Scheme 1. Structural representation27 of the Cu(ii) complexes Cu-3G and Cu-2GH of the present study. Open rectangles represent sites of water coordination. Ligands are H-Gly-Dap(H-Gly)-Gly-NH₂ (3G) and H-Gly-Dap(H-Gly)-His-NH₂ (2GH). Potential H-bonding sites are marked with red and blue.