Catalytic Potential of Mononuclear Cr(III)-Imine Complexes for Selective Oxidation of Benzyl Alcohol by Aqueous H₂O₂

Abstract

Chromium(III) complexes were derived, as tri-and tetradentate imine chelates, from 2-hydroxy-1-napthaldehyde or 3ethoxysalicylaldehyde with 2-aminophenol or 1,2-phenylenediamine. The catalytic potentials of Cr(III)-imine chelates were probed and tested in the chemoselective benzyl alcohol oxidation to benzaldehyde (BA) within an eco-friendly terminal oxidant (i.e., H 2 O 2 ). The effect of various applicable parameters in the catalytic systems (e.g., solvents, temperature, and catalyst molar ratios) was studied. From the obtained results, it is found that the most favored and suitable solvent applied is acetonitrile at best reaction conditions; temperature 80 °C after 4 h. The mechanistic aspects of the Cr(III)-catalyzed oxidation were tentatively described and discussed based on electron and oxygen transfer processes.

Synthesis, Characterization, Biological Activity and Solid-State Electrical Conductivity Study of Some Metal Complexes Involving Pyrazine-2-Carbohydrazone of 2-Hydroxyacetophenone

“…For the thermal degradation data of the complexes, various kinetic and thermodynamic parameters such as activation energy (E a ), frequency factor (Z), entropy (S), enthalpy of activation (ΔH), and Gibbs free energy (ΔG) were evaluated by employing the most popular Coats-Redfern relation [41] and values are given in Table 7. The parameters ΔH, ΔS, and ΔG were calculated by using and ΔG = ΔH − T ΔS, where k is Boltzmann's constant and h is plank's constant [42,43,44,45]. The reactions are classified on the basis whether they give off heat as exothermic (ΔH < 0) for absorb heat as endothermic (ΔH > 0).…”

Antioxidant Activity, Molecular Docking and Quantum Studies of New Bis‐Schiff Bases Based on Benzyl Phenyl Ketone Moiety

“…Aromatic or long chain primary amines can react with aldehydes or ketones to form Schiff bases in both basic and acidic media [14,15] . There are a range of synthesized organic compounds (natural or synthesized) that contain imine or azomethine groups [16] . Schiff bases, di‐imines or bis ‐Schiff bases have a broad biological potential and increased their significance during the past few years [17–23] .…”

“…[14,15] There are a range of synthesized organic compounds (natural or synthesized) that contain imine or azomethine groups. [16] Schiff bases, di-imines or bis-Schiff bases have a broad biological potential and increased their significance during the past few years. [17][18][19][20][21][22][23] These compounds are typically synthesized by the condensation of aliphatic or aromatic aldehydes with primary amines (aliphatic or aromatic) using a catalytic amount of acid or base.…”

Schiff bases as analytical tools: synthesis, chemo-sensor, and computational studies of 2-aminophenol Schiff bases

“…[1][2][3] Chemo-sensors are molecules that can detect changes in one or more physicochemical properties. 4,5 The simplicity, low detection limits, high selectivity and sensitivity, cost-effectiveness, real-time monitoring with short response time, and versatility in most chemo-sensor design and applications contribute to the special attention in this area of research. [6][7][8][9] The vital role of metal ions in biological systems comes from the uncontrolled amount of these ions and their recommended amount in food, water, and biological fluids.…”