Synthesis, Spectroscopic Characterization, and Antibacterial Evaluation of Novel Organophosphorus Schiff Base Derivatives Derived from Chlorodiphenylphosphine

In this study, three novel organophosphorus Schiff base derivatives (OPC1–OPC3) were successfully synthesized by condensing chlorodiphenylphosphine with different Schiff bases derived from various aldehydes and hydrazine derivatives. The structural elucidation of the synthesized compounds was achieved using comprehensive spectroscopic analyses, including FTIR, UV-Vis, and both 1H and 13C NMR spectroscopy. Elemental analysis and physical property measurements further confirmed the proposed molecular structures. Spectroscopic data revealed characteristic azomethine (C=N), phosphorus–carbon (P–C), and phosphorus oxygen (P–O–C) stretching bands, confirming the successful formation of the organophosphorus Schiff base framework. The synthesized compounds were tested for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using the agar well diffusion method. The results demonstrated that all compounds exhibited moderate to significant antibacterial activity, with OPC2 and OPC3 showing notable inhibition zones compared to OPC1. These findings suggest that the incorporation of organophosphorus moieties into Schiff base ligands enhances their biological potency and provides a promising route for developing new bioactive organophosphorus materials.