Characterization of a Complex Comprising a {Cu 2 (S 2 ) 2 } 2+ Core: Bis(μ‐S 2 2− )dicopper( III ) or Bis(μ‐S 2 . − )dicopper( II )?

Cores for thought: Structural and spectroscopic studies show that the {Cu2(S2)2}2+ core of [Cu2(tmeda)2(μ-S2)2](OTf)2 (tmeda=N,N,N′,N′-tetramethylethylenediamine; OTf=trifluoromethanesulfonate) is best described as a bis(μ-disulfido(.1−))dicopper(II) complex rather than a bis(μ-disulfido(2−))dicopper(III) complex. This complex represents a new motif in the copper–sulfur chemistry of biologically relevant, synthetic model systems.