Bulletin of the Chemical Society of Ethiopia

Utilisation of charge transfer complexation reactions for the quantification of antifungal drug: Voriconazol in pure and dosage forms

Sabry A. El-Korashy — 2024-11-25

Voriconazole, a pivotal antifungal agent, has been analysed using two uncomplicated, sensitive, rapid, and validated spectrophotometric methods. These procedures rely on the formation of charge transfer complexes in methanol, employing alizarin red S and quinalizarin as chromogenic reagents, each exhibiting absorption maxima at 568 and 513 nm, respectively. The optimisation of reaction conditions was explored, encompassing the choice of solvent, reagent concentration, and reaction duration. Both alizarin red S and quinalizarin demonstrated excellent adherence to Beer's law over concentration ranges of 1.0-18 and 1.0-24 µg mL^-1, respectively, with robust correlation coefficients (r² ≥ 0.9993) and minimal relative standard deviations (RSD% ≤ 1.04). Additionally, calculations were conducted for molar absorptivity (1.1256×104 and 1.7624 ×104 L mol^-1 cm^-1), Sandell sensitivity (31.0 and 19.82 ng cm^-2), detection and quantification limits (0.3 and 1.0 µg mL^-1) for alizarin red S and quinalizarin, respectively. Both methods were effectively applied for the determination of voriconazole in dosage forms, and their validity was confirmed using the standard addition technique. The results obtained from these proposed procedures for pure and dosage forms closely matched those from previously reported methods.

KEY WORDS: Voriconazole, Spectrophotometry, Charge transfer complex, Dosage forms, Method validation.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 189-200.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.1

Incorporation of ginger peel polyphenol into yogurt improves its stability: Physicochemical and microbiological characterizations

Abdulrahman A. Almehizia — 2024-11-25

Microencapsulation is a novel process of plant-extracted polyphenol enrichment into yogurt to extend storage stability with improved quality. This study was intended to develop and characterize functional yogurt that had been microencapsulated with ginger-extracted polyphenol to observe stability at refrigeration temperature (4 ± 1 °C). The phenolic content, microencapsulation efficiency, physiochemical properties, texture, microbiological, and sensory properties were evaluated. The microencapsulation efficiency was found to be 94.40 ± 0.05%. In comparison to the dairy yogurt, the polyphenol-enriched yogurt was darker and had a lower a* (redness to greenness) value and a higher b* (yellowness to blueness) value. Yogurt with added polyphenols decreased the rate at which the pH changed. The phenolic yogurt sample outperformed the control yogurt in terms of water-holding capacity and syneresis. The texture of the treated sample was also superior after three weeks of storage compared to the control. In phenolic yogurt, the rate of Lactobacillus viability decline was reduced. Including ginger extract in yogurt reduced the sensory score in color, flavor, taste, and overall acceptability, but the decreasing rate was reduced. This study demonstrates that the ginger extract polyphenol can be effectively microencapsulated to increase yogurt stability under refrigeration.

KEY WORDS: Ginger, Polyphenols¸ Microencapsulation, Yogurt, Shelf life

Bull. Chem. Soc. Ethiop. 2025, 39(2), 201-213.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.2

Greenness assessment of continuous FIA-spectrophotometric method for quantitation of oxymetazoline in bulk and pharmaceutical forms

Ghadah Fadhil — 2024-11-25

An accurate and cost-effective method utilizing continuous flow injection spectroscopy has been developed for analyzing oxymetazoline hydrochloride in pharmaceutical and bulk powder forms. This new method involves reacting drug in an alkaline solution with diazotized 4-chloroaniline to produce an orange dye with a maximum absorption at λ_max of 483 nm. The flow injection analysis approach was extensively studied in terms of both chemical and physical characteristics to achieve high sensitivity. Within a concentration range of 50-150 μg/mL and a detection limit of 10.4 μg/mL, oxymetazoline hydrochloride follows Beer's law when the experimental variables are optimized. The method's effectiveness was confirmed by achieving high reproducibility of less than 2% (n = 5). A statistical analysis comparing the proposed method to the standard spectrophotometric technique using F and t tests shown no significant differences in accuracy and precision. Additionally, the analytical greenness assessment and the green analytical procedure index were applied to assess the method's greenness and the results demonstrated that the flow injection analysis method satisfies the criteria of green analytical methodologies.

KEY WORDS: Flow injection analysis, Diazotization reaction, 4-Chloroaniline, Oxymetazoline hydrochloride

Bull. Chem. Soc. Ethiop. 2025, 39(2), 215-226.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.3

Evaluation of the greenness profiles of indirect spectrophotometric methods for estimation of gemifloxacin mesylate in pure and dosage forms utilizing N-bromosuccinimide as a green reagent

Samya Sh. Alenezi — 2024-11-25

A validated, sensitive, user-friendly, precise, and dependable spectrophotometric technique has been developed to accurately detect the concentration of gemifloxacin mesylate in pure and dosage forms. The methods utilize N-bromosuccinimide as an eco-friendly oxidizing agent in acidic circumstances. The residual N-bromosuccