The novel monomeric niobium persulfide complex, [Et 4 N][NbO(S 2 ) 2 (bpy)].DMF (I) was synthesized by the reaction of NbO(SPh) 4 - with elemental sulfur in the presence of 2,2'-dipyridyl in DMF. The reaction of I with carbon disulfide (CS 2 ) and dimethylacetylene dicarboxylate (DMA) affords [PNP][NbO(CS 3 )(S 2 )(bpy)] (II) and [Et 4 N][NbO(S 2 C 2 (CO 2 Me) 2 )(S 2 )(bpy)].DMF (III) complexes, respectively. In this reaction, insertion reactions of the electrophile occurred at only one site of two equivalent disulfide ligands. In each complex, the Nb atom is seven coordinated and the anion has a distorted pentagonal bipyramidal geometry.