The Potential of Phosphinimines as Building Blocks for a New Generation of Radiopharmaceuticals

Reaction of Ph 3 P˭NSiMe 3 with NH 4 ReO 4 produced the ion pair Ph 3 P˭NH 2 + ReO 4 - which was characterized by spectroscopic data and X-ray crystallography. The thermolysis of this ion pair gave the neutral Re(VII) complex: Ph 3 P˭N-ReO 3 in good yields. The reactions of 99m TcO 4 - or 188 ReO 4 - with Ph 3 P˭N-SiMe 3 also produced the metallic radioisotope analogues of the ion pair: Ph 3 P˭NH 2 +MO 4 - (M = 99m Tc or 188 Re) which on heating produce the neutral species Ph 3 P˭N-MO 3 (M = 99m Tc or 188 Re). The implications of such small molecule 99m Tc or 188 Re complexes for the development of a new genre of radiopharmaceuticals will be discussed.