Macedonian Journal of Chemistry and Chemical Engineering

Ab initio exploration of modified carbon nanotubes as potential corrosion inhibitors

2023-12-27T22:22:58-08:00

In order to develop novel unexplored potential corrosion inhibitors, covalently modified single-walled carbon nanotubes (SWCNT) via benzoic (–PhCOOH) and aniline (–PhNH₂) groups are being investigated as corrosion inhibitors for the first time. Utilizing a comprehensive approach, this study employed density functional theory (DFT), Monte Carlo (MC), and molecular dynamics simulations (MD) to assess the adsorption behavior of modified nanotubes as corrosion inhibitors on the Cu(111) surface within a simulated aqueous HCl corrosion medium. The results provided molecular information on the adsorption capability, geometry adsorption centers, and adsorption energies (E_ads) of carbon nanotubes on the surface of Cu(111). The adsorption energy values unveiled robust interactions between SWCNT–PhCOOH and SWCNT–PhNH₂inhibitors and the Cu(111) surface, suggesting a highly effective corrosion protection mechanism. The calculated E_ads values exhibited notable ranges, spanning from –260.82 to –308.18 kcal/mol for SWCNT–PhCOOH and –220.92 to –261.01 kcal/mol for SWCNT–PhNH₂ with the maximum probability values, representing the most favorable adsorption scenarios, determined to be –292.96 and –229.39 kcal/mol, respectively. A key insight from Monte Carlo simulations underscored the inherent spontaneity of the adsorption process, corroborated by the consistently negative E_ads values. These findings collectively underscore the substantial affinity of the inhibitors to the copper surface, contributing to a deeper comprehension of their corrosion inhibition capabilities.

Experimental biological studies of novel tetradentate hydrazone Cu(II) complexes for potential applications in medicinal chemistry

2024-02-26T23:45:57-08:00

A series of mononuclear Cu(II) complexes were synthesized using a potential tetradentate hydrazone ligand obtained from the reaction between phenylhydrazine groups and 2,5-thiophenedicarboxaldehyde. The structures of ligands and complexes were elucidated through various spectroscopic techniques, confirming their composition. All complexes were found to adopt four-coordinated geometries, indicating the formation of stable structures. Spectroscopic analysis revealed that the hydrazone ligand coordinated with the Cu(II) metal ions as a dibasic tetradentate ligand by utilizing the phenolic oxygen and azomethine nitrogen atoms. The binding affinity of the complexes with calf thymus DNA (CT-DNA) was investigated using absorption and viscosity measurements, demonstrating their interaction through the intercalation mode. The binding studies showed that the Cu(II) complexes exhibited varying degrees of binding affinity, with Cu(L⁴) demonstrating the highest affinity, followed by Cu(L¹), Cu(L²), and Cu(L³). Moreover, the DNA fragmentation properties of the Cu(II) complexes were evaluated, suggesting their potential utilization in pharmaceutical applications. The obtained results highlight the significance of these novel complexes in the field of medicinal chemistry.

A Comment of the comments

2024-01-25T12:30:53-08:00

Commenting on the work of other authors is justified when there are serious concerns related the scientific content, and the authors do not respond with valid arguments so that such concerns cannot be addressed. It should not be used to advertise one’s own work.

Comparative physicochemical investigation of the inclusion compounds of cyclodextrins with arginine and histidine stereoisomers

2023-12-27T04:09:41-08:00

The inclusion complexes of α-, β-cyclodextrin and 2-hydroxypropyl-α-cyclodextrin with two amino acid stereoisomers (L-, D-arginine and L-, D-histidine) were studied by using differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy methods. The solid inclusion compounds were prepared in a 1:1 molar ratio of the host and guest using the co-precipitation method. The pH measurements and structural visualization of complexes were carried out. The obtained results proved the formation of the complexes and revealed that the size and the symmetry of the cyclodextrin (CD) and also the structure and flexibility of the amino acid molecule had a significant influence on the complexation interaction. The correlation of the experimental data shows that βCD has a preference to form more stable complexes with levogir isomers of amino acid than αCD and 2-hydroxypropyl-α-cyclodextrin. The complexation of the amino acids isomers was accomplished by partial inclusion of the guest molecule in the CD cavity, and it was observed that CDs could better discriminate between histidine isomers than between arginine isomers.

Visionary figures in the field of electrochemistry who revolutionized voltammetry

2024-02-28T22:31:06-08:00

Understanding energetics and electron behavior has been pivotal in elucidating numerous fundamental phenomena, including electricity, corrosion, respiration, energy generation in biological systems, intermolecular interactions within living organisms, organic synthesis, drug development, enzyme functions, and the design of biosensors, among others. As 2024 records the centennial anniversary of the completion of the first polarograph by Nobel laureate Jaroslav Heyrovský (awarded the Nobel Prize in Chemistry in 1959), it presents an opportune moment to pay tribute to several eminent electrochemists who have made significant contributions to the field of voltammetric techniques. Following our recent acknowledgment of the outstanding women who have made substantial contributions to voltammetry in a prior publication, this article aims to briefly highlight the major achievements of several distinguished male figures in the field (Jaroslav Heyrovský, Allen J. Bard, Christian Amatore, Richard Compton, Jean-Michel Savéant, Fraser Armstrong, Fritz Scholz, Joseph Wang, Milivoj Lovrić, Valentin Mirčeski, Alan M. Bond). Given that many of these remarkable personalities have contributed both as authors and referees for the Macedonian Journal of Chemistry and Chemical Engineering, this tribute serves as a fitting acknowledgment of their remarkable accomplishments on the occasion of the journal's 50th anniversary.