Rückstoß‐Reaktionen des Tritiums mit organischen Verbindungen

Schmidt-Bleek, Friedrich; Rowland, F. S.

doi:10.1002/ange.19640762202

Cited by 4 publications

(3 citation statements)

References 41 publications

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“…Die Ruck-stoDenergie des Kerns betragt Beim P-Zerfall setzt sich die Ruckstorjenergie vektoriell aus den Beitragen des emittierten Elektrons nach GI. ( 5 ) und des Neutrinos zusammen. Die resultierende RuckstoBenergie hat eine Verteilung zwischen 0 und ER(maX); der maximale Wert ergibt sich beim Einsetzen der maximalen p-Energie in GI.…”

Section: Introductionunclassified

Chemische Folgen von Kernumwandlungen in Festkörpern

Müller

1967

Angewandte Chemie

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Kernreaktionen und radioaktive Zerfalle bieten die Moglichkeit, chemische Reaktionen ,,nackter '' Atome zu untersuchen. Das Interesse an derartigen chemischen Folgeprozessen von Kernurnwandlungen fand seinen Niederschlag in bereits zwei internationalen Symposien [I 321. In Festkorpern verlaufen die chemischen Reaktionen von RiickstoJkernen mit weniger als I keV Energie nicht iiber Schmelzzustande, sondern iiber Bereiche geringer Fehlordnung. Die vergleichsweise grorjten Erfolge wurden bisher bei der Untersuchung von Gasen erzielt, wobei die Reaktionen mit Tritiumatomen aus den Kernprozessen 3He(n,p)3T und 6Li(n,a)3T und rnit 1lC-Atomen aus IZC(y,n)llC und anderen Kernreaktionen irn Vordergrund stehen r4-81. Weniger erfolgreich waren Untersuchungen an Flussigkeiten, hauptsachlich an organischen Halogenverbindungen [91. Am geringsten sind unsere Kenntnisse uber die chemischen Folgen von Kernurnwandlungen [*] in Festkdrpern [10-141. II. Der KernriickstoS [I51Der beim Einfang eines thermischen Neutrons entstehende Zwischenkern ist um 6 bis 8 MeV energiereicher als der Kern im Grundzustand. Diese uber-schul3energie wird meist als y-Strahlung abgegeben. Ein y-Quant der Energie EV hat einen Impuls (c Lichtgeschwindigkeit).Wegen der Impulserhaltung erfahrt der Folgekern den gleichen Impuls p. Die kinetische (RiickstoR-)Energie ER eines Kerns der Masse M und der Geschwindigkeit ER Lev], = -536 (Ey in [MeV])z M

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Section: Introductionunclassified

Chemische Folgen von Kernumwandlungen in Festkörpern

Müller

1967

Angewandte Chemie

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“…Crotyl chloride in moist acetone yields mainly (5) and (6), while methallyl chloride gives mainly m-cresol together with the cyclic compounds (10)-(12)[16bI.…”

Section: I*1mentioning

confidence: 99%

Nickel‐Catalysed Reactions of Allyl Halides and Related Compounds

Chiusoli¹,

Cassar²

1967

Angew. Chem. Int. Ed. Engl.

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Allyl compounds react with carbon monoxide, or with carbon monoxide and acetylene, in the presence of tetracarbonylnickel as catalyst. These catalysts are involvedalso in coupling reactions and addition reactions of activated olefins and ketones. Reactions of this type can be used for the preparation of unsaturated aliphatic acids, esters, nitriles, hydrocarbons, alicyclic ketones, keto acids, keto esters, diketones, lactones, phenols, and other compounds. The reactions proceed via n-allylnickel complexes. In earlier publications L1 -21 we described two reactions for the preparation of unsaturated acids or esters by "carbonylation" with tetracarbonylnickel as the catalyst: Reaction (a) gives b,y-unsaturated compounds, while reaction (b) yields compounds with double bonds in both the a,@ and B,E positions, the K,@ substituents being cis to each other. Reaction (a) is carried out at room temperature and at 2-3 atm pressure. The reaction is suppressed at higher pressures unless the temperature is also raised, whereas lower pressures favor dimerization of the allyl groups. Generally the yields do not exceed 50%. Reaction (b) is best carried out at room temperature and at atmospheric pressure (yield up to 80 %). In both cases, the start of the reaction is characterized by a strong reddish coloration of the reaction mixture, which changes to green toward the end of the reaction. If the compound is a secondary halide that can rearrange to a primary halide, it reacts in the primary form; e.g. CH3-CHCl-CH=CH;, reacts as CH3-CH=CH-CH2C1 [ usual mild conditions (0-50 "C), but rearrange first to give secondary halides. Preparation of Unsaturated Acids and Esters fromWhen inert solvents (e.g. ethers or aromatic hydrocarbons) are used, the products are acyl halides [2a, 353. Reactions (a) and (b) are best carried out in dilute solution in the presence of an excess of tetracarbonylnickel (more than 1 mole per mole of allyl compound). Table 1 shows some methyl esters obtained via equation (b). No attempt was made to determine the optimum conditions for their syntheses. Reaction (b) may also yield by-products, such as acrylic acids or esters, from acetylene and carbon monoxide; however, the formation of these products can be suppressed by neutralization of the hydrogen chloride liberated. 3-Chloro-1-propyne (propargyl chloride) reacts with carbon monoxide, water, and tetracarbonylnickel to give 2,3-butadienoic acid and itaconic acid. The similarity between this and the reaction of allyl chloride is, however, purely formal. RCH=CH-COOCH3 R"-= CHz=CH-CHz-CH~-CH=CH-CHZ-CH2= C(CH3)CHz-CH3-CH = CH-CH(CH3)-CH~-C(CH~)=CH-CHZ-CH,-(CH2)2-CH=CH-CH2-CH~-(CH~)~-CH=CH-CHZ-CH,-(CH2)6-CH= CH-CHz-CH~-(CH~)I~-CH=CH-CHZ-CH~-C(CH~)~-CHZ-CH=CH-CHZ-H~COCO-CH=CH-CHZ-H~COCO-CHZ-CH=CH-CH~ HsCOCO-CH= CH-CH~-CHECH-CH~-H~COCO-CH=C(CH~)-CHZ-H~C-COO-CH~-CH=CH-CHZ-NC-CHz-CH=CH-CHz- 2-Cyclopenten-1-yl 2-Cyclohexen-1-yl GHs-CH=CH-CHz-H,COCO-CH=CH-CH2-CH=CH-CHZ-CH~-CH= CH-CHz-is a by-product in water/acetone).These reactions are carried out in the presence ...

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“…As the result of these studies some characteristic features of hot tritium reactions have been found and the general model of these reactions have been outlined [1][2]. A number of studies on hot tritium reactions with liquid hydrocarbons have also been carried out [3-101. However the experimental control of condensed systems in more difficult (in particular there is an unsolved problem in finding soluble moderators and effective scavengers).…”

Section: Introductionmentioning

confidence: 99%