Wafia
Published: May 2006

The substituted pyridazinones 3-phenyl- and l,3-diphenyl-5-benzylidene-1,4,5,6-tetra-hydropyridazinone-6 have been prepared from α-phenacylcinnamic acid hydrazide and α-phenacylcinnamic acid phenylhydrazone, respectively. The dipyridazinone 5,5-di(3-phenyl-1,4,5,6-tetrahydro)pyridazinone-6 was prepared from the dilactone IV, isolated as a side product in the synthesis of lactone VI.Rearrangement of 4-phenylazo-2-phenyloxazolin-5-one now has been found to proceed also in the presence of acidic reagents.
THE RATIO OF THE INDEPENDENT FORMATION CROSS SECTIONS OF THE ISOMERIC STATES OF Cs134 IN THE PROTON-INDUCED FISSION OF URANIUM
Authors: Davies J. H. , Yaffe L.
Published: May 2006

not available
OCCURRENCE OF trans-9-trans-12-OCTADECADIENOIC ACID AS A SEED OIL COMPONENT
Authors: Chisholm Mary J. , Hopkins C. Y.
Published: May 2006

trans-9-trans-12-Octadecadienoic acid was found to be a component of the glyceride oil of the seeds of Chilopsis linearis (Cav.) Sweet. It was isolated by fractional crystallization of the acids at low temperatures and removal of conjugated acids as their adducts with maleic anhydride. Identification was made by absorption spectra and by preparation of derivatives and degradative products. The acid is estimated to constitute about 15% of the total fatty acids of the oil. Linoleic acid was also identified.
SYNTHESIS OFL-ARABINOSE-5-C14
Authors: Hulyalkar R. K. , Jones J. K. N.
Published: May 2006

L-Arabinose-5-C14was synthesized by the following route: D-xylose → D-gulono-1,4-lactone-1-C14 → 2,3:5,6-di-O-isopropylidene-D-gulono-1,4-lactone-1-C14 → 2,3-O-isopropylidene-D-gulono-1,4-lactone-1-C14 → 3,4-O-isopropylidene-2,5-L-arabino-urono-lactone-5-C14 → methyl-α,β-L-arabinofuranosido-methyl uronate-5-C14 → methyl-α,β-L-arabinofuranoside-5-C14 → L-arabinopyranose-5-C14. The overall radiochemical yield of L-arabinose-5-C14was about 14% based on KC14N used in the first step. The structures of the isopropylidene derivatives of D-gulono-lactone have been clarified.
THE BUTYLLITHIUM-INITIATED POLYMERIZATION OF METHYL METHACRYLATE: PART II. MOLECULAR WEIGHT DISTRIBUTIONS
Authors: Cottam B. J. , Wiles D. M. , Bywater S.
Published: May 2006

Samples of poly (methyl methacrylate) have been made in toluene solution at −30° C with n-butyllithium initiator. Different monomer and initiator concentrations were used to obtain products of different overall molecular weights; polymerization times were varied to achieve partial as well as complete polymerization. The polymer samples were divided into fractions which were examined as to molecular weight and microstructure. It was found that the whole polymers have unusually wide molecular weight distributions which can be attributed to a combination of two narrower distributions, one of which occurs at a low and the other at a higher molecular weight region. This "double peak" phenomenon was observed for polymers at lower conversions as well as for polymers representing complete conversion of monomer. Proton magnetic resonance measurements showed that the degree of isotacticity of various fractions of a whole polymer is not the same at all molecular weights.In one case a second portion of monomer was polymerized after the complete polymerization of a first portion. Comparison of the molecular weight distribution before and after the second addition of methyl methacrylate indicated that polymer chains in all molecular weight regions, above a very low minimum value, are capable of further addition of monomer.
THE THERMAL DECOMPOSITION OF TETRAMETHYLTETRAZENE AND TETRAETHYLTETRAZENE
Authors: Gowenlock B. G. , Jones P. Pritchard , Snelling D. R.
Published: May 2006

The thermal decompositions of tetramethyltetrazene (TMT) and tetraethyltetrazene (TET) have been studied using a flow system. It is shown that both the decompositions occur at, or above, the limiting pressure for unimolecularity, and Arrhenius parameters for both decompositions are obtained. The decomposition mechanism is discussed in relation to the Arrhenius parameters and theories of three-fragment decompositions. Preliminary values of some kinetic parameters for some reactions of dialkylamino radicals are presented.
THE ALKALOIDS OF EUPATORIUM MACULATUM L.
Authors: Tsuda Y. , Marion Léo
Published: May 2006

