Se₂B₁₇H₁₇: a selenaborane platform for coordination chemistry

Reaction of Se₂B₁₇H₁₇1 with [(dppe)NiCl₂] and N,N'-dimethylnaphthalenediamine (tmnd) typically gives new nineteen-vertex n-[10-(dppe)-10,9,11'-NiSe₂B₁₆H₁₆] 2a (63% yield) and new twelve-vertex [2-(dppe)-closo-2,1-NiSeB₁₀H₁₀] 3 (up to 9% yield) of known structural type. Occasionally, an isomer of 2a, specifically new iso-[10-(dppe)-10-9,9'-NiSe₂B₁₆H₁₆] 2b, is obtained in yields of up to 4.5%. On one occasion, an isopropoxy-substituted derivative of 2a, specifically new [8-(Me₂HCO)-10-(dppe)-10,9,11'-NiSe₂B₁₆H₁₅] 4, was also isolated, a compound presumably resulting from an acetone impurity during the preparative process. Incidental to the work, the [Se₂B₁₇H₁₆]^- anion 5, was isolated as its [tmndH]⁺ salt 5a. New compounds 2a, 2b, 3, 4, and 5a were characterised by multinuclear NMR spectroscopy and mass spectrometry, as well as by single-crystal X-ray diffraction analyses, and by concordance with the results of DFT nuclear shielding calculations.