Synthesis, structure, and magnetic properties of bis(monosubstituted-pyrazine)dihalocopper(ii)

The investigation into synthesizing new metal organic compounds with the general formula Cu(S-pyrazine)X(2) using monosubstituted pyrazines has led to the generation of a new family of compounds Cu(S-pyrazine)(2)X(2) with similar structure and magnetic properties. The bis(S-pyrazine)dihalocopper(II) compounds [where S = Cl, CN, OCH(3), and OCH(2)CH(3) and halide = Cl or Br] have been characterized by IR, powder X-ray diffraction, single-crystal X-ray diffraction, and temperature dependent magnetic susceptibility. The bis(chloropyrazine)dihalocopper(II) compounds crystallize in the monoclinic space group P2(1)/n while the methoxy and ethoxy analogues crystallize in the triclinic space group P1. This structurally related family of compounds exhibit antiferromagnetic interactions with exchange constants of approximately -25 K for the chloride analogues and -50 K for the bromide analogues.