Structural characterization and antimicrobial activity of a silver(I) complex of arginine

A silver(I) complex of arginine (arg), [Ag(arg)]NO₃•0.5H₂O (1) was prepared and characterized by elemental analysis, IR and NMR spectroscopy, and X-ray crystallography. The IR and NMR spectroscopic data confirmed the coordination of the ligand to silver(I). The structure of 1 shows that it is polymeric with each silver atom bound to the carboxyl O atom of one arginine ligand and to the amino N atom of another adopting a linear coordination environment. The two coordinate N-Ag-O units are repeated to form infinite chains. The molecular structure is stabilized by N-H...O and C-H...O hydrogen bonds. Antimicrobial activities of the complex were evaluated by minimum inhibitory concentration against gram-negative bacteria (E. coli, P. aeruginosa), molds (A. Niger, P. citrinum) and yeasts (C. albicans, S. cerevisiae).