Abstract
A new Schiff base, 2-((benzo[d]thiazol-2-ylimino)methyl)phenol (L1), was synthesized via condensation of 2-hydroxybenzaldehyde with 2-aminobenzothiazole. Complexes of L1 with Co(II), Ni(II), Cu(II), and Zn(II) were prepared and characterized using various techniques, including elemental analysis (CHNS), infrared (FTIR), UV-visible (UV-Vis) and nuclear magnetic resonance (1H, 13C NMR) spectroscopies, thermogravimetric analysis (TGA), magnetic susceptibility, atomic absorption (AAS), molar conductivity, and melting point. The results suggested an octahedral geometry for the complexes and a 1:2 electrolytic nature. The biological activity of the ligand and its complexes was tested, and significant antibacterial activity against selected bacterial strains was observed.
References
Abd El-Lateef, H. M.; Ali, A. M.; Khalaf, M. M.; Abdou, A. New iron (III), cobalt (II), nickel (II), copper (II), zinc (II) mixed-ligand complexes: Synthesis, structural, DFT, molecular docking and antimicrobial analysis. Bulletin of the Chemical Society of Ethiopia. 2024, 38 (1), 147–166. https://doi.org/10.4314/bcse.v38i1.12
Abed, R. R.; Ahmed, F. J.; Raoof, S. A. New Cu (II) and Zn (II) complexes with O-nitrobenzylidene trimethoprim, Evaluation of their Antibacterial activities. Proceedings of the 1st International Multi-Disciplinary Conference Theme: Sustainable Development and Smart Planning, IMDC-SDSP 2020, Cyperspace, 28-30 June 2020. https://doi.org/10.4108/eai.28-6-2020.2298121
Abed, R. R.; Mohammed, A. S.; Ahmed, F. J. Synthesis and diagnoses of new metal ions complexes derived from trimethoprim schiff bases. Research Journal of Pharmacy and Technology. 2021, 14 (9), 4963–4968. https://doi.org/10.52711/0974-360X.2021.00863
Abousaty, A. I.; Reda, F. M.; Hassanin, W. A.; Felifel, W. M.; El-Shwiniy, W. H.; Selim, H. M.; Bendary, M. M. Sorbate metal complexes as newer antibacterial, antibiofilm, and anticancer compounds. BMC microbiology. 2024, 24 (1), 262. https://doi.org/10.1186/s12866-024-03370-w
Adnan, T. K.; Ahmed, K. Y.; Jarullah, A. A. Synthesis and application of new Co/Cu/Ni/Zn (II) Schiff base complexes in the biological activity and oxidation of alcohols. Iranian Journal of Catalysis. 2024, 14 (3), 142426. https://doi.org/10.57647/j.ijc.2024.1403.26
Afifi, M. A.; Rasmy, A. A.; Elzayat, E. M.; El-Medani, S. M.; Shehata, M. R.; Elantabli, F. M. Spectroscopic, docking, antiproliferative, and anticancer activity of novel metal derivatives of phenylacetohydrazide Schiff base on different human cancer cell lines. BMC Chem. 2025, 19 (1), 69. https://doi.org/10.1186/s13065-025-01417-1
Ahmed, F. J.; AbdAlqader, B.; Haddad, R. A.; Abed, R. R.; Saleh, M. Y. Preparation and diagnosis of Zn (II), Cd (II) and Hg (II) complexes with Schiff base ligand derived from trimethoprim. Egyptian Journal of Chemistry. 2022, 65 (10), 359–366. https://doi.org/10.21608/EJCHEM.2022.119210.5362
Alkam, H. H. Synthesis and Characterization of New Bidentate Schiff Base Ligand Type (NO) Donor Atoms Derived from Isatin and 3-Amino Benzoic Acid and Its Complexes with Co (II), Cu (II), Cd (II) and Hg (II) Ions. Ibn AL-Haitham Journal For Pure and Applied Science. 2017, 30 (3), 158–169. https://doi.org/10.30526/30.3.1610
Almáši, M.; Vilková, M.; Bednarčík, J. Synthesis, characterization and spectral properties of novel azo-azomethine-tetracarboxylic Schiff base ligand and its Co (II), Ni (II), Cu (II) and Pd (II) complexes. Inorganica Chimica Acta. 2021, 515, 120064. https://doi.org/10.1016/j.ica.2020.120064
