Polymeric Zn(II) and Cu(II) complexes with exobidentate bridging l-tyrosine: Synthesis, structural and spectroscopic properties

Abstract

A novel zinc(II) polymeric complex of the formula {[Zn(tyr) 2(H 2O)]H 2O} n ( 1) containing l-tyrosine (tyr) was prepared in the crystalline form and characterized by X-ray diffraction, NIR–Vis–UV electronic and IR–FIR vibrational spectroscopy methods. Additionally, for the [Cu(tyr) 2] n ( 2) polymer, the vibrational, electronic, EPR spectroscopic and magnetic properties were studied. l-tyrosine in coordination polymers acts as a N,O-bidendate ligand and presents exobidentate bridging with a μ-carboxyl group. The μ-carboxyl exobidentate bridging coordination mode leads to a one-dimensional chain structure. The ZnN 2O 3O′ chromophore has an elongated pseudo-octahedral geometry ( 1), whereas the CuN 2O 2O′ ( 2) chromophore presents a distorted square-pyramidal environment with τ = 0.19 around the Cu 2+ ion.