Crystal structure and magnetic studies of bis(mu-dibutylphosphinato) copper (II)

The structure of Cu(OP(C4H9)2O)2 in the solid state has been determined by three-dimensional single-crystal X-ray techniques. The structure was solved by the heavy-atom technique, and least squares refinement gave an R factor of 0.061. The structure consists of polymeric chains of copper atoms linked by double phosphinate bridges. The coordination around each copper atom can be described as a very flattened tetrahedron. The g tensors for oriented single crystals were determined by ESR and range from 2.07 to 2.41, with the larger value in a direction nearly normal to a mean plane formed by the copper atoms and the ligands. The spin orbit coupling constant suggests considerable mixing of metal and ligand orbitals in this polymer.