A novel mixed-valence trinickel complex containing nickel(I), nickel(II) and iodonium moieties

The title complex, [{Ni(C14H28N2S2)2}NiI2]+I−·CH3CN forms as a crystalline minor product in the oxidation of Ni(C14H28N2S2) with iodine. X-ray analysis reveals that the trinuclear monocations are racemic and consist of two neutral, square-planar Ni(II)N(amine)2S(thiolate)2 units bridged via the thiolate ligands by an unusual NiI2 + group that can be described as containing Ni(I) and I(I) species. The Ni(I) atom is coordinated to two S(thiolate) ligands, an iodide ligand and an iodonium atom in an unusual distorted trigonal-pyramidal arrangement. The I(I) ion is coordinated to the remaining two S(thiolate) ligands [SIS=171.91(7)°] and to the Ni(I) ion [Ni(I)I(I)=3.0298(14) Å] to yield a T-shaped geometry. Pyramidal coordination at the four sulfur atoms gives each cation a U-shaped conformation in profile.