Cuprophilicity? a rare example of a ligand-unsupported CuI–CuI interaction

The reaction of 1,1′-bis(2-pyridyl)octamethylferrocene (L) with [Cu(NCMe) 4 ]BF 4 in CH 2 Cl 2 affords [CuL][CuCl 2 ], the structure of which is determined by a single-crystal X-ray diffraction study; this reveals a remarkably short ligand-unsupported Cu I –Cu I contact of 281.0(2) pm.