Abstract The Complexes (Bu4N)[TcO(MoS4)2] and Tc- (PPh3)2(MoS4)2 were prepared. The former complex has a much lower Tc-O stretching frequency than is generally found gor the TcO3+. moiety. The latter technetium(IV) Complex was obtained by the reduction of Tc(v) O(MoS4)2− with triphenylphosphine and also by the substitution reaction of TcCl4(PPh3)2 with MoS42-. Previous reductions of this nature have led to the isolation of species that differ by two formal oxidation state numbers from the oxidant.