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

A novel zinc(II) polymeric complex of the formula {[Zn(tyr)2(H2O)]H2O}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 ZnN2O3O′ chromophore has an elongated pseudo-octahedral geometry (1), whereas the CuN2O2O′ (2) chromophore presents a distorted square-pyramidal environment with τ = 0.19 around the Cu2+ ion.

Graphical abstractA one-dimensional coordination polymeric structure exists for {[Zn(tyr)2(H2O)]H2O}n, due to one tyrosine ligand acting as an exobidentate bridging ligand. The coordination polymer is created as an unstranded chain with a trans coordination of the carboxylate groups of l-Tyr(A).Figure optionsDownload full-size imageDownload as PowerPoint slide