[Ni23Se12(PEt3)13] Revisited: Isolation and Characterization of [Ni23Se12Cl3(PEt3)10].

The reaction of [Ni(1,5-COD)2] (1.0 equiv), PEt3 (0.04 equiv), SePEt3 (0.52 equiv), and [NiCl2(PEt3)2] (0.07 equiv) in a mixture of toluene and THF results in the formation of [Ni23Se12Cl3(PEt3)10] (1), which can be isolated in moderate yield after workup. Complex 1 was characterized by NMR spectroscopy, ESI-MS, and X-ray crystallography. This open-shell nanocluster features a central [Ni13]7+ anticuboctahedral kernel, which is encapsulated by a [Ni10(μ-Se)9Cl3]- shell, along with ten PEt3 ligands and three (μ4-Se)2- ligands. On the basis of our spectroscopic and crystallographic analysis, coupled with in situ spectroscopic monitoring, we believe that the previously reported nanocluster, [Ni23Se12(PEt3)13], is actually better formulated as [Ni23Se12Cl3(PEt3)10].