Contributions to the chemistry and photochemistry of TcCl62-

Studies have been conducted on the properties of 99Tcsup(m)Cl62-, the species that results from the reduction of pertechnetate with HCl. It is documented that a photoaquation may occur when the acidity of the medium is reduced and the hexahalotechnetium is exposed to visible light while in an aqueous solution. Evaporation of the HCl solution to dryness, followed by redissolution of the hexahalotechnetate in acetonitrile, gives a technetium-containing intermediate that can readily be complexed with organic ligands under non-aqueous conditions. As an example, the reaction of TcCl62- with 8-hydroxyquinoline results in compounds that are highly soluble in chloroform, have an octanol/water partition coefficient of 28, and can be resolved into two complexes upon electrophoresis. It is proposed that these products are the TcCl2L2 and TcL3+ complexes (L representing a polydentate ligand), examples of the liposoluble compounds that can be readily prepared using the conditions described in this paper. (author)