The root of Eupatorium maculatum L. has been examined and found to contain at least four alkaloids. The major base was found to be echinatine, while the second one in importance has been identified as the non-esterified trachelanthamidine. The remaining two alkaloids are probably also of the pyrrolizidine type, but their structures could not be determined due to paucity of material.
PHENYLLITHIUM–PYRIDINE ADDUCT AS A REDUCING AGENT FOR KETONES
Authors: Abramovitch R. A. , Vig B.
Published: May 2006

The reduction of ketones to the corresponding alcohols using 1,2-dihydro-2-phenylpyridyllithium has been studied. Benzophenone is reduced more readily than is acetophenone, which in turn is more readily reduced than cyclohexanone. It is suggested that the by-product formed in the reduction of benzophenone is 4-diphenylhydroxymethyl-2-phenylpyridine.
CATALYTIC HYDRODESULPHURIZATION OF THIOPHENE: IV. THE METHYLTHIOPHENES
Authors: Desikan P. , Amberg C. H.
Published: May 2006

The hydrodesulphurization of 2- and 3-methylthiophene was studied over a sulphided, alumina-supported cobalt molybdate catalyst in a microreactor permitting the use of both pulse and steady-state flow techniques. The higher rates obtained with the 3-isomer were interpreted in terms of involvement of the α-carbon. The results were found to conform to the predominant reaction sequence proposed earlier for thiophene: C—S bond fission followed by diene and monoolefin formation and complete saturation. Some ancillary experiments on the hydrogenation of C5-olefins were reported.
KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: II. THE REACTION INHIBITED BY NITRIC OXIDE AND PROPYLENE
Authors: McKenney D. J. , Wojciechowski B. W. , Laidler K. J.
Published: May 2006

The thermal decomposition of dimethyl ether, inhibited by nitric oxide and by propylene, was studied in the temperature range of 500 to 600 °C. About 1.5 mm of nitric oxide gave maximal inhibition, the rate then being approximately 8% of the uninhibited rate. With propylene, approximately 70 mm gave maximal inhibition, the rate being slightly higher than that using nitric oxide (~12.5% of the uninhibited rate). In both cases the degree of inhibition was independent of the ether pressure. In the maximally inhibited regions both reactions are three-halves order with respect to ether pressure. As the pressure of nitric oxide was increased beyond 10–15 mm, the overall rate increased, and in this region the reaction is first order with respect to both nitric oxide and ether. A 50:50 mixture of CH3OCH3 and CD3OCD3, with enough NO to ensure maximum inhibition, was pyrolyzed. Even at very low percentage decomposition the CD3H/CD4 ratio was approximately the same as that in the uninhibited decomposition, proving that the inhibited reaction is largely a chain process. Detailed inhibition mechanisms are proposed in which the inhibitor is involved both in initiation and termination reactions.
KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: III. THE REACTION ACCELERATED BY HYDROGEN SULPHIDE
Authors: McKenney D. J. , Laidler K. J.
Published: May 2006

The thermal decomposition of dimethyl ether in the presence of hydrogen sulphide was studied in the temperature range of 480 to 530 °C, and over the pressure range of 5 to 500 mm of Hg. For a given pressure of dimethyl ether the rate of decomposition increased with the addition of increasing quantities of hydrogen sulphide, reaching a plateau after approximately 30% H2S had been added. The relative rate of decomposition then remained constant until more than 50% H2S had been added. Further increase in the hydrogen sulphide concentration produced a linear increase in the relative rate. In the region between 30 and 50% added H2S, the decomposition of dimethyl ether was three-halves order with respect to ether pressure, and zero order with respect to hydrogen sulphide pressure. In this region the three-halves-order rate constant can be expressed by k = 1.06 × 1014e−53,200/RT cc1/2 mole−1/2 sec−1. In the region beyond 50% added H2S, the reaction was first order with respect to dimethyl ether, and one-half order with respect to hydrogen sulphide. In this region the three-halves-order rate constant is given by k = 4.98 × 1014e−52,500/RT cc1/2 mole−1/2 sec−1. The experimental facts are shown to be consistent with a mechanism involving hydrosulphide radicals as the principal chain carriers. These HS radicals are produced mainly from the reaction of methyl radicals with hydrogen sulphide. The work leads to a value of 85.6 kcal for the dissociation energy of H2S into H + SH.
THE METAL-CATALYZED AUTOXIDATION OF TETRALIN: I. INTRODUCTION. THE COBALT-CATALYZED AUTOXIDATION IN ACETIC ACID
Authors: Kamiya Y. , Beaton S. , Lafortune A. , Ingold K. U.
Published: May 2006

