Reaction of [TcNCl4]− with ethylenediamine-N,N'-diacetic acid ligand

Abstract

Abstract The reaction of [99mTcNCl4]– with ethylenediamine-N,N'-diacetic acid (ENDA) has been studied. Starting from [99mTcNCl4]– prepared according to the method of Apparu et al.6, the exchange reaction with ENDA in the presence of stannous tartrate led to the formation of an anionic99mTcN-ENDA complex. The labeling yield was about 90% at pH values of 10.5 and 6.5. In the absence of the reducing agent the formation of99mTcO4 – is reflected in the decrease of the complex yield. The exchange reaction of [99TcNCl4]– with ENDA at pH 6.5 and in the absence of a reducing agent resulted in the formation of the anionic99TcN-ENDA complex and99TcO4 –. The spectrophotometric characteristics (UV-vis. and IR) of the pure complex are similar to those of some tcN2+-complexes with amine ligands. The electrophoretic and chromatographic behaviors of99mTcN- and99TcN-ENDA anions are identical; this proves the formation of the same complex with both radionuclides.