Synthesis And Antimicrobial Study of Fe (II) Complex of Schiff Base Derived From 4- Acyl Antipyrine and Substituted Aniline

The incidence of drug- resistant microbial infections is a growing concern worldwide, necessitating the development of novel antimicrobial agents that would break barrier of resistance, guarantee safety and potency of pharmaceutical products. The chemical synthesis and antimicrobial studies of Iron (II) complexes of Schiff base derived from acetyl chloride antipyrine (4-acyl antipyrine) were carried out using substituted aniline (2- hydroxylaniline) was one such attempts of development of new molecular compounds capable of breaking barrier of resistance. The primary ligand, Schiff base ligand and their metal complex was characterized using spectroscopic techniques ranging from IR, UV-Vis, GCMS. The melting point, molar conductivity, elemental composition was determined. Interestingly, all the synthesized compounds were obtained in good yield (76%-86%). The molecular ion peaks (M+) indicating the molecular weight of the synthesized ligand and metal complex were detected using the various fragments produced by the ligands and metal complexes based on their mass to charge ratio obtained from GC-MS Spectra. Octahedral geometry was observed for Fe (II) complex. The IR absorption showed characteristic behaviour in the sense that the v(C=N) found in SLOA and the metal complexes with frequency range of (1,582.90cm-1) indicate that imine group/Schiff base is formed. The absorption band assigned to C=O in the ligand and metal complexes are as follow 1,700.65cm-1 and 1,623.00cm-1 respectively. The Schiff base ligands SLOA (I,700.65cm-1) showed a notable shift to higher wavenumbers indicating increase C=O bond strength due to coordination with metal through its oxygen or electron withdrawal in the Schiff base framework. Metal complexes show C=O stretching shifted back to lower frequency value (1.633.54cm-1) suggesting co-ordination of oxygen to metal. The metal complexes demonstrated great antimicrobial efficiency on test organisms of both bacteria (Salmonella typhi, Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes) and fungi (Candida albicans) more than the ligand due to lipophilicity of the chelated complexes which retarded their growth process. This study showed that synthesis and complexation have taken place and the knowledge gained will help to advance the course of bioinorganic and inorganic chemistry as well as incorporating ligands and metal complexes into antibiotic drugs production.

Schiff base, Antimicrobial, Metal complex, 4-acyl antipyrine, Fe(II)Complex, Coordination.

1. Sherif E.A.A. and Eldebss T.M. (2011). Synthesis, spectral characterization, solution equilibria, In vitro antibacterial and cytotoxic activities of Cu(II), Ni(II), Mn(II), Co(II) and Zn(II) complexes with Schiff base derived from 5-bromosalicylaldehyde and 2-aminomethylthiophene. Spectrochimica Acta Part A: Molecular and biomolecular spectroscopy 79: 1803-1814. [Google Scholar] [Crossref]

2. Reddy P.R, and Rao K.S. (2006). Ternary nickel(II) complexes as hydrolytic DNA-cleavage agents. Chem Biodivers 3(2): 231-244. [Google Scholar] [Crossref]

3. Saleh, H.S; Dagne A.K; Endalkachew, A.M; Bekele A. (2021) Synthesis, Characterization and Antibacterial Activity Evaluation of 4-amino Antipyrine Derivatives and Their Transition Metal Complexes. American Journal of Bioscience and Bioengineering; 9(1): 8-12 http://www.sciencepublishinggroup.com/j/bio. [Google Scholar] [Crossref]

4. Ralph, L. S; Christine K.F; Hermann, T. C; Morrill, D.Y.C and Reynold C.F. (2009). The Systematic Identification of Organic Compounds. 8th edition, J. Wiley, Hoboken. [Google Scholar] [Crossref]

5. Hartwig J.F (2010), Organometallic Metal Chemistry, from Bonding to Catalysis, University Sciences Books: New York. 1st Edition. [Google Scholar] [Crossref]

6. Okolo A.J., Ezenweke L.O., Emmanuel I.V., Osuagwu C.C., Usiakpebru A.E (2022) Synthesis of Acetyl Resorcinol and Investigation of the Anti-Microbial Potentials of Some of its Metal Complexes. International Journal of Research and Innovation in Applied Science (IJRIAS) |Volume VII, Issue VI, Pg 59-63|ISSN 2454-6194. [Google Scholar] [Crossref]