The catalytic effect of transition metal salts on the rate of autoxidation of organic substances reaches a constant value at some critical catalyst concentration. Three possible explanations of this phenomena are critically examined. The cobalt acetate catalyzed autoxidation of tetralin in acetic acid has been reinvestigated and the limiting rate of oxidation at high cobalt concentrations has been shown to be due to the production of a steady-state concentration of hydroperoxide. The present results are in fair agreement with the experimental work of Woodward and Mesrobian (J. Am. Chem. Soc. 75, 6189 (1953)) and are in excellent agreement with theoretical predictions.
ACID-CATALYZED REACTIONS OF VINYL COMPOUNDS: PART II. PRODUCTS OF THE REACTION OF VINYL ACETATE AND BENZENE
Authors: Pepper J. M. , Robinson B. P.
Published: May 2006

not available
COORDINATION COMPLEXES OF GROUP (IV) HALIDES: PREPARATION AND INFRARED SPECTRA OF COORDINATION COMPOUNDS OF TITANIUM TETRACHLORIDE, TITANIUM TETRABROMIDE, ZIRCONIUM TETRACHLORIDE, AND TIN TETRACHLORIDE WITH α,ω-DINITRILES AS LIGANDS
Authors: Jain Sumer Chand , Rivest Roland
Published: May 2006

Coordination complexes between dinitriles of dicarboxylic acids and tetrahalides of titanium, zirconium, or tin have been prepared. The analytical results and the infrared spectra indicate that on working under different experimental conditions three types of compounds are obtained: 2MX4.L—L, MX4.L—L, and MX4.2L—L where MX4 is a Lewis acid and L—L a bidentate ligand. The compounds 2MX4.L—L are explained by the formation of halogen bridging between the two metal atoms. The compounds MX4.L—L are considered to be either coordination polymers or chelates of variable ring size and the compounds MX4.2L—L, ordinary addition compounds where no chelation takes place because of the mutual interaction of the two CN groups in a dinitrile of a short chain length.
THE HEARTWOOD EXTRACTIVES OF PINUS BANKSIANA LAMB
Authors: Rudloff E. von , Sato A.
Published: May 2006

The heartwood of jack pine was analyzed by various chromatographic techniques and countercurrent distribution. The major components were found to be isopimaric, abietic, dehydroabietic, and neoabietic acids, as well as glycerides of oleic, linoleic, and linolenic acids. Smaller amounts of pimaric, sandaracopimaric, myristic, palmitic, stearic, palmitoleic, and four unidentified acids were recorded, as well as fatty acid esters of β-sitosterol, α-terpineol, and four unidentified volatile alcohols. Of the phenols, pinocembrin, pinobanksin, and pinosylvin monomethyl ether predominated. Pinosylvin was isolated and several minor constituents including lignan-like compounds were detected in the acetone extract. The methanol extract was composed mainly of polymeric lignan-like fractions. From one of these a trimer, C60H66O24, m.p. 186–188 °C, αd + 3.2°, was isolated. The small amount of steam-volatile material consisted mainly of α- and β-pinene, benzoic acid, and α-terpineol. Traces of methyl benzoate, camphene, limonene, β-phellandrene, cis-p-menthan-8-ol, and nine unidentified trace components were recorded.
ISOTOPE EFFECTS IN X-RAY-IRRADIATED ACIDIFIED H2O–D2O SOLUTIONS
Authors: Lifshitz Chava
Published: May 2006

H2O–D2O mixtures containing 0.1–1 N H2SO4 were irradiated by 200-kv X rays. The molecular isotope effect, [Formula: see text], was determined from experiments on KBr solutions. The atomic isotope effect, [Formula: see text], was determined from experiments on ethanol solutions. At 96% D2O, αA = 3.7 ± 0.5 and αM = 4.0 ± 0.2. The isotope effects are discussed in connection with the radiation-chemical reaction H3O+ + eH2O → H + 2H2O. The connection between the atomic and molecular hydrogen is discussed. It is concluded that the relation between the observed atomic and molecular isotope effects is not contrary to a hydrogen atom recombination reaction leading to the molecular product. Isotope effects due to the oxidation of Fe+2 ions by hydrogen atoms in acid solutions were measured and the mechanism of this reaction is discussed.
INTERACTION OF VANADIUM WITH PROTONS OF ENERGIES UP TO 84 MEV
Authors: Hontzeas S. , Yaffe L.
Published: May 2006

Radiochemical techniques have been used to determine absolute excitation functions for 17 nuclides formed as spallation products from the irradiation of vanadium by protons of energy up to 84 Mev. The shape of the excitation functions and classical threshold calculations showed evidence of contribution of heavy-particle emission in the reactions of the type (p,3pxn), (p,5pxn), and (p,7pxn). The Barr method for analysis of the cross-section distribution was modified and applied at 60 and 80 Mev bombarding energies. The experimentally measured cross sections for 16 nuclides at 60 and 80 Mev bombarding energies were fitted to the four-parameter Rudstam equation σ (A,Z) = exp [PA−Q−R(Z−SA)2]. Comparison of the results obtained at 8 Mev bombarding energy with the predictions of the weak and strong absorption models showed better agreement with the predictions obtained by using the surface absorption Fernbach–Bjorklund potential.
A SYNTHESIS OF 3,3,3-TRICHLORO-1,2-EPOXYPROPANE FROM THE TETRAHALOPROPANE DERIVED FROM A CARBON TETRAHALIDE AND ETHYLENE
Authors: Reeve Wilkins , Fine Leonard W.
Published: May 2006

