Synthesis, characterization and crystal structure of a monomeric and a macrocyclic copper (II) complex with a large cavity using benzylacetylacetone ligand

The bidentate ligand benzylacetylacetone was used to synthesize the Cu(II) complexes 1 and 2 without and with 4,4′-bipyridine ligand, respectively. The complexes were characterized by analytical and spectroscopic studies. The mononuclear complex [Cu(C10H9O2)2] (1) has been synthesized by the reaction of copper acetate with the ligand whereas the tetranuclear complex [Cu4(4,4′-bpy)4(C10H9O2)4(C2H3O2)4] (2) has been synthesized by the reaction of copper acetate with the ligand followed by the addition of 4,4′-bipyridine. The X-ray analysis shows that the complex 1 has square planar geometry and the complex 2 has square pyramidal geometry around the metal centers. The thermogravimetric studies showed that the complexes undergo decomposition in multiple steps.