Recombination and Disproportionation Reactions of Monochloroethyl and Trichloromethyl Radicals

Abstract

The recombination and disproportionation reactions of CH2CH2Cl and CCl3 radicals have been investigated. Trichloromethyl radicals and monochloroethyl radicals were produced by photolyzing carbon tetrachloride in the presence of ethylene. The main features of the resulting reaction mechanism are given by reactions (1) to (8) CCl4+hν→CCl3+Cl,Cl+C2H4→C2H4Cl,2C2H4Cl→(C2H4Cl)2,2C2H4Cl→C2H4+C2H4Cl2,2C2H4Cl→C2H5Cl+C2H3Cl,2CCl3→C2Cl6,C2H4Cl+CCl3→CCl3C2H4Cl,C2H4Cl+CCl3→CHCl3+C2H3Cl.The following rate constants have been determined k4/k3≤0.1;k5/k3≤0.1;k7/(k312k612)=2.5±0.2,and k8/k7=0.11±0.02.

Kinetics of Cl Atom Reactions with C2H5Cl and C2H4Cl Radical and the Disproportionation of 2C2H4Cl at 298 K and at Millitorr Pressures

“…Only measurements for the disproportionation−recombination ratios ( k d / k c ) for C 2 H 4 Cl radicals are known. They have been studied between 3 and 760 Torr pressures by the reaction scheme: Rate constant ratios for reactions 12a and 12c are reported as 0.05, 0.1, 0.21, and 0.36, whereas the ratios for reactions 12b and 12c are 0.1, 0.21, and 0.09 . Concerning the disproportionation variant 12b, we could find neither traces of dichloroethane in the mass range 98−100, nor any measurable increase of mass 28 signal intensity over that from the C 2 H 5 Cl fragmentation.…”

Thermal chlorine-38 atom reactions with ethylene

“…Wijnen et al also used ultraviolet SC,H,Cl -.+ CH,ClCH,CH,CH,Cl ( 5 ) C1 transfer C,H,Cl t C,H4C1-C,H, t C,H,Cl, (6) H transfer C,H,Cl + C,H,Cl-C,H,Cl + C,H,Cl ( 7 1 photolysis of C C 4 as a C1-atom source for reaction with ethylene. 6 In these experiments, disproportionation products from C1 and H transfer between C2H4C1 radicals were observed, as in (6) and (7). The yields of the observed two-carbon products (C2H3C1, C2H5C1, CzH4C12) indicated that the disproportionation processes 6 and 7 were 50.1 as probable as combination 5 .…”

Photolyse De l'IODURE De Vinyle en Solution Dans Le Tetrachlorure De Carbone

“…I1 semble donc que la formation du butadiPne doit &re attribuke surtout A la reaction [7], sans toutefois rejeter totalement une participation de la rCaction [S] E n admettant la rkaction [6] pour la formation d u chlorure de vinyle, on devrait trouver une dCpendance liniiaire de la concentration en CC14. E n fait, on trouve une dCpendance du carrk de la concentration (Fig.…”

“…Mais les rkactions [6] e t [9] sont compCtitives; on peut alors expliquer que la formation du chlorure de vinyle dCpende du c a r d de la concentration en iodure de vinyle. Dans le cas de l'CthylCne, la dkpendance de la concentration n'est pas aussi simple (Fig.…”

“…Dans le cas de l'CthylCne, la dkpendance de la concentration n'est pas aussi simple (Fig. 3); ce qui peut s'expliquer par le fait que la vitesse de formation de l1Cthyl6ne dCpend 8 la fois des vitesses des rkactions [6] e t [9], alors que celle du chlorure de vinyle ne dCpend que de la vitesse de la rCaction [9].…”