Aziz, T.; Nasim, H. A.; Ahmad, K.; Shah, H.-u.-R.; Parveen, S.; Ahmad, M. M.; Majeed, H.; Galal, A. M.; Rauf, A.; Ashfaq, M. Rational synthesis, biological screening of azo derivatives of chloro-phenylcarbonyl diazenyl hydroxy dipyrimidines/thioxotetrahydropyrimidines and their metal complexes. Heliyon. 2023, 9 (1), e12492. https://doi.org/10.1016/j.heliyon.2022.e12492
Butera, V.; D’Anna, L.; Rubino, S.; Bonsignore, R.; Spinello, A.; Terenzi, A.; Barone, G. How the Metal Ion Affects the 1H NMR Chemical Shift Values of Schiff Base Metal Complexes: Rationalization by DFT Calculations. The Journal of Physical Chemistry A. 2023, 127 (44), 9283–9290. https://doi.org/10.1021/acs.jpca.3c05653
Chavan, J. K.; Patil, R. M. Synthesis, Spectroscopic and Biological Activity Studies of Zinc(II) Complexes of N1, N'4-bis ((1E, 2E)-2-(hydroxyimino)-1-(4-R)-phenylethylidene) terephthalohydrazide Schiff base. Oriental Journal of Chemistry. 2024, 40 (3), 689–697. https://doi.org/10.13005/ojc/400308
Dalia, S. A.; Afsan, F.; Hossain, M. S.; Khan, M. N.; Zakaria, C.; Zahan, M.-E.; Ali, M. A short review on chemistry of schiff base metal complexes and their catalytic application. Int. J. Chem. Stud. 2018, 6 (3), 2859–2867.
Gavali, L. V.; Mohammed, A. A.; Al-Ogaili, M. J.; Gaikwad, S. H.; Kulkarni, M.; Das, R.; Ubale, P. A. Novel terephthalaldehyde bis (thiosemicarbazone) Schiff base ligand and its transition metal complexes as antibacterial Agents: Synthesis, characterization and biological investigations. Results in Chemistry. 2024, 7, 101316. https://doi.org/10.1016/j.rechem.2024.101316
Hamil, A.; El-ajaily, M.; Basher, L.; Miloud, M.; Saad, S. Mixed ligand chelates using Schiff base and 2-aminobenzoic acid as ligands. Libyan Journal of Medical Research. 2024, 18 (1), 1–17. https://doi.org/10.54361/10.26719/llmr18-1.01
Ismail, A. A.; Lateef, S. M. Structural, characterization, and biological activity of novel schiff base ligand derived from pyridoxal with 2-aminobenzothazol and its complexes. Chemical Methodologies. 2022, 6, 1007–1022. https://doi.org/10.22034/chemm.2022.357804.1600
Khalil, E.; Mahmoud, W.; Mohamed, G. Synthesis, spectral, thermal and biological studies of some transition and inner transition Schiff base metal complexes. Egyptian Journal of Chemistry. 2021, 64 (7), 3555–3571.
Khalil, M. H.; Abdullah, F. O. Synthesis, characterisation, and anticancer and antioxidant activities of novel complexes of palladium and an organic Schiff-base ligand. Bulletin of the Chemical Society of Ethiopia. 2024, 38 (3), 605–613. https://doi.org/10.4314/bcse.v38i3.5
Knittl, E. T.; Abou-Hussein, A. A.; Linert, W. Syntheses, characterization, and biological activity of novel mono- and binuclear transition metal complexes with a hydrazone Schiff base derived from a coumarin derivative and oxalyldihydrazine. Monatsh Chem. 2018, 149 (2), 431–443. https://doi.org/10.1007/s00706-017-2075-9
Mansour, M.; Abd-Elkarim, A. T.; Mahmoud, W. H.; El-Sherif, A. A. Quinazoline-Glycine Manganese (II) Nano-Complex for Arsenic Sensing via QCM: Synthesis, Characterization, DFT Studies, Biological Evaluation and Environmental Application. Egyptian Journal of Chemistry. 2024. https://doi.org/10.21608/ejchem.2024.294794.9796
Mohamed, E. A.; Ali, A. E.; Kolkaila, S. A.; Fyala, S. S.; Elasala, G. S. Synthesis, Spectroscopic Studies, Thermal Analysis and Molecular Docking of Chloramphenicol Metal Complexes as Anti-Prostate Cancer. TWIST. 2024, 19 (1), 400–408.