A study has been made of the reactions involving the addition of bromotrichloromethane to ethylene to give 3-bromo-1,1,1-trichloropropane, subsequent dehydrohalogenation of this to 3,3,3-trichloro-1-propene, and the isomerization of the latter to 1,1,3-trichloro-1-propene; the experimental conditions have been improved so that the minimum yield obtained in any one step is 78%. The 1,1,3-trichloro-1-propene is converted to a chlorohydrin in 36% yield by reaction with tert-butyl hypochlorite, and the chlorohydrin is converted in 61% yield to 3,3,3-trichloro-1,2-epoxypropane by treatment with base. The reaction of 3,3,3-trichloro-1-propene with methoxide ion to form 1,1-dichloro-3-methoxy-1-propene provides another example of an SN2′ reaction.
INTERBRANCH SEQUENCES IN THE WHEAT ARABINO-XYLAN: SELECTIVE ENZYMOLYSIS STUDIES
Authors: Goldschmid H. R. , Perlin A. S.
Published: May 2006

A Streptomyces xylanase degrades the soluble arabino-xylan of wheat with formation of polymeric fragments and several oligosaccharides. The overall data, together with information about the spatial requirements of the xylanase, show that (a) the arabino-xylan molecules are constituted predominantly of highly branched regions in which isolated and paired L-arabinosyl branches are separated by single D-xylosyl units; (b) at unequal intervals (averaging 20−25 main-chain units) this type of sequence is interrupted by "open regions" of at least two to five unbranched D-xylosyl units; and (c) infrequently, an L-arabinosyl branch is removed from other branches at either side by at least two D-xylosyl units.A new tetrasaccharide isolated from the enzymic digest is shown to be O-α-L-arabino-furanosyl-(1 → 3)-O-[β-D-xylopyranosyl-(1 → 4)]-O-β-D-xylopyranosyl-(1 → 4)-D-xylose.
THE SYNTHESIS OF ALKYLPHOSPHONOUS DICHLORIDES FROM ALUMINUM CHLORIDE – PHOSPHORUS TRICHLORIDE – ALKYL CHLORIDE COMPLEXES
Authors: Perry B. J. , Reesor J. B. , Ferron J. L.
Published: May 2006

In 1957, a new method for the synthesis of methylphosphonous dichloride, in high yield, by the reduction of the aluminum chloride – phosphorus trichloride – methyl chloride complex in diethyl phthalate solution by finely powdered antimony, was developed. That this is a general method for the synthesis of the more volatile alkylphosphonous dichlorides was demonstrated by the preparation, in good yield, of a series of compounds from the aluminum chloride – phosphorus trichloride complexes formed from ethyl chloride, n-propyl chloride, i-propyl chloride, n-butyl chloride, and s-butyl chloride. As expected, isomerization occurred in the case of the normal alkyl chlorides.
THE FORCES OPERATIVE IN HOMONUCLEAR DIATOMIC MOLECULES
Authors: Bader Richard F. W.
Published: May 2006

The electron densities obtained from the S.C.F. wave functions determined by Ransil for some first-row homonuclear diatomic molecules are tested through a calculation of the forces acting on the nuclei. None of the density functions (for Li2, Be2, C2, N2, and F2) give the required condition of electrostatic equilibrium, the departure from a nonzero force increasing with increasing nuclear charge. Adverse atomic polarizations are shown to be primarily responsible for these results, and in particular for the surprising result that the density in the 3σg orbital of N2 and F2 actually exerts a force tending to separate the molecule into atoms.
CONSTITUTION OF THE HEMICELLULOSE FROM MESTA FIBER (HIBISCUS CANNABINUS)
Authors: Sen S. K.
Published: May 2006

The chlorite holocellulose of mesta fiber (Hibiscus cannabinus) was extracted with alkaline solutions of successively increasing concentration and finally with alkaline borate solution. Hemicellulose fractions (I–IV) were thus obtained. Analytical data are recorded for each fraction.Partial acid hydrolysis of the mesta hemicellulose gave 2-O-(4-O-methyl-α-D-glucopyranosyl uronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated hemicellulose (fraction II) gave a mixture of 3-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyl uronic acid)-3-O-methyl-D-xylopyranose in the approximate molar ratio of 1.6:34:1:6.4. The number-average molecular weight of the methylated polysaccharide was 18,400 ± 500 (degree of polymerization, 110 ± 3). The number-average molecular weight of the original hemicellulose (fraction II) was found to be 23,000 ± 500 (degree of polymerization, 164 ± 3). On the basis of this and other evidences it is suggested that the polysaccharide is composed of chains of 144 (1 → 4)-linked β-D-xylopyranose residues having approximately every seventh residue carrying a terminal 4-O-methyl-α-D-glucuronic acid residue linked through position 2. A small degree of branching in the backbone of D-xylose is indicated.
THE OXIDATION OF FERROUS SULPHATE BY Co60 γ-RADIATION
Authors: Onat E. , Haines R. L. , Henderson I. H. S.
Published: May 2006

