Pathway from chain to dimer in Cu(I) camphor hydrazone complexes

The chemical reactivity, molecular structure, and surface characteristics of Cu(I) camphor hydrazone compounds indicate that exist a structural pathway for conversion of coordination polymers into dimers and vice versa. By X-ray diffraction analysis two polymorphic forms of the chain compound {CuCl}(2)(Me(2)NNC(10)H(14)O)](n) were identified that essentially differ in the structural arrangement and geometry of the non-linear copper atom. The characterization of the dimer complexes {Cu(Me(2)NNC(10)H(14)O)}(2)(μ-X)(2)] (X = Cl or Br) was also achieved by X-ray diffraction analysis showing the unusual arrangement of the camphor hydrazone ligands that occupy the same side of the molecule. Bond lengths and torsion angles show that one of the polymorphic forms is structurally close to the related dimer. The surface composition of the coordination polymers {CuX}(2)(YNC(10)H(14)O)](n) (X = Cl, Y = NMe(2), NH(2); X = Br, Y = NH(2)) and dimers {Cu(Me(2)NNC(10)H(14)O)}(2)(μ-X)(2)] (X = Cl or Br) studied by X-ray Photoelectron Spectroscopy corroborate the molecular properties and the reactivity trend.