Silver (I)- Schiff-base complex intercalated layered double hydroxide with antimicrobial activity

In this work, silver nitrate complexes of sulfanilamide-5-methyl-2-thiophene carboxaldehyde (SMTCA) ligand intercalated Zn/Al-layered double hydroxide [Ag-SMTCA-LDH] were synthesized for the potential application as an antimicrobial system. The SMTCA ligand was synthesized by reacting sulfanilamide and 5-methyl-2-thiophene carboxaldehyde in methanol and further complexation with silver nitrate metal ions [Ag-SMTCA]. The structural analyses of synthesized compounds confirmed an intercalation of Ag-SMTCA into Zn/Al-NO₃-LDH by flake/restacking method. SMTCA, Ag-SMTCA and Ag-SMTCA-LDH were characterized by ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, Fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). It was found that Ag-SMTCA-LDH exhibited good antimicrobial activity against both gram-positive (<i>Bacillus subtilis</i>, [<i>B. subtilis</i>], <i>Staphylococcus aures</i>, [<i>S. aureus</i>]) and gram-negative (<i>Escherichia coli</i>, [<i>E. coli</i>], <i>Pseudomonas aeruginosa</i> [<i>P. aeroginosa</i>]) bacteria as well as excellent antioxidant activity.