Synthesis and properties of dioxo Tc/V/ cationic complexes with nitrogen containing ligands

Abstract: A series of Tc/V/ cationic complexes was synthesized by electrochemical reduction of TcO ₄^– . The electrolysis was performed in aqueous media containing amines as ligands: en, dien, trien and 1,3-dap^*. The combination of different techniques allows to propose the general formula [TcO₂/amine/₂]⁺ for these compounds. Electrodeposition of TcO₂ was a competitive reaction. The UV spectra were compared with those for other Tc/V/ amine complexes. The presence of two peaks, one in the range 303–312 nm and the other in 230–240 nm, could be verified. The latter was markedly sensitive to pH changes. Preliminary studies showed that kinetic stability decreases in the sequence en, 1,3-dap, trien, dien. The decomposition rate increased when the pH was lowered.