Reaction of (np 3)Ni (np 3=tris(2-diphenylphosphinoethyl)amine) with CS 2, SCNPh, or COS affords (np 3)Ni(η 2-CS 2) 5, (np 3)Ni(η 2-SCNPh) 9), and (np 3NiCO 12, respectively. Methylation of 5 by MeOSO 2F, followed by NaBPh 4 addition, leads to [Ph 2 PCH 2CH 2N(CH 2CH 2PPh 2) 2Ni(C S 2Me)]BPh 4 6 through intramolecular attack by a phosphorus atom of np 3 on a η 2-dithiomethyl ester group formed in situ. The structure of 6 has been determined from counter diffraction data. Crystal data are: a 28.148(16), b 14.448(8), c 33.922(17) Å, β 112.11(4)°, monoclinic, space group C2/ c, Z = 8. The structure was solved by the heavy-atom method and refined by full-matrix least-squares. Refinements converged at the conventional R factor value of 0.095 for the 1989 reflections having I⩾ 3σ I.