Chemical Effects of Isomeric Transition of ^95mTc in Inorganic Tc(IV)-Complexes

Abstract

Nuclear transformation / Isomeric transitions/Technetium/Hot chemistry SummaryThe chemical effects of the isomeric transition of ' 5m Tc have been investigated in potassium and ammonium hexachloro-technetate(IV) in solution and solid matrix. The retention of ,5g Tc in sulphuric solution was found to be close to zero. Change of the acid concentration had no effect. Nor was 3 Μ HQ solution much different. The retentions for the solid matrices were found to be higher than 70%. The unretained 9 5g Tc appeared as cationic, hydrated Tc0 2 , [TcQ 5 (H,0)]' and TcO; species. The last species only amounted to about 1 %.

Chemical Effects of the Nuclear Isomeric Transition 95mTc-95Tc in Some Solid Pertechnetates

“…The similarity of the distribution of the active rhenium in the neutron irradiated ammonium perrhenate to the '®®Tc [23] and practically every decay evet must lead to an Auger cascade, so that, at least momentarily, the will acquire a substantial positive Charge. The same dilemma is presented as was described in a previous paper on the hexahalo-technetates arises [2]. Failure to neutralize most of the charging consequent on the Auger cascade should lead to frequent rupture of the TcOj by Coulombic repulsion as the charging distributes itself over the molecule.…”

Scavenging of Tc(V) Formed by I.T. in 95mTcO- 4 Solutions

“…9 TcC>4 with Sn 2+ in the presence of the same ligands at pH = 11.5 leads to the formation of 96% [Tc0 2 L] + , 3% cation "X" and 1% neutral product. At lower pH, the yield of the latter increases whereas the proportion of cation "X" does not change significantly.…”

“…It is reasonable to assume the participation of oxidizing radiolytic products (OH*, HO2 ) in this process. The majority (three or four) of the Auger electrons have kinetic energies less than 2 keV [9], so that there will be a localized radiolysis of the aqueous medium in the close vicinity of the nascent 9Sg Tc. If the ligand molecules are inside the radiolytic zone they have a chance to prevent the 95g Tc to react with the oxidizing products.…”

Chemical Effects of I.T. of 95mTc in a M2TcF6 Solid Matrix and in Solutions

“…The Mo powder was dissolved in 30% H2O2 using a reflux system and '^'"Tc was separated as TcOj as previously described [1,4].…”

“…of in ammonium and potassium hexachlorotechnetate have been studied both in solutions and solid matrices [1,2], The retention of in Solution was found to be dose to zero. The unretained appeared preponderantly as hydrated TCO2 and cationic species, as Teds (HiO)" and as TcOi.…”