New Synthetic Routes to a Disulfidodinickel(II) Complex: Characterization and Reactivity of a Ni2(µ-η22-S2) Core

Activation of elemental sulfur by the monovalent nickel complex [PhTttBu]Ni(CO) [PhTttBu = phenyl{tris[(tert-butylmethyl)thio]methyl}borate] generates the disulfidodinickel(II) complex 2. This species is alternatively accessible via thermal decomposition of [PhTttBu]Ni(SCPh3). Spectroscopic, magnetic, and X-ray diffraction studies establish that 2 contains a µ-η22-S2 ligand that fosters antiferromagnetic exchange coupling between the NiII ions. This observation is in contrast to the lighter congener, oxygen, which strongly favors the bis(µ-oxo)dinickel(III) structure. 2 oxidizes PPh3 to SPPh3 and reacts with O2, generating several products, one of which has been identified as [(PhTttBu)Ni]2(µ-S) (3).