Thiophene-Derived Schiff Base Complexes: Synthesis, Characterization, Antimicrobial Properties, and Molecular Docking

Area of Science:

• Coordination Chemistry
• Medicinal Chemistry
• Materials Science

Background:

• Schiff base ligands derived from thiophene are explored for their coordination properties.
• Metal complexes often exhibit enhanced biological activities compared to their parent ligands.

Purpose of the Study:

• To synthesize and characterize a novel thiophene-derived Schiff base ligand (DE) and its metal(II) complexes.
• To evaluate the in vitro antimicrobial potential of the ligand and its metal complexes against a range of pathogens.
• To investigate the structural and electronic properties influencing the observed biological activities.

Main Methods:

• Synthesis of Schiff base ligand (E)-N¹,N¹-diethyl-N²-(thiophen-2-ylmethylene)ethane-1,2-diamine (DE).
• Preparation and structural characterization of M(II) complexes [M(DE)X] (M = Cu, Zn, Cd; X = Cl, Br) using X-ray diffraction.
• In vitro antimicrobial screening against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Leishmania major.
• Molecular docking studies to support experimental findings.

Main Results:

• The crystal structure of [Zn(DE)Cl] and [Cd(DE)Br] revealed distorted tetrahedral geometries.
• All synthesized metal complexes displayed significant in vitro antimicrobial activity.
• The complexes were more potent antimicrobials than the free ligand DE.
• [Cd(DE)Br] showed the most promising activity against all tested microbes.

Conclusions:

• The novel thiophene-derived Schiff base ligand and its metal complexes possess significant antimicrobial properties.
• Metal complexation enhances the antimicrobial efficacy of the Schiff base ligand.
• The [Cd(DE)Br] complex is a potential candidate for developing new antimicrobial agents against diverse infections.