An investigation of the Co60 γ-oxidation of ferrous sulphate in the range 0.015 to 0.15 M in 1.0 N, 5.0 N, and 10.0 N sulphuric acid solutions shows that although the yields obtained were invariably higher than those predicted from the concentration ratios of ferrous ion to dissolved oxygen, no evidence was obtained to confirm the very high yields reported by Proskurnin and co-workers. The increase in yield observed has been attributed to interference with the "primary" hydrogen yield by a mechanism involving electron or hydrogen atom capture by a ferrous ion – oxygen complex.
SYNTHESES INVOLVING IMIDOGEN INTERMEDIATES: PHENANTHRIDINES AND BENZO[c]PHENANTHRIDINES
Authors: Abramovitch R. A. , Newman D. , Tertzakian G.
Published: May 2006

not available
THE REACTION OF METHYL RADICALS WITH METHYL ALCOHOL
Authors: Shannon T. W. , Harrison A. G.
Published: May 2006

The photolysis of acetone in the presence of methyl alcohol and of methyl-d3 alcohol has been studied between 406 and 472° K. The rates and Arrhenius parameters for the following abstraction reactions have been determined:[Formula: see text]

[Formula: see text]

[Formula: see text]At 182 °C the rate of reaction [b] is found to be approximately four times greater than the rate of reaction [c].
DINITROPHENYL PEPTIDES: I. PREPARATION AND PROPERTIES OF SOME DINITROPHENYL GLYCYL DIPEPTIDES
Authors: Loudfoot J. H. , Kruger J. E.
Published: May 2006

Some dinitrophenyl glycyl peptides have been prepared from dipeptides and from dinitrophenyl glycyl chloride, and the products suitably characterized. Electrophoresis gave good separation of those differing by more than two carbon atoms.
THE SULPHURIC ACID SOLVENT SYSTEM: PART V. SOLUTIONS OF SOME ORGANOSILICON COMPOUNDS
Authors: Flowers R. H. , Gillespie R. J. , Robinson E. A.
Published: May 2006

The cryoscopic and conductimetric behavior of solutions of hexamethyldisiloxane, trimethylethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, and tetraphenylsilane in 100% sulphuric acid has been investigated. The measurements show that stable non-electrolytes such as (CH3)3Si·HSO4 and (CH3)2Si(HSO4)2 are formed from the tri- and di-alkyl compounds. Species such as CH3Si(HSO4)3, which are presumably formed in the reaction of monoalkyl compounds, and Si(HSO4)4, which it is reasonable to suppose is the initial product from the cleavage of tetraphenylsilane, are unstable and polymerize to give polymers containing Si—O—Si bridging groups. No evidence was obtained for the formation of siliconium ions or for the formation of compounds containing silicon with a coordination number greater than four.
POLAROGRAPHY OF VANADIUM (II) COMPLEXES
Authors: Biermann Wendell J. , Wong Wen-Kuei
Published: May 2006

Polarograms taken in solutions of vanadium (II) perchlorate, 0.10 N with respect to perchloric acid and at an ionic strength of 0.20, indicate that vanadium (II) exists predominately as a dimer in the concentration region of 5 millimolar. Oxidation of one of these ions appears to make the second relatively inert towards oxidation until labilized by further oxidation of the first to vanadyl ion.No indication of complex formation of vanadium (II) was found with sulphate, chloride, iodide, or bromide ions. The existence of fluoro and thiocyanato complexes was noted, the vanadium (II) complexes having lower formation constants than the corresponding vanadium (III) complexes.
REACTIONS PRODUCED ON ERBIUM BY PROTONS OF ENERGIES BETWEEN 6 AND 87 MEV
Authors: Rayudu G. V. S. , Yaffe L.
Published: May 2006

Erbium was bombarded with protons of energies varying between 6 and 87 Mev. Nuclear characteristics and excitation functions were studied for isotopes of Tm, Er, Ho, and Dy, formed by various (p,xn) and (p,xpxn) reactions. Bombardment of enriched Er isotopes helped elucidate some of the excitation functions. A comparison has been made of the experimental (p,xn) cross sections with those predicted by the Jackson model and reasonable agreement has been found. Holmium was bombarded with α-particles to produce the compound nucleus Tm169* and the ratios σ (p,n): σ (p,2n) = σ (α,n): σ(α,2n) were found to hold.
TARTRATE COMPLEXES OF THE RARE-EARTH ELEMENTS: I. THE d-, dl-, AND meso-TARTRATE COMPLEXES OF Tb AND Eu
Authors: Manning P. G.
Published: May 2006

Solvent extraction and radiotracer techniques have been applied to the study of metal – tartrate ion association in water at 25 °C. Trace concentrations of the radioisotopes Tb160 and Eu152/154 were equilibrated between aqueous sodium tartrate solutions and organic phases of thenoyltrifluoroacetone in toluene. The ionic strength (0.0597) and the pH (4.53) of the aqueous phase were kept constant by means of sodium perchlorate and sodium acetate.Metal complexing with the d-, dl-, and meso isomers of the ligand was examined. For all isomers two complex species were identified with metal:ligand ratios of 1:1 and 1:2, and stability constants for both stages of ion association have been estimated. No third (1:3) complex was detected.Metal coordination numbers and the formation of tartrate–tartrate hydrogen bridges in the 1:2 complex are discussed.
TOXIC FLUORINE COMPOUNDS: XIX. ω-FLUOROALKYNES
Authors: Pattison F. L. M. , Dear R. E. A.
Published: May 2006

Some ω-fluoroalkynes have been prepared and shown to be valuable intermediates in the synthesis of rare long-chain ω-fluoro compounds; successful representative reactions, in all of which the C—F bond remained intact, included Grignard reactions, partial and total catalytic hydrogenation, halogenation, and miscellaneous coupling reactions.
THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: II. A GLUCAN FROM MICROSPORUM QUINCKEANUM
Authors: Alfes H. , Bishop C. T. , Blank F.
Published: May 2006

A levorotatory glucan with a minimum degree of polymerization of 36 has been isolated from the water-soluble polysaccharides of the dermatophyte Microsporum quinckeanum. Hydrolysis of the methylated glucan yielded the following O-methyl-D-glucoses: 2,3,4,6-tetra-(10.2 mole%); 2,3,4-tri- (57.7 mole%); 2,4,6-tri- (22.2 mole%); 2,4-di- (8.2 mole%); and 2-mono- (1.6 mole%). The glucan consumed 1.53 moles of periodate with production of 0.70 mole of formic acid per mole anhydroglucose. Reduction and hydrolysis of the periodate-oxidized glucan yielded glycerol, erythritol, and D-glucose in a molar ratio of 72.3:0.6:27.1. The results showed that the glucan consisted of β-D-glucopyranose units joined in straight chains by 1 → 6 (57%) and 1 → 3 (24%) linkages. Approximately 3 in every 37 glucose residues constitute branch points in the glucan with branches occurring at the C6and C3positions of the same glucose unit. The glucan bears some resemblance to the yeast glucans of Saccharomyces cerevisiae and Candida albicans but differs from them in the relative number of 1 → 6 and 1 → 3 linkages and in the degree of branching.
LYCOPODIUM ALKALOIDS XIII. MASS SPECTRA OF REPRESENTATIVE ALKALOIDS
Authors: MacLean D. B.
Published: May 2006

The mass spectra of a number of Lycopodium alkaloids are recorded and schemes proposed for their fragmentation. The loss of the bridge dominates the fragmentation process in the structural types examined.
THE REDUCTIVE CLEAVAGE OF 1,3-OXATHIOLANES WITH LITHIUM ALUMINUM HYDRIDE IN THE PRESENCE OF ALUMINUM CHLORIDE OR BORON TRIFLUORIDE
Authors: Leggetter B. E. , Brown R. K.
Published: May 2006

A number of 1,3-oxathiolanes and 1,3-dithiolanes were subjected to reduction in ether solution by lithium aluminum hydride in the presence of either aluminum chloride or boron trifluoride. Both of these Lewis acids not only isomerized 1,3-oxathiolanes but also catalyzed their hydrogenolysis to the hydroxy thioethers. Under the same conditions neither aluminum chloride nor boron trifluoride had any effect upon 1,3-dithiolanes. However, in methylene chloride solution, 1,3-dithiolanes are isomerized by both Lewis acids although their hydrogenolysis was not achieved, probably due to the insolubility of the hydride in methylene chloride.A mechanistic interpretation is discussed to explain the results obtained.
DESULPHURIZATION WITH RANEY NICKEL III. BENZYL N-ALKYL-N-BENZENESULPHONYLCARBAMATES
Authors: Pettit George R. , Kadunce Raymond E.
Published: May 2006

