Experimental and quantum chemical studies of sulfamethazine complexes with Ni(II) and Cu(II) ions

Abstract

[Ni(SZ)Cl(H₂O)₃]·2H₂O and [Cu(SZ)(NO₃)(H₂O)₂]·2H₂O (HSZ = 4-amino-N-(4,6-dimethyl-2-pyrimidinyl)benzenesulfonamide, sulfamethazine) have been synthesized and characterized by experimental and theoretical methods at the DFT/B3LYP/LANL2DZ level of theory. Ni(II) is coordinated by sulfonamidic (N15) and pyrimidic (N23) of the sulfamethazine drug, three water molecules, and one chloride forming a distorted octahedral geometry, while the Cu(II) complex has a square pyramidal geometry with the same ligand N,N active binding sites. Natural bond orbital (NBO) analysis of CuSZ reveals the participation of the coordinated in triple H-bonds of different strengths with hydrated water molecules, LP(2)O33 → σ^∗(O45–H46), LP(2)O40 → σ^∗(O45–H44), and LP(2)O38 → σ^∗(O48–H47). The voltammogram of NiSZ shows one cathodic and one anodic peak. The complexes and NaSZ were screened for their antibacterial activity.

Keywords:

• Sulfamethazine
• Antimicrobial
• LANL2DZ
• TD-DFT
• Electrochemical