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)(H(2)O)]H(2)O}(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 mu-carboxyl group. The mu-carboxyl exobidentate bridging coordination mode leads to a one-dimensional chain structure. The ZnN(2)O(3)O' chromophore has an elongated pseudo-octahedral geometry (1), whereas the CuN(2)O(2)O' (2) chromophore presents a distorted square-pyramidal environment with tau = 0.19 around the Cu(2+) ion. (C) 2009 Elsevier Ltd. All rights reserved.