To a methanolic solution (5 mL) of copper acetate salt (0.50
mmole), a methanolic solution of the bioactive HL2 sulfonamide ligand
(sulfamerazine, 1.26 mmole) was added at room temperature.
After 3 min of stirring, a concentrated solution of NH3 (25% volume)
was added drop wise until the apparition of an intense blue color
characteristic of the presence of the [Cu(NH3)6]2+ complex. After
few days, the solution color turned to green and single-crystal for
X-ray characterizations were obtained by slow evaporation of the
solvent.