The location of olefinic bonds in mono- and di-unsaturated compounds

The use of vinyl methyl ether as a chemical ionization reagent gas for the location of olefinic bonds is limited by reactions of various ion with vinyl methyl ether molecules. A 75: 20: 5 mixture of nitrogen/carbon disulphide/vinyl methyl ether suggested by Harrison and Chai gives much cleaner spectra and has been used to study octenes and octadienes. Evidence is presented to indicate the formation of two reaction complexes with octenes and four reaction complexes with unconjugated octadienes. Elimination of olefins from these complexes allows one to infer the positions of the carbon-carbon double bonds in each type of molecule.     

The reaction of methylborylene with cyclohexene and some other olefinic compounds

Some potential methylborylene-generating systems were investigated, using cyclohexene as the trapping agent. Methylborylene, generated by the system 2C₈K/MeBBr₂, reacts with cyclohexene to yield 2-methyl-2-boratricyclo-[7.4.0.0^3.8]-tridecane (MBTT) Ia. In the course of the work an isomer of MBTT was synthesized along a completely different route and compared with Ia. With the system 2C₈K/MeBBr₂, only cyclic olefins were converted to analogues of MBTT. An acyclic olefin and a conjugated diene yielded only haloboration products. Possible mechanisms leading to the formation of MBTT Ia are discussed.     

Catalytic addition of trihalogenomethanesulfenyl chlorides to olefinic compounds

Trifluoroacetic acid has been found to be an efficient catalyst for the addition of fluorochloromethanesulfenyl chlorides CF_nCl_3?nSCl (n = 1, 2, 3) to olefins such as cyclohexene, 1-hexene, allyl bromide and vinyl bromide. The reaction with cyclohexene led to trans adducts. The addition to asymmetrical olefins afforded a mixture of Markovnikov- and anti-Markovnikov oriented adducts. The factors influencing the reaction course are discussed.     

Free radicals in γ-irradiated olefinic silica compounds

Results are reported from -irradiation of compounds of structure . each of which gives a characteristic ESR spectrum having a hyperfine structure whose resolution is somewhat reduced by the coupling of the radical to the silica. The splittings are 23–25 Oe (typical of alkyl radicals), except for the phenyl compound. Improved resolution is provided by varying the temperature between –196 and 20C. The bond to the surface gives the radical high thermal stability; contact with air at 20C converts the alkyl radicals to peroxyl ones. Hyperfine splitting from the hydrogen H_p 5000 Oe is observed in all compounds except.     

Stereospecific incorporation of 13CO into olefinic substituted metal carbonyl compounds

The triene complex, (bicyclo[6.1.0] nona-2,4,6-triene)molybdenum tricarbonyl, has been observed to react with ¹³CO in solution to afford stereospecifically the axially labelled ¹³CO tetracarbonyl derivative. Further reactions of this ¹³CO derivative with triphenylphosphine or bis(1,2-diphenylphosphino)ethane resulted in formation of the cis disubstituted phosphine derivatives with retention of the ¹³CO label.     

The use of ozone as a titrimetric agent for the quantitative determination of olefinic unsaturation

A new method is described for the determination of olefinic unsaturation, using a constant stream of ozone as the titrimetric agent. A dye is employed as the end-point indicator. The ozone is prepared by electrolysis of dilute sulphuric acid.The method is shown to possess a number of advantages over the methods so far in use for determining unsaturation. It may be satisfactorily applied to a wide variety of substituted as well as unsubstituted unsaturates.     

The determination of metals in organic compounds

Summary A comprehensive review of the methods available for the determination of metals in organic compounds has been made. The following metals have been considered:—sodium, potassium, lithium, rubidium, caesium, magnesium, calcium, barium, strontium, boron, thallium, silicon, germanium, antimony, bismuth, tin, lead, selenium, tellurium, silver, gold, osmium, platinum, copper, cadmium, zinc, mercury, vanadium, chromium, iron, cobalt, nickel, niobium, tantalum, rhenium, titanium, zirconium and uranium.

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Zusammenfassung Eine vollständige Übersicht über Methoden zur Bestimmung von Metallen in organischen Verbindungen wird gegeben. Für folgende Metalle werden Methoden beschrieben: Natrium, Kalium, Lithium, Rubidium, Cäsium, Magnesium, Calcium, Barium, Strontium, Bor, Thallium, Silicium, Germanium, Antimon, Wismut, Zinn, Blei, Selen, Tellur, Silber, Gold, Osmium, Platin, Kupfer, Cadmium, Zink, Quecksilber, Vanadium, Chrom, Eisen, Kobalt, Nickel, Niob, Tantal, Rhenium, Titan, Zirkonium und Uran.

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Résumé On donnait une revue complète des méthodes valables pour le dosage des métaux dans des substances organiques. Des méthodes sont décrites pour les métaux suivants: sodium, potassium, lithium, rubidium, caesium, magnésium, calcium, barium, strontium, bore, thallium, silicium, germanium, antimoine, bismuth, étain, plomb, sélénium, tellure, argent, or, osmium, platine, cuivre, cadmium, zinc, mercure, vanadium, chrome, fer, cobalt, nickel, niobe, tantale, rhenium, titane, zirconium et urane.

     

The determination of mercury in organic compounds

The micro oxygen-flask combustion technique in combination with the sodium diethyldithiocarbamate titration is a rapid and useful method for determination of mercury in organic compounds. Chlorine and bromine do not interfere; iodine does. When the organic compound contains both mercury and chlorine, the chloride ions can be titrated argentometrically in the same absorption solution after the titration of mercury.     

