Chemical Effects of the (n,y) Reactions in Dichlorotriethylene Tetramine Complexes of Cobalt (111) and Rhodium(lll)

Abstract

Cis -cobalt( 111) and rhodium( 111) dichlorotriethylene tetramine chloride which were labelled with 3e CI in the anion and cation, trans-dichlorotriethylene tetramine cobalt(lll) chloride labelled with 3, C1 in the anion and cation, and cis-and transdichlorotrien cobalt (111) chloride labelled with e0 Co in the metal atom, have been irradiated with thermal neutrons in a flux of 10 u neutrons cm -2 sec -1 for ten hours. Study of the effects of the (n,y) reaction has shown that in the case of cis-dichlorotriethylenetetramine cobalt(lll) chloride after irradiation the amount of new product cations are about five times (by chloride labelling) to seven times (by cobalt labelling) the amount of original cation left. JVcros-dichlorotriethylene tetramine cobalt (111) chloride and cis-dichlorotriethylene tetramine rhodium(lll) chloride, show a ratio of 2:1 new product cations to original cation as measured by cobalt labelling. When the anions are considered, it has shown that with cis-dichlorotriethylene tetramine cobalt(lll) chloride the amount of chloride ion left after irradiation is about half of the starting amount.Traiu-dichlorotriethylene tetramine cobalt (111) chloride shows about the same amount of chloride ion left after irradiation as before irradiation, whilst cis-dichlorotriethylene tetramine rhodium (111) chloride shows about one half to three-quarters of the chloride ion present after irradiation. A unique feature of the results is that from 200,000 to 500,000 Metal-Cl bonds are broken for each n,y reaction, suggesting that the HARBOTTLE and STJTIN hot zone model must be expanded to include a larger number of molecules. ZusammenfassungIm Anion und Kation mit 3e Cl markiertes cis-Kobalt(lll)-und -Rhodium(lll)dichlortriäthylentetraminchlorid, im Anion und Kation mit '"Cl markiertes <rans-Dichlortriäthylentetramin-kobalt(lll)chlorid und im Metallatom mit 60 Co markiertes cis-und <ra?is-Dichlortrienkobalt(lll)chlorid wurden mit thermischen Neutronen in einem Fluß von 10 11 Neutronen cm _2 sec _1 zehn Stunden bestrahlt. Die Untersuchung der Auswirkungen der (n,y)-Reaktion hat gezeigt, daß bei cisDichlortriäthylentetraminkobalt(lll)chlorid nach Bestrahlung die neu gebildeten Kationen die verbliebenen Ausgangskationen mengenmäßig um das Fünffache (Chloridmarkierung) bis Siebenfache (Kobaltmarkierung) übersteigen. Bei transDichlortriäthylentetraminkobalt(lll)chlorid und cis-Dichlortriäthylentetraminrhodium(lll)chlorid beträgt das durch Kobaltmarkierung bestimmte Verhältnis von neu gebildeten zu den ursprünglichen Kationen 2:1. Was die Anionen betrifft, so hat sich gezeigt, daß bei cü-Dichlortriäthylen-tetraminkobalt(lll)chlorid die nach der Bestrahlung übrig-gebliebenen Chloridionen mengenmäßig etwa die Hälfte der Ausgangsmenge betragen. Tmne-Dichlortriäthylentetraminkobalt(lll)chlorid weist nach der Bestrahlung etwa dieselbe Menge an übriggebliebenen Chloridionen wie vor der Bestrahlung auf, während cisDichlortriäthylentetraminrhodium(lll)chlorid nach Bestrahlung etwa die Hälfte bis drei Viertel der vorhandenen C...

"Super Hot Zones" by Nuclear Recoil in Amine-Complexes of Co, Rh and Ir?

“…* By K. RÖSSLER and J. OTTERBACH, Institut für Radiochemie der Kernforschungsanlage Jülich GmbH, Jülich, Federal Republic of Germany (Received December 1, 1970) Two recent papers of GABDNEB et al [1,2] envisaged a modification of the "hot spot" model for chemical effects of nuclear transformations in solids. The authors studied the consequences of (η,γ)-reactions in complexes of thé type [Me(NH 3 ) 6 Cl]Cl 2 and [Me(trien)Cl 2 ]Cl (Me = Co, Rh, Ir), which were specifically labelled with^Cl, eo Co and 192 Ir.…”

“…In general, it seems rather unlikely that the attempt to observe macroscopic changes can yield any information on the chemical effects of nuclear processes, which occur in a microscopic region. This is particularly true when the neutron doses are relatively small such as those applied by GABDNEB et al [1,2]. Furthermore, it is hard to conceive of any mechanism which would give rise to the observed 95% of free ^Clafter neutron activation of [Ir(NH,) 5 M Cl]Cl 2 , except a total decomposition during irradiation.…”

“…Further complications arise because most of the commercially available Rh-salts contain Ir-impurities. Since these nuclides are present practically carrier-free in a great variety of new valence states and chemical forms, it is not possible to add all the corresponding hold back carriers, nor did GARDNER et al [1,2] report to have made any attempt to do so. Therefore we suspected a significant adsorption of radiochemical impurities on the AgCl-precipitates.…”