TITLE:
Synthesis, Structural Characterization, and Comparative Biological Study of Three New Schiff Bases Derived from Diamines
AUTHORS:
Kangah Niameke Jean Baptiste, Tuo Nanou Tiéba, Zialé Djélé Alette Edwige, Kodjo Charles Guillaume, Ziao Nahosse
KEYWORDS:
Schiff Base, Spectrometry, Antibacterial Activity, Antioxidant Activity
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.16 No.2,
May
30,
2026
ABSTRACT: This paper focuses on the synthesis, structural characterization, and biological activity evaluation of three new Schiff bases: N,N'-bis(4-nitrophenylmethylene)benzene-1,3-diamine (compound 4-BD), N,N'-bis(4-nitrophenylmethylene)cyclohexane-1,2-diamine (compound 4-CD), and N,N'-bis(4-nitrophénylméthylène)hexane-1,6-diamine (compound 4-HD). They were obtained respectively by condensation reaction of metaphenylenediamine, cyclohexane-1,2-diamine, and hexane-1,6-diamine with 4-nitrobenzaldehyde. The structural characterization of these compounds was carried out using standard spectroscopy techniques such as 1H and 13C NMR, infrared spectroscopy (IR), and mass spectrometry, which confirmed the expected structures. Biological activity evaluation through antimicrobial and antioxidant tests showed that compound 4-BD possesses significant antibacterial activity against Staphylococcus aureus (MIC of 48.87 (µg/mL)), moderate activity against S. aureus sensible, but remains inactive against Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. It also shows significant antioxidant activity (71.559), much more pronounced than its tested structural homologs. Indeed, compound 4-CD possesses an antibacterial activity of 187.5 µg/mL and an inhibition capacity of 15.521. Regarding compound 4-HD, we have an antibacterial activity of 375 µg/mL and an antiradical activity of 14.507. These observations highlight the importance of the presence of a central aromatic group in this specific case for the biological properties of Schiff bases. Opportunities are emerging for the synthesis of a wider range of analogous compounds, to better understand structure-activity relationships and to optimize their pharmacological applications.