not available
NUCLEAR SPIN–SPIN COUPLING CONSTANTS INVOLVING THE GROUP IV ELEMENTS
Authors: Reeves L. W. , Wells E. J.
Published: May 2006

not available
MERCURY PHOTOSENSITIZED DECOMPOSITION OF LIQUID CYCLOHEXANE
Authors: Klots Cornelius E. , Johnsen R. H.
Published: May 2006

not available
THE MIXED COMPLEXES OF COPPER(II) AND NICKEL(II) WITH NITRILOTRIACETATE AND GLYCINATE AND THE FORMATION CONSTANT OF THESE AND OTHER MIXED COMPLEXES
Authors: Israéli Y. J.
Published: May 2006

not available
PYROLYSIS OF 3-HEXENEDIOIC ACID
Authors: Shulman Garson P. , Osteraas Jean
Published: May 2006

not available
THE DETERMINATION OF SELF-ASSOCIATION EQUILIBRIUM CONSTANTS BY INFRARED ABSORPTION SPECTROSCOPY
Authors: Vinogradov Serge N.
Published: May 2006

not available
THE FLASH PHOTOLYTIC REDUCTION OF 2-ACETONAPHTHONE IN SOLUTION
Authors: Bryce W. A. , Wells C. H. J.
Published: May 2006

not available
THE EFFECT OF PHENOLS AND AROMATIC THIOLS ON THE POLYMERIZATION OF METHYL METHACRYLATE
Authors: Barton S. C. , Bird R. A. , Russell K. E.
Published: May 2006

Chain transfer constants of a number of phenols in the polymerization of methyl methacrylate have been determined. They are small compared with the corresponding transfer constants with styrene, a maximum value of 0.0026 being observed with pyrogallol. Three deuterated phenols do not have a measurable effect on the rate and degree of polymerization, showing that attack takes place mainly at the O—H group.The aromatic thiols investigated have transfer constants in the range 2.6 to 7.4. They cause only slight retardation of polymerization, and efficiencies of reinitiation by aromatic thiol radicals are estimated to be at least 95%. The transfer constants of meta-substituted thiols do not differ greatly from that of benzenethiol showing that inductive effects are small. A wider range of reactivities is observed with the para-substituted thiols, indicating the existence of small but significant resonance effects.
THE TRANSMISSION OF POLAR EFFECTS
Authors: Bowden Keith
Published: May 2006

The transmission of polar effects by various groups is assessed by means of the reaction constants ρ or ρ″. The results are critically discussed in terms of the various polar, steric, and solvent effects. Conclusions are drawn as to the importance of the inductive and direct field effects.
THE RELATIVE ACCEPTOR POWER OF BORON TRIHALIDES AND BORANE TOWARD TRIMETHYLAMINE
Authors: Miller J. M. , Onyszchuk M.
Published: May 2006

Gas phase displacement reactions of boron trihalides from their trimethylamine adducts show that the order of acceptor power is: BBr3 > BCl3 > BF3 > 1/2(B2H6). This order agrees with recent theoretical calculations and dipole moment, calorimetric, and infrared measurements on boron trihalide complexes with other reference bases.
TERPENOIDS: IV. THE STRUCTURE AND STEREOCHEMISTRY OF HELMINTHOSPORAL
Authors: Mayo P. De , Spencer E. Y. , White Robert W.
Published: May 2006

Helminthosporal has been converted into the anhydride (X), which has been dehydrogenated to give (VI): this compound has been synthesized. Spectroscopic study of a number of derivatives of helminthosporal has enabled a decision to be made in favor of (XXVI; R = CHO) as a representation of the structure and stereochemistry of the dialdehyde.
N.M.R. SPECTRA OF TIN COMPOUNDS: I. H1 AND F19 MAGNETIC RESONANCE SPECTRA OF DIMETHYL-1,1,2,2-TETRAFLUOROETHYLTIN HYDRIDE, DIMETHYLBIS(1,1,2,2-TETRAFLUOROETHYL)TIN, AND DIMETHYLTIN DIHYDRIDE
Authors: Clark H. C. , Kwon J. T. , Reeves L. W. , Wells E. J.
Published: May 2006

The H1 and F19 magnetic resonance spectra of three tin compounds have been examined. Taking advantage of C13, Sn117, and Sn119 being magnetic nuclei in small natural abundance, it has been possible to obtain 31 coupling constants from the spectra.
QUADRUPOLE RELAXATION FOR A SPIN I = 3/2: THE F19 N.M.R. SPECTRA OF BF3 AND ClO3F
Authors: Bacon J. , Gillespie R. J. , Quail J. W.
Published: May 2006