A kinetics study of the reactions of OH with several aromatic and olefinic compounds

The reactions of hydroxyl radicals with eight substituted aromatic hydrocarbons and four olefins were studied utilizing the flash photolysis–resonance fluorescence technique. The rate constants were measured at 298°K using either Ar or He as the diluent gas. The values of the rate constants (k × 10¹²) in the units of cm³/molec. sec are

相似文献   

Micro determination of olefinic unsaturation. Reaction of N-bromosuccinimide with olefins in polar medium

Summary A micro method for the determination of olefinic unsaturation in organic compounds has been developed. 2–10 mg sample dissolved in acetic acid is reacted with a known excess of N-bromosuccinimide at room temperature and the excess reagent is back titrated iodometrically. The maximum deviation in the results is ±2%. The compounds containing electron withdrawing groups close to the C=C site are not reactive and hence could not be determined by this procedure.

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Mikrobestimmung der Ungesättigtheit von Olefinen. Reaktion von N-Bromsuccinimid mit Olefinen in polarem Medium

Zusammenfassung 2–10mg der Probe werden in Essigsäure gelöst, mit überschüssigem Reagens versetzt und der Überschuß jodometrisch zurücktitriert. Der maximale Fehler der Ergebnisse beträgt ±2%. Verbindungen, die benachbart zur C=C-Doppelbindung elektronenentziehende Gruppen enthalten, können nicht analysiert werden.

     

The determination of oxygen in sulphur-containing organic compounds

Summary The reactions of anhydroiodic acid with CS₂, H₂S, and COS have been quantitatively investigated at 120° C and 170° C. The iodine formed was titrated and the gaseous reaction products determined by gas chromatography. At 170° C, CS₂ and COS are quantitatively oxidized to CO₂ and SO₂, and H₂S is oxidized to water and partially to SO₂ while a stoicheiometric fraction of the sulphur is obtained as elemental S. At 120° C the reactions are the same although in no case is the oxidation completely quantitative at this temperature.

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Zusammenfassung Die Reaktionen der Anhydrojodsäure mit CS₂, H₂S und COS wurden bei 120 und 170° C quantitativ untersucht. Das freigesetzte Jod wurde titriert und die gasförmigen Reaktionsprodukte gaschromatographisch bestimmt. Bei 170° C werden CS₂ und COS quantitativ zu CO₂ und SO₂ oxydiert, H₂S zu Wasser und teilweise zu SO₂, während ein stöhiometrischer Anteil des Schwefels in elementare Form übergeht. Bei 120° C laufen die gleichen Reaktionen ab, aber keinesfalls quantitativ.

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Résumé On a fait l'étude quantitative des réactions de l'acide anhydroiodique avec CS₂, H₃S et COS à 120° C et 170° C. On a titré l'iode formé et réalisé le dosage des produits gazeux de la réaction par Chromatographie en phase gazeuse. A 170° C, CS₂ et COS sont oxydés quantitativement en CO₂ et SO₂; H₂S est oxydé en eau et partiellement en SO₂ et il se forme une fraction stoechiométrique de soufre à l'état élémentaire. A 120° C, les réactions sont les mêmes bien que l'oxydation ne soit jamais quantitative à cette température.

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This work was supported by grants from the Statens Tekniska Forskningsrad (Swedish Technical Research Council).     

The thermometric and enthalpimetric determination of organic compounds

Two main parameters determine the methods for the assay of organic compounds in industrial systems; these are the rates of reaction of the molecular organic and often non-aqueous systems which differ from those in ionic and aqueous systems, and secondly, the fact that in most organic systems an organic functional group is required to be determined by a general method applicable to the functional group in a variety of chemical environments. In pharmaceutical products it is desired to determine the functional groups without prior separation from excipients of various kinds and to obtain rapid assays, often with precision much lower than those normally required in inorganic systems. These methods are discussed with examples taken from the foodstuff industry, the pharmaceutical industry, etc.

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Partly presented at the II. Seminar Thermometric Analysis, Budapest, September 2–7, 1980.     

Development of palladium(II)-catalyzed oxidative cyclization of olefinic keto and/or lactone esters

A highly efficient palladium-catalyzed oxidative cyclization of olefinic keto and/or lactone esters, which features a catalytic cyclization employing one atmosphere of oxygen as a reoxidizing agent, is developed.     

The determination of inorganic chlorine compounds by chemiluminescence reactions

A method is described for the determination of chlorine, chlorine dioxide and hypochlorite in aqueous solutions, involving measurement of the chemiluminescence produced during alkaline oxidation of luminol in the presence of hydrogen peroxide. Two different analytical procedures are employed, one based on a pulse technique and the other on continuous flow. Micromolar or submicromolar quantities can be detected.     

Extraction-chromatographic determination of hydroxysulfo compounds

Conditions of the extraction of naphtholsulfonic acids and azo dyes with an acetone-diacetone alcohol mixture from a saturated solution of ammonium sulfate in the presence of N-cetylpyridinium chloride were optimized. A procedure was developed for the determination of naphtholsulfonic acids and azo dyes in the presence of naphthols on the basis of extraction with a mixture of solvents and an analysis of the concentrate by paper chromatography with elution with the same mixture in the presence of water.