Über Reaktionen zwischen Phosphortrichlorid und Cyclohexen unter dem Einfluß von Y-Strahlung und von Wärme

Abstract

1-chlorocyclohexyl-phosphorus dichloride is formed in a Kharasch type chain reaction when 7-rays act on mixtures of phosphorus trichloride and cyclohexene. The G-value is proportional to the reciprocal square root of the dose rate and readies a maximum at 100 °C. The activation energy of the rate determining step PC12C6H10-+PC13 PC12C6H 10C1 + PC12-was found to amount to 6, 7 kcal/mole. At higher temperatures, the yield strongly decreases since another chain reaction predominates which produces cyclohexyl-phosphorus dichloride. The two chains have a common propagation step. 1-chlorocyclohexyl-phosphorus dichloride and cyclohexyl-phosphorus di chloride are also thermally formed at temperatures above about 150 °C.Die Addition von Polyhalogeniden wie CC14 und CBr4 an Olefine unter Bildung von 1.1.1.3-Tetrahalogeniden ist durch die Arbeiten von K h a r a s c h , J e n s e n und U r r y 1 seit langem bekannt. A udi Phos phortrichlorid vermag sich an Doppelbindungen als CI + PC12 anzulagern, wie am Beispiel des Okten-1 gezeigt worden is t2. Zur Auslösung solcher Reak tionen dient die thermische Zersetzung zugefügten Diacetylperoxyds; in manchen Fällen ist auch Licht als Katalysator geeignet. K h a r a s c h et al. formulier ten die Addition der Polyhalogenide an Olefine als radikalische Kettenreaktion mit den Wachstums schritten Die Analyse des ReaktionsgemischesAls Strahlenquellen dienten 60Co-Präparate von 100 bis 3000 Curie. Die Proben wurden in abge-3 E. J u n g e r m a n n , J. J . M c B r i d e , R. C l u t t e r u . A. M a i s , J.org. Chemistry 27, 606 [1962].

The Competition Kinetics of Unbranched Chain Processes of Free-Radical Addition to Double Bonds of Molecules with the Formation of 1:1 Adducts

“…This kinetic model of free-radical addition to the double bond of an organic compound with participation of three radical types in the chain propagation is given by the following reaction scheme. Here I is the initiator, e.g., peroxide [l, 8,9]; Rb is some reactive radical; A and B are hydrogen [ 1 -3, 8,9] is PCl2 [4,5] or CCI3 [6], alkyl [l, 71, a-hydroxyalkyl [l-3,8,9], or other functionally substituted radical [l] (the addend radical); R, is the formyl [2,3,9], alkenyl (beginning with propenyl) [ 1,4 -81, a-hydroxyalkenyl [2,3,8], or other functionally substituted radical [l]; R; is the saturated adduct radical [l -91; RoA, ROB, and RIA are saturated compounds; R2B is an unsaturated compound; R3A and R3B are the final (nonradical) products, the 1 : 1 adducts; and Prod are the final products of combination or disproportionation of radicals. Scheme I includes two pairs of competing reactions l a vs. l b and 3 vs. 4.…”