[H₂NMe₂]CuZrCl₆:  Hydrogen-Bond Induced Distortions in a Copper Zirconium Chloride Analogue of a Thiophosphate

The copper(I) zirconium(IV) halide, [H 2 NMe 2 ]CuZrCl 6 ( 1 ), has been synthesized, and its single-crystal X-ray structure was determined. The crystal undergoes a phase transition at −60 °C giving a room-temperature structure with a = 10.1105(6) Å, b = 9.9463(5) Å, c = 12.7254(8) Å, β = 110.287(5)° in the monoclinic space group C 2/ c, Z = 4, and a low-temperature structure (−116 °C) with a = 10.234(2) Å, b = 9.427(1) Å, c = 12.691(2) Å, β = 109.90(2)° in the monoclinic space group P 2 1 / c, Z = 4. [H 2 NMe 2 ]CuZrCl 6 is constructed from unique one-dimensional chains with zirconium and copper in alternating octahedral and tetrahedral coordination environments, respectively. The structural relationship between (CuCl 4 ) 3 - and (PS 4 ) 3 - is demonstrated by the analogy of this structure to that of KNiPS 4 . The phase transition, which occurs at approximately −60 °C, results in altered configurations of the dimethylammonium to metal−chloride hydrogen bonding. In addition, a remarkable distortion in the cuprous chloride tetrahedral unit is observed in the room-temperature structure, whereas the zirconium chloride octahedron is distorted in the low-temperature crystal structure. These distortions are discussed in terms of hydrogen-bond driven second-order Jahn−Teller-type distortions.