Re(V) complexes with an open-chain quadridentate ligand containing two amine and two amido donors. Synthesis, characterization, and solution equilibria of Re(sub 2)O(sub 3)(dioxotetH(sub 4))(sub 2) and [ReO(H(sub 2)O(dioxo-tetH(sub 4)]C1 (dioxotetH(sub 6) = 1,4,8,11-tetraazaundecane-5,7-dione)

A study was conducted to identify mononuclear cationic[M(v)=O](super 3+) (M=Tc,Re) complexes for radiopharmaceutical applications. The open-chain ligand, 1,4,8,11-tetraazaundecane-5,7-dione(dioxo-tetH(sub 6)) with two amine and two amide donors were investigated.