Study of the Electrochemical Behavior of N-Substituted-4-Piperidones Curcumin Analogs: A Combined Experimental and Theoretical Approach

Abstract

The electrochemical behavior of N-methyl- and N-benzyl-4-piperidone curcumin analogs were studied experimentally and theoretically. The studied compounds present different substituents at the para position in the phenyl rings (-H, -Br, -Cl, -CF3, and -OCH3). We assessed their electrochemical behavior by differential pulse and cyclic voltammetry, while we employed density functional theory (DFT) M06 and M06-2x functionals along with 6-311+G(d,p) basis set calculations to study them theoretically. The results showed that compounds suffer a two-electron irreversible oxidation in the range of 0.72 to 0.86 V, with surface concentrations ranging from 1.72 × 10−7 to 5.01 × 10−7 mol/cm2. The results also suggested that the process is diffusion-controlled for all compounds. M06 DFT calculations showed a better performance than M06-2x to obtain oxidation potentials. We found a good correlation between the experimental and theoretical oxidation potential for N-benzyl-4-piperidones (R2 = 0.9846), while the correlation was poor for N-methyl-4-piperidones (R2 = 0.3786), suggesting that the latter suffer a more complex oxidation process. Calculations of the BDEs for labile C-H bonds in the compounds suggested that neither of the two series of compounds has a different tendency for a proton-coupled electron transfer (PCET) oxidation process. It is proposed that irreversible behavior is due to possible dimerization of the compounds by Shono-type oxidation.

Electrochemical Sensing of Curcumin: A Review

“…The electrochemical behavior of N-methyland N-benzyl-4-piperidone curcumin analogs, with different substituents at the para position in the phenyl rings (-H, -Br, -Cl, -CF 3 , and -OCH 3 ), were also studied via DPV and CV. The results showed that these types of compounds also suffer a diffusion-controlled, irreversible, two-electron irreversible oxidation in the potential range from +0.72 to +0.86 V [37].…”

Synthesis, Spectroscopic and Antibacterial Studies of Some N-Phenylpyridinium Chloride Derivatives

“… N-Phenylpyridinium Chloride Derivatives as Potential Anticancer Agents: This research explores the potential of N-phenylpyridinium chloride derivatives as anticancer agents, focusing on their cytotoxic effects on cancer cells and their mechanism of action [27].  Electrochemical Behavior of N-Phenylpyridinium Chloride Derivatives: This work investigates the electrochemical behavior of N-phenylpyridinium chloride derivatives, studying their redox properties and potential applications in electrochemistry [28].  Crystal Structures of N-Phenylpyridinium Chloride Derivatives: This study presents the crystal structures of N-phenylpyridinium chloride derivatives, providing insights into their molecular packing and intermolecular interactions [29].…”

“…Using Fourier transform infrared (FTIR) spectroscopy, the resulting samples were analyzed at frequencies ranging from 4000-500 nm [28].…”