[Tc(OH2)(CO)3(PPh3)2](BF4) has been used as a synthon for reactions with smallinorganic ligands with relevance for the treatment of nuclear waste solutions such as nitrate, nitrite, pseudohalides, permetalates (M = Mn, Tc, Re), and BH4–. The formation of bond isomers and/or a distinct reactivity has been observed for most of the products. [Tc(NCO)(CO)3(PPh3)2], [Tc(NCS)(CO)3(PPh3)2], [Tc(CN)(CO)3(PPh3)2]