7. Kay S., Walther B., Peter K., Kettenbach G., Peter M., Dieter K. and Saran, D. (2000). Cellulose Solutions in Water Containing Metal Complexes, Macromolecules, 33, 4094-4107. [Google Scholar] [Crossref]

8. Caruso F, Rossi.M, Tanski.J, Sartori. R, Sariego .R, Moya S,, Diez. S, Navarrete. E, Cingolani. A, Marchetti. F, Pettinari .C, (2000) J. Med. Chem 43 3665. [Google Scholar] [Crossref]

9. Kees K.L, Fitzgerald Jr J.J., Steiner K.E, Mattes. J. F, Mihan.B, Tosi .T, Mondoro .D, McCaleb M.L, (1996) New potent antihyperglycemic agents in db/db mice: synthesis and structure activity relationship (4-substituted benzyl) (trifluoromethylpyrazoles and pyrazolone) J. Med. Chem. 39, 3920-8. [Google Scholar] [Crossref]

10. Jung, J.C., Watkins, E.B., Avery, M.A., (2002) Synthesis of 3- substituted and 3,4-disubstituted pyrazolin-5-ones. Tetrahedron 58, 3639-3646. [Google Scholar] [Crossref]

11. Kimata, A., Nakagawn, H., Ohyama, R., Fukuuchi, T., Ohatsa, S., Suzuki, T; Miyata, N., (2007) New series of antiprion compound: pyrazolone derivatives have the potent activity of inhibiting protease-resistant prion protein accumulation. J. med. chem. 50, 5053-5056. [Google Scholar] [Crossref]

12. Bojan, B., Marijan, K., Slovenko, P., (2009) A simple approach to pyrazol-3-ones via diazenes. Tetrahedron 65, 8690-8696. [Google Scholar] [Crossref]

13. Gursory, A., Demirayak, S., Capan, G., Erol, K., Vural, K., (2000) Synthesis and preliminary evaluation of new 5-pyrazolinone derivatives as analgesic agents. Eur. J. Med. Chem. 35, 359-364. 19. [Google Scholar] [Crossref]

14. Godoy, M.C., Fighera, M.R., Souza, F.R., Flores, A.E., Rubin, M.A., Oliveira, M.R., (2004) Alpha 2-adrenocepters and 5-HT receptors mediate the antinociceptive effect of the new pyrazolines, but not of dipyrone. Eur. J. Pharmacol. 496 (1-3), 93-97. 25. [Google Scholar] [Crossref]

15. Chiba, P., Holzer, W., Landua, M., Bachmann, G., (1998) Substituted 4-Acylpyrazoles and 4-Acylpyrazolones: synthesis and multidrug resistance-modulating activity. J. Med. Chem. 4, 4001-4011. [Google Scholar] [Crossref]

16. Bertsch U; Winklhofer K.F; Hirschberger T; Bieschke J; Weber P; Hartl F.U; Tavan P; Tatzelt.J; Kretzchmar H.A; Giese A (2005). Systematic identification of Antiprion Drugs by High- Throughput Screening Based on Scanning for intensely Fluorescent Target. Journal of Virology. 79(12):7785-7791. [Google Scholar] [Crossref]

17. Mercer R.C and Harris D.A (2019). Identification of anti-prion drugs and targets using toxicity-based assays. Pharmacology; 44:20-27. [Google Scholar] [Crossref]

18. Shemarova I.V., Maizel, E.B., Voznyi, I.V., Stepanova, N.P., Khovanskikh, A.E., (2000). Synthesis of new derivatives of pyrazolone and nicotinic acid and study of their effect on cytochrome P450. Activity Pharm. Chem. J. 34 (10), 530-532. [Google Scholar] [Crossref]

19. Shyamala-Donge B.S., Sisay G.(2011) Synthesis and Characterization of some transition metal complexes with O,N,O and O,O donor ligands. AAU Institutional Repository.5(2):14-62. [Google Scholar] [Crossref]

