NEUTRAL TRIS OXIME COMPLEXES OF TECHNETIUM(III)

Abstract

A new class of neutral Technetium(III) complexes has been discovered; these complexes, which contain three oxime ligands and a halogen, are seven-coordinate intermediates in the synthesis of our boron-capped myocardial and brain imaging agents (BATO complexes). We report here the chemistry and biodistribution of these new compounds. The tris oxime complexes, TcCl(DMG)3 and TcCl(CDO)3 (DMG = dimethylglyoxime, CDO = cyclohexanedionedioxime), can be prepared from TcO4−, using triphenylphosphine (99-Tc) or SnCl2 (99m-Tc) as the reductant. The compounds have been fully characterized by elemental analysis, NMR, FAB and FD-MS and conductivity. An x-ray crystal structure of TcCl(DMG)3 reveals that the Tc is bonded to three N-bonded DMG ligands and a chlorine atom in a face-capped trigonal prismatic array. Biodistribution studies in rats show that several of the tris oxime complexes exhibit significant myocardial uptake. Washout from the heart was slower than is seen with the boron-capped complex, TeCl (CDO)3MeB (SQ 30,217).