Enhancement of Activity of Transition Metals Complex's as a Catalyst in Environmentally Friendly Phenol Oxidation

This study highlights the synthesis, characterization, and catalytic application of a novel copper(II) complex, Cu(II)(FTL), where FTL represents the 2-amino-4-(4-fluorophenyl) pyrazole ligand. Spectroscopic analyses confirmed the successful coordination of the copper(II) ion through the nitrogen atoms of the pyrazole's amino and ring nitrogen groups. The catalytic potential of Cu(II)(FTL) was evaluated for the green oxidation of phenol using hydrogen peroxide (H₂O₂) as the oxidant. Kinetic studies revealed a Michaelis constant (K_m) of 44.7 mM and a turnover number (k_cat) of 2.7 × 10⁻⁷ s⁻¹ for the catalyzed reaction, compared to K_m = 37.6 mM and k_cat = 3.5 × 10⁻⁷ s⁻¹ for the unanalyzed reaction. The higher K_m value in the presence of the catalyst suggests a lower binding affinity for phenol, consistent with a mechanism where H₂O₂ is the primary substrate activated by the copper center. The relatively low k_cat indicates a slow turnover rate, potentially due to stable intermediate formation or slow product release. Despite these limitations, the study demonstrates the potential of Cu(II)(FTL) as a catalyst for environmentally friendly phenol oxidation, paving the way for further optimization and mechanistic exploration.