Benzene−Copper(I) Coordination in a Bimetallic Chain Complex

The solvothermal reaction of CuCl and ZrCl4 in benzene yields ((bz)CuCl3)2Zr (1) (bz = η2-benzene), which has
been characterized by single-crystal X-ray diffraction with a = 6.1206(4) Å, b = 11.1242(4) Å, c = 13.6222(6)
Å, β = 93.675(3)° in the monoclinic space group P21/m, Z = 2. 1 adopts a one-dimensional chain structure
constructed from zirconium chloride octahedra and [(bz)CuCl3]2- tetrahedra. The [(bz)CuCl3]2- units are shown
to be metal halide analogues of the phosphonate unit [RPO3]2-. Interchain interactions link chains of 1 along the
crystallographic c direction via an edge-to-face π-stacking of the coordinated benzene molecules. The crystal
packing forces influence dramatic second-order Jahn−Teller distortions, making each of the two ((bz)CuCl3)2-
units distinct. These interactions further result in ligand-to-metal and metal-to-ligand charge transfers that cause
an activation of the benzene ligands.