Reactions of energetic fluorine-18 atoms with fluoromethanes. Formation of CH18F and CF18F

The Spin States of lodocarbene Produced from the Reactions of Fission lodine with Methane

“…These results agree with the suggested spin State assignments by YANG and M AROLEWSKI [5] who generated iodocarbene via the photolysis of iodoform in the liquid phase. These conclusions also show that all the monohalo-carbenes experimentally studied to date (CHF, CHCl and CHI) have ground states with a singlet spin State [14,15], The formation of iodocarbene in the higher energy triplet spin State by the directly produced fission iodine can be qualitatively understood through a consideration of the higher recoil energjes of these isotopes. These iodine species with initial recoil energjes around 25 MeV, undoubtedly react at higher energies than the indirectly produced iodine which has a maximum initial recoil energy of 2 to 3 ev.…”

Perfluoropropene as Scavenger in 18 F-Recoil Systems

“…In earlier studies of recoil reactions of 18 F in fluoroalkanes [3,4,18,19] (without C 3 F 6 as scavenger) it has been found that the predominant species we are dealing with are thermal or near thermal 18 F-atoms; the total hot yield of fluoroalkyl-products is only 10-15%. Thus the 18 F-compounds formed in the Ne/C 3 F 6 and fluoroalkane/C 3 F 6 systems are mainly products of reaction sequences starting with the addition of thermal 18 F-atoms to C 3 F 6 .…”

“…From the fact that the yield of 18 F-CF 4 is not higher than for systems without C 3 F 6 [3,18,19] (see Table 4) and no 1 F-C 3 Fg is formed it can be concluded that for C 3 F 6 k, abstraction <k addition for CF 3 · and C 3 F 7 · radicals Isomer-distribution of the perfluoroalkanes With the different bath-gases approximately the same ratios for the isomers of the different alkanes are found. In Fig.…”

Reactions of 18F Recoil Atoms in Gaseous CF3—CF3 and CF3—CF2H

“…The earlier experiments of WOLFGANG et al [1 -3] of SPICER [4] and of ROW-LAND and co-workers [5,6] were dealing with the reactions of 18 F with(fluoro)methanes and the subsequent unimolecular decomposition of the products formed. More recently ROOT and co-workers [7][8][9][10][11][12][13][14] investigated the reactions of recoil 18 F-atoms in fluoroethanes such as CF3-CH3 and CF 2 H-CH 3 .…”