20. Varshney, V., Gupta, M., Bansal, K.B. and Nershney, A.K. (2013). Synthesis, characterization, antimicrobial and insecticidal activity of some new ruthenium (iii) complexes with Schiff bases of amino acids. Indian Journal of Inorganic Chemistry, 8(5): 129 – 135. [Google Scholar] [Crossref]

21. Hossian, S., Zakaria, C.M., E-Zahan, K. and Zaman, B. (2017). Synthesis, spectral and thermal characterization of Cu(ii) complexes with two new Schiff base ligands toward potential biological applications. Der Chemica sinica, 8(3): 380 – 392. [Google Scholar] [Crossref]

22. Ochie O.S., Okonkwo S.I. P. O. Okwuego (2025) Synthesis and Characterization of Nanostructured Sorbents Derived from Rice Husks using FTIR, SEM, TEM and XRD Approaches. International Research Journal of Pure and Applied ChemistryVolume 26, Issue 1, Page 38-48, Article no. IRJPAC.129516ISSN: 2231-3443, NLM ID: 101647669 [Google Scholar] [Crossref]

23. Okonkwo S.1, Ughanze B.N, Okonkwo C.K, Ezigbo V.O, Okafor, E.C , Okwuego P.O, Okonkwo A.T, Okonkwo V. S.(2025) Determination of the Chemical and Morphological Structure of Liposomes Encapsulating Lycopene Derived from Tomatoes Using FTIR, SEM, TEM, and Ultrasound Imaging Techniques Volume 03 | Issue 04 | Article Id IJPS/250304235 [Google Scholar] [Crossref]

24. korie E.A, Offiah V, O, Oragwu P.I, Okwuego P.O (2025) Assessment of Heavy Metals and Polycyclic Aromatic Hydrocarbons in Soil and Water in Selected Mining Areas of Ebonyi State, Nigeria. Journal of Global Ecology and Enviroment. Doi: 10.56557/jogee/v21i29123 [Google Scholar] [Crossref]

25. Okwuego P. O (2022) Oil Removal by Structured Natural Sorbents Made from Pumpkin Stem Fibres. COOU Journal of Physical Sciences (6)1 https://cjps.coou.edu.ng/ [Google Scholar] [Crossref]

26. Okwuego P. O, (2023) Optimization of oil spill cleanup using composites fibres (ES) modified kola nut pod. International Journal of Chemistry and Chemical Processes E-ISSN 2545-5265 P-ISSN 2695-1916, Vol 9. No.4 www.iiardpub.org [Google Scholar] [Crossref]

27. Okwuego P. O, Okafor E.C, Okolo A.J, Anyanwu C.G (2025) Comparative Study of Engineered Bio-Sorbents Derived from Agricultural Waste. International Journal of Research and Innovation in Applied Science (IJRIIAS) ISSN NO. 2454-6194 doi.org/10.51584/IJRIAS Vol. 5. Issue 4 [Google Scholar] [Crossref]

28. Okwuego P.O (2023.) Oil Removal by Structural Natural Sorbent made from PumpkinStemFibres Chukwuemeka Odumegwu Ojukwu University COOU Journal of Physical Sciences, Vol.6, Number 1, [Google Scholar] [Crossref]

29. Okwuego P.O, Chigbo, A. I, Okpala F.,Oragwu I.P and Omoh T.O (2025) Spectral Characterization of Polyvinyl Acetate and It's Modified Mercury Complex, Exploring It's Structure and Application. Research Journal of Pure Science and Technology E-ISSN 2579-0536 P-1SSN 2695-2696Volume 8, No 6 www.iiardpub.org [Google Scholar] [Crossref]

30. Okwuego P.O, Okonkwo S.I, Ekwonu A.M, (2021) Analysis of Structured natural sorbent from agricultural waste materials. International Journal of Chemistry and Chemical Processes E-ISSN 2545-5265 P-ISSN 2695-1916, Vol 7. No. 1 www.iiardpub. org [Google Scholar] [Crossref]

31. Okwuego, P.O, Offiah V.O, Nkachukwu, M.B, Ifeakor, C.O. (2025) Comprehensive Analysis of Leachables and Extractables from Pharmaceutical Packaging: Investigating Ink and Adhesive Migration in Selected Drug Products in Nigeria International Journal Of Research And Innovation In Applied Science (IJRIIAS) ISSN NO. 2454-6194 DOI: https://doi.org/10.51584/IJRIASs.10040007 [Google Scholar] [Crossref]

32. Oragwu I.P, Okolo. A.J, Okwuego P.O, Ntokah. K. .(2024) Characterization of Some Local [Google Scholar] [Crossref]

33. Clay Minerals and Fabrication into Ceramic Floor-Tiles American Journal of Polymer Science [Google Scholar] [Crossref]

34. and Technology DOI: 10.11648/j.ajpst Vol. 10. Issue 4 ISSN 2575-5986 [Google Scholar] [Crossref]

35. Oragwu, I.P., Nwankpa, C., Okolo, A.J., Okafor, C.E. (2024). Comparative Studies on Alkyd [Google Scholar] [Crossref]

36. Resins from Palm (Elaeis guineensis) Oil and Mango (Mangifera) Seed-Oil. Open Journal of [Google Scholar] [Crossref]

37. Polymer Chemistry, 14, 199-213. https://doi.org/10.4236/ojpchem.2024.144009 [Google Scholar] [Crossref]

38. Victor E.I, Onuh E.F, Alfred N.O, Omozefe O.E, Okolo A.J, Chukwufumnanya M.J (2022). Synthesis and fastness properties of disperse dyes gotten from some aniline derivatives. DISCOVERY; 58(324):1408-1414. [Google Scholar] [Crossref]

39. Friday E.O, Victor E.I, Alfred N.O, Okoro L.N, Agboola B.O, Muhammadu Y, Okolo A.J, Silvester U.N, Omozefe O.E, Chukwufumnaya M.J, Ndulaka J.C, Chima C.H, Roseline O.C(2022). Synthesis, spectroscopic studies and fastness evaluation of disperse dyes derived from aniline derivatives on polyester fabric. DISCOVERY; 58(324):1309-1316. [Google Scholar] [Crossref]

40. Obi J.C., Emmanuel V.I., Okolo A.J., Onuh E.F., Osuagwu C.C., Okorocha N.J., Olisa N.A., Okechukwu O.J (2022). Synthesis of Monoazo Dye from Halogenated Arylamines and Fastness Properties on Cotton and Nylon. Multidisciplinary Journal for Applied Research in Engineering and Technology (MJARET) 2(2): 17-22 [Google Scholar] [Crossref]

41. Oragwu I.P., Okolo A.J., Okwuego P.O., Okafor C.E. (2025). Synthesis of Palm Oil- Modified Polyester (Alkyd Resin). International Journal of Latest Technology in Engineering, Management & Applied Science (IJLTEMS). 14(9): 123-130. DOI: 10.51583/IJLTEMAS. ISSN 2278-2540 [Google Scholar] [Crossref]

42. Okolo A.J, Ossai E.K, Emmanuel I.V, Osuagwu C.C., Usiakpebru A.E (2022). Concentrations of Selected Heavy metals (Iron, Manganese, Cadmium, Lead, Chromium, and Nickel) in three fish species from Ase River at Kwale, Delta State, Nigeria. International Journal of Research and Innovation in Applied Science (IJRIAS) 7(3):21-25 [Google Scholar] [Crossref]

43. Oragwu I.P., Okolo A. J., Emmanuel I.V., Okoli P.O., Osuagwu C.C., Onyia O.E., Usiakpebru A. A., Okechukwu J.O (2021). Phytochemical and proximate composition of cucumber (Cucumis Sativus) Seed oil. International Journal of Research and Scientific Innovation (IJSRI) 7(2) :224-250. www.rsisinternational.org. [Google Scholar] [Crossref]

• Green Synthesis of Cobalt Oxide/Gold (Coo/Au) Bimetallic Nanoparticles Using Sinapinic Acid: A Comprehensive Study
• Advances in Solar Cell Technologies: A Comprehensive Review of Material Synthesis, Structural Properties, Efficiency and Diverse Applications
• Thermal Decomposition of Co-Fe-Cr-Citrate Complex Via Structural and Spectral Study
• Surface Activity and Thermodynamic Assessment of Surfactants Derived from Oreochromis Niloticus Oil (Nile Tilapia Fish)
• Green Synthesis of Robust Metal-Organic Frameworks: A Sustainable Approach for Advanced Applications