An expression is derived for the broadening of the components of the quartet obtained for the n.m.r. spectrum of nuclei coupled to a nucleus of spin 3/2 undergoing electric quadrupole relaxation. It is shown that the F19 spectra of BF3 and ClO3F at various temperatures may be satisfactorily interpreted by means of this expression. Activation energies for molecular reorientation of 1.4 kcal/mole for BF3 and 1.0 kcal/mole for ClO3F are obtained.
TETRAHYDROFURANS: II. SPIRO COMPOUNDS CONTAINING THE TETRAHYDROFURAN RING
Authors: Wasson B. K. , Kernan J. A. , Parker J. M.
Published: May 2006

2-Allyl-2-methallyl-1,3-propanediol (IV) and 2,2-dimethallyl-1,3-propanediol (V) were cyclized in the presence of mineral acid to give 3,3,8-trimethyl-2,7-dioxaspiro(4.4)nonane (VIII) and 3,3,8,8-tetramethyl-2,7-dioxaspiro(4.4)nonane (IX), respectively. Similarly, 2-methallyl-2-(3-methyl-2-butenyl)-1,3-propanediol (VI) afforded 3,3,8,8-tetramethyl-2,7-dioxaspiro(4.5)decane (X). The diol VI was derived from diethyl methallylmalonate by condensation with 3-methyl-2-butenyl bromide, followed by reduction of diethyl methallyl(3-methyl-2-butenyl)malonate (III) with lithium aluminum hydride. The assigned structures of the spiro compounds were supported by infrared and nuclear magnetic resonance spectral analyses.
LYCOPODIUM ALKALOIDS: PART VIII. NEW ALKALOIDS FROM JAMAICAN LYCOPODIUM SPECIES
Authors: Burnell R. H. , Chin C. G. , Mootoo B. S. , Taylor D. R.
Published: May 2006

Four more alkaloids have been isolated from Lycopodium fawcettii. Lycodine and des-N-methyl-α-obscurine have been found in other Lycopodium species but base L, C18H31NO4, and base R, C16H24N2O2, are new. Some transformations of base L are described including its conversion to the previously described base O. An unstable base from L. clavatum has been characterized as the picrate C15H25NO3.C6H3N3O7. Further characterization of the two bases fawcettidine (base F) and fawcettimine (base A) is reported.
ENERGETICS AND MECHANISM OF HYDRONIUM ION FORMATION BY ELECTRON IMPACT
Authors: Raalte D. Van , Harrison A. G.
Published: May 2006

The reactions leading to formation of the hydronium ion in the mass spectra of a number of alcohols and formate esters have been elucidated through a study of appearance potentials and metastable transitions and by the use of deuterium labelling. The results lead to ΔHf(H3O+) = 157 ± 3 kcal/mole corresponding to a proton affinity of the gaseous water molecule of 151 ± 3 kcal/mole.
TRITIUM RECOIL LABELLING OF LITHIUM ALUMINUM HYDRIDE
Authors: Măntescu Constanţa , Genunche Ana
Published: May 2006

not available
THE REACTION OF HYDROGEN ATOMS WITH KETENE
Authors: Demchuk Nick , Gesser H.
Published: May 2006

The gas-phase reaction of atomic hydrogen with ketene has been investigated over a temperature range of −130° to 232 °C using a low-pressure, fast-flow system. In most cases methane, carbon monoxide, and ethane were the major products, but trace amounts of glyoxal were also detected. Above −96 °C. considerable evidence exists for the occurrence of a chain reaction carried by HCO radicals. The surface reaction at −196 °C produced methane and glyoxal predominantly with only a minor amount of carbon monoxide.
CONTRIBUTION TO THE INFRARED SPECTRA OF FIVE-MEMBERED N- AND N,S-HETEROCYCLIC COMPOUNDS
Authors: Rao C. N. R. , Venkataraghavan R.
Published: May 2006

Infrared spectra of 5-membered N- and N,S-heterocyclic derivatives such as triazoles, tetrazoles, thiazoles, thiadiazoles, thiatriazoles, and dithiazoles have been examined and empirical assignments have been made. The spectra of the two dithiazolidine derivatives, isoperthiocyanic acid and oxidation product of dithiobiuret, have been studied in detail. Assignments for benzthiazole derivatives are reported. The CH out-of-plane deformation bands of benzene rings fused to five-membered heterocyclic rings have been found to be in the region 760–740 cm−1, characteristic of four adjacent benzenoid hydrogen atoms.
PHOTOCHEMICAL TRANSFORMATIONS OF DIENES: I. THE PHOTOLYSIS OF 3-ALKOXYCHOLESTA-3,5-DIENES
Authors: Just George , Leznoff Clifford C.
Published: May 2006

The photolysis of 3-alkoxycholesta-3,5-dienes in an alcohol has been found to result in a stereospecific addition of the alcohol to the Δ3 double bond with formation of β,γ-unsaturated ketals. On silica gel, the non-cyclic β,γ-unsaturated ketals gave cholest-5-en-3-one.