Synthesis, structure and properties of [Zn(L-Tyr)₂(bpy)]₂⋅3H₂O·CH₃OH complex: theoretical, spectroscopic and microbiological studies.

The mixed ligand zinc(II) ion complex of the formula [Zn(l-Tyr)(2)(bpy)](2)·3H(2)O·CH(3)OH (1), where L-Tyr and bpy are moieties of L-tyrosine and 2,2'-bipyridine (2,2'-bpy), has been isolated in a crystalline form. Crystal structure was determined and the spectroscopic (FTIR, Raman and near IR (NIR)-visible (vis)-UV) examinations were conducted. Additionally, the theoretical data of the molecular structure were obtained using the density functional theory (DFT) methods. Crystals of complex 1 adopt hexagonal form with a=b=12.9307 (18)Å, c=30.148 (6)Å and γ=120 lattice parameters, and P3(2)2(1) space group. The crystal structure is built of [Zn(L-Tyr)(2)(bpy)] units and disordered solvent molecules of water and methanol. Each L-tyrosine chelates the zinc(II) ion via carboxylate oxygen and amino nitrogen atoms. The donor atoms form the cis-[ZnN(2)N(2)'O(2)] chromophore with the distorted octahedral geometry around the Zn(2+) ion. Complex 1 as well as [Zn(Im)(L-Tyr)(2)](2)·5H(2)O (2) and {[Zn(L-Tyr)(2)(H(2)O)]·H(2)O}(n) (3) compounds were examined as potential inhibitors of the growth of plant and animal fungi, such as Fusarium solani, Penicillum verrucosum, Aspergillus flavus, and bacterial strains, such as Gram-negative Escherichia coli, Pseudomonas fluorescens, Serratia marcescens and Gram-positive Bacillus subtilis.