COMPLEXES OF LOW OXIDIZED TC-99 AND RE WITH THIOSALICYLIC ACID AND THEIR CHARACTERIZATION IN SOLUTION WITH SOME CNDO-MO CALCULATIONS

Complexation of tectnetium-99 and rhenium in low oxidized forms with t hiosalicylic acid (TSA) were investigated by uv.-vis. spectrophotometr y and HPL-chromatography. By CNDO-MO calculations of the proper struct ure of TSA, the charge densities, ionization potential, electron affin ity and its dipole moment were studied. The violet solutions of the Tc and Re complexes exhibit characteristic bands in the visible at 420,5 90 nm and 410,570 nm respectively. Comparative HPLC studies using MeOH /H2O as a mobile phase indicate the Re-TSA complex to be less stable t han the Tc-TSA complex.