Benzene-copper(I) coordination in a bimetallic chain complex

The solvothermal reaction of CuCl and ZrCl4 in benzene yields ((bz)CuCl3)(2)Zr (1) (bz = eta(2)-benzene), which has been characterized by single-crystal X-ray diffraction with a = 6.1206(4) Angstrom, b = 11.1242(4) Angstrom, c = 13.6222(6) Angstrom, beta = 93.675(3)degrees in the monoclinic space group P2(1)/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 pi-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.