Inorganic Chemistry, Vol.52, No.11, 6627-6634, 2013
A Comparative Study on Dinuclear and Multinuclear Ni(II), Pd(II), and Pt(II) Complexes of a Thiolato-Functionalized, Benzannulated N-Heterocyclic Carbene Ligand
Dimeric thiolato-bridged Ni(II) and Pt(II) NHC complexes 2 and 4 have been synthesized from ligand precursor A through a combined and in situ deprotonation/hydrolysis protocol of a thioester-functionalized benzimidazolium salt in the presence of the respective metal salts. Reactivity studies of 2 and 4, and their previously reported Pd(II) analogue 1a toward either Me3OBF4, NaOH, or Na2S center dot 9H(2)O revealed clear differences. Complex 2 decomposed when treated with Me3OBF4. On the other hand, its reaction with aqueous NaOH solution in the presence of NaBF4 yielded trinuclear [Ni3S3O] complex 6, which possesses an interesting [Ni3S3] triangle with a capping mu(3)-oxido ligand. Pt(II) analogue 4 was converted to the tetranuclear [Pt4S4] macrocycle 5 when treated with Me3OBF4, in analogy to the result from 1a, while no defined products could be isolated when 4 was treated with either NaOH or Na2S center dot 9H(2)O. Pd(II) analogue 1a reacted with Na2S center dot 9H(2)O to give the tripalladium [Pd3S3S] complex 7 bearing a capping mu(3)-sulfido ligand.