Nickel and oxovanadium complexes as biomimetic catalysts in bromination reaction: A new approach for hydrogen peroxide detection in water
Journal of the Indian Chemical Society, cilt.103, sa.10, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 103 Sayı: 10
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.jics.2026.102918
- Dergi Adı: Journal of the Indian Chemical Society
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, EMBASE
- Anahtar Kelimeler: Schiff base complexes, Redox behavior, Catalytic bromination, Vanadium-dependent haloperoxidase model, Hydrogen peroxide sensing
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
In this study, nickel and oxovanadium complexes with the general formula ML2 (M = Ni or VO) were synthesized using a bidentate NO Schiff base ligand (HL) derived from 2-aminophenol and 5-bromosalicylaldehyde in a 1:2 metal-to-ligand molar ratio. The synthesized complexes were characterized by elemental analysis and spectroscopic techniques, including FT-IR, UV–Vis, 1H NMR and mass spectrometry. Molar conductivity measurements indicated the non-electrolytic nature of the complexes, while thermogravimetric analysis (TGA) revealed the presence of water molecules in the coordination sphere and confirmed thermal decomposition to the corresponding metal oxides. Electronic and vibrational spectroscopic analyses indicated that the NiII complex adopts a square-planar geometry, while a distorted square-pyramidal coordination environment was proposed for the VOIV complex. The electrochemical behavior, investigated by cyclic voltammetry, showed quasi-reversible one-electron redox processes, with characteristic redox couples observed at +265 mV and −1440 mV versus SCE, corresponding to the VOV/VOIV and NiII/NiI systems, respectively. The catalytic activity of the complexes was evaluated through the bromination of phenol red to bromophenol blue in the presence of hydrogen peroxide, bromide ions and phosphate buffer. Both nickel and oxovanadium complexes exhibited good catalytic performance, with differences in activity attributed to their distinct structural and electronic features. These findings highlight the potential of the synthesized complexes as functional models for vanadium-dependent haloperoxidases (VHPOs) and demonstrate the applicability of this catalytic system for hydrogen peroxide detection.