Thioether-ligated nickel(i) complexes for the activation of dioxygen

Abstract

The preparation of phenyltris[1-adamantyl(thiomethyl)]borate [PhTt^Ad], which incorporates the large 1-adamantyl thioether substituent, is described. This derivative was sought to permit the preparation of four-coordinate nickel(I) complexes. Following a synthetic scheme for the related tert-butyl ligand, [PhTt^But], the following complexes were prepared and characterized fully, [PhTt^Ad]Ni(CO), [PhTt^Ad]Ni(PMe₃) and [κ²-PhTt^Ad]Ni(η²-CH₂SAd). The last species is a degradation product resulting from attempted reduction of the nickel(II) precursor, [PhTt^Ad]NiCl, in the absence of a ligand suitable for trapping the nickel(I) fragment.