Reactions of Bromine Activated by Bromine−82m Isomeric Transition and Radiative Neutron Capture in Liquid and Solid Carbon Tetrachloride and n-Hexane

Abstract

New methods have been developed for obtaining 82Br and 82Brm organic retentions produced by 82Brm isomeric-transition reactions and radiative neutron capture by 81Br, respectively. No isotope effect was found for 80Brm and 82Brm reactions activated by the (n, γ) process. The 82Brm (I.T.) 82Br process was found to produce 82Br organic retentions nearly twice as high as the 80Brm and 82Brm organic retentions produced by the (n, γ) process. Effects of solidifying samples indicate a clumping of bromine molecules upon freezing. Product analyses indicate similar reaction mechanisms for the (n, γ) and (I.T.) activated reactions.

The Gas to Liquid to Solid Transitions in Halogen Hot Atom Chemistry

“…In previous studies of halogen hot atom chemistry in the condensed state [4][5][6][7], various molecular and caging mechanisms have been assumed, based upon systematic trends and additive studies on product yields. At the present time there is still no good understanding of the (n, y) and (IT) activation processes in the condensed states.If what RICHARDSON and WOLFGANG [2] report for 18 F reactions in CH 3 F is generally true for gas to condensed phase transitions in hot atom chemistry, we should observe a similar effect for bromine reactions activated by radiative neutron capture in CH 3 F, rather than the linear increase found by RICE and WILLARD [3],In this Note we report the effect of density change upon the 80 Br organic product yields from the (η, γ)activated reactions in CH 3 F.A description of our sample making techniques, irradiation procedures, and extraction techniques can be found elsewhere [8][9][10][11], with the following modifications: (1) Small (^ 1 ml), thick, quartz ampoules were filled with sufficient CH 3 F and Br 2 (at 0.0167 mole fraction Br 2 ) so that, when the ampoule was sealed and thawed, the homogeneous mixture was in the liquid state. The ampoules were filled to maximum capacity, minimizing gas phase contributions.…”

“…A description of our sample making techniques, irradiation procedures, and extraction techniques can be found elsewhere [8][9][10][11], with the following modifications: (1) Small (^ 1 ml), thick, quartz ampoules were filled with sufficient CH 3 F and Br 2 (at 0.0167 mole fraction Br 2 ) so that, when the ampoule was sealed and thawed, the homogeneous mixture was in the liquid state. The ampoules were filled to maximum capacity, minimizing gas phase contributions.…”

Recoil and chargin contributions to organic incorporation of radiobromine atoms following neutron activation

“…Probability of Internal Conversion in an n,y Activation. The general expression for organic yield from , events, eq 3, then can be simplified, in the case of very dilute solutions, to T°org = /cR°org,c (8) Substituting the observed value of 0.495 ± 0.005 for P°OTg,c (from the pure internal conversion 82mBr(IT)-82gBr process), eq 8 permits an estimation of /" for each , process for which suitable organic yield measurements can be obtained. Table II lists values of /" for the 79Br(n,y)80mBr, 81Br(n,y)82gBr, and 81Br(n,7)82mBr transformations.…”

Effects of a Collapsing Molecular Environment on High Energy Bromine Reactions in Ethane

“…For the determination of individual organic product yields (lOPY) in the various samples, a variable temperature gas Chromatograph similar to the one previously described [17] but modified to handle the direct injection of high pressure gaseous and liquid phase samples [13] was used employing a scintillation counter with a flow through cell. The direct injection of high pressure and liquid samples was necessary to prevent loss of volative labelled organic products such as CHsBr.…”