Mukhtar, S. S.; Hassan, A. S.; Morsy, N. M.; Hafez, T. S.; Hassaneen, H. M.; Saleh, F. M. Overview on synthesis, reactions, applications, and biological activities of Schiff bases. Egyptian Journal of Chemistry. 2021, 64 (11), 6541–6554.
Oladipo, S. D.; Luckay, R. C. Copper (II) complexes derived from naphthalene-based halogenated Schiff bases: Synthesis, structural analysis, DFT computational studies and in vitro biological activities. New Journal of Chemistry. 2024, 48 (30), 13276–13288. https://doi.org/10.1039/D4NJ01621A
Ommenya, F.; Nyawade, E.; Andala, D.; Kinyua, J. Synthesis, Characterization and Antibacterial Activity of Schiff Base, 4‐Chloro‐2‐{(E)‐[(4‐Fluorophenyl) imino] methyl} phenol Metal (II) Complexes. Journal of Chemistry. 2020, 2020 (1), 1745236. https://doi.org/10.1155/2020/1745236
Paul, T.; Hossen, M. F. Schiff base metal complexes: Synthesis, characterization, thermal analysis and antibacterial activity. Asian Journal of Research in Chemistry. 2020, 13 (4), 265–274. https://doi.org/10.5958/0974-4150.2020.00052.8
Radhi, E. R.; Ali, F. J.; Ali, K. J. Synthesis and characterization of a new azo quinoline ligand and its metal complexes with spectrophotometric determination and biological efficacy study of its Hg (II) complex. Bulletin of the Chemical Society of Ethiopia. 2023, 37 (6), 1423–1433. ttps://doi.org/10.4314/bcse.v37i6.10
Raj, J.; Jain, A.; Sharma, N.; Kumari, A.; Fahmi, N. Synthesis, spectral characterization, and biological activities of novel palladium (II) and platinum (II) complexes of active Schiff base ligands. Bulletin of the Chemical Society of Ethiopia. 2023, 37 (6), 1383–1396. https://doi.org/10.4314/bcse.v37i6.7
Rana, A. K.; Parekh, N. R.; Dabhi, H. R.; Nadkarni, S. S. Novel Synthesis and Characterization of Thiosemicarbazone Compounds Containing 4‐Acyl‐2‐pyrazolin‐5‐ones. Journal of Chemistry, 2009, 6 (3), 747–752. https://doi.org/10.1155/2009/472530
Soliman, A. I. A.; Sayed, M.; Elshanawany, M. M.; Younis, O.; Ahmed, M.; Kamal El-Dean, A. M.; Abdel-Wahab, A. A.; Wachtveitl, J.; Braun, M.; Fatehi, P.; Tolba, M. S. Base-Free Synthesis and Photophysical Properties of New Schiff Bases Containing Indole Moiety. ACS omega. 2022, 7 (12), 10178–10186. https://doi.org/10.1021/acsomega.1c06636
Srivastava, K.; Singh, A.; Singh, S. K. Green and efficient synthesis, characterization and antibacterial activity of Copper (II) complexes with unsymmetrical bidentate Schiff base ligands. IOSRJ. Appl. Chem. 2014, 7 (4), 16–23. https://doi.org/10.9790/5736-07411623
Sultan, M.; Hassan, S. S.; Omran, K.; Hassan, H. A novel Ni–Schiff base complex for motivating glucose electrooxidation in alkaline solutions. Materials Advances. 2024, 5 (3), 1264–1283. https://doi.org/10.1039/D3MA00730H
Tahmasbi, A.; Jafari, A.; Nikoo, A. Synthesis, characterization, and nonlinear optical properties of copper (II) ligand Schiff base complexes derived from 3-Nitrobenzohydrazide and benzyl. Sci Rep. 2023, 13 (1), 10988. https://doi.org/10.1038/s41598-023-38086-w
Uttu, A. J.; Sallau, M. S.; Iyun, O. R. A.; Ibrahim, H. Isolation, characterization and in silico molecular docking studies of two terpenoids from Strychnos innocua Delile root bark for antibacterial properties. Adv. J. Chem. Sect. A. 2022, 5, 241–252.
Zahradnikova, E.; Pichon, C.; Duhayon, C.; Sutter, J. P.; Halas, P.; Drahos, B. Synthesis, structural and magnetic properties of cobalt(ii) complexes with pyridine-based macrocyclic ligand containing two pyridine pendant arms. RSC Adv. 2024, 14 (38), 28138–28147. https://doi.org/10.1039/d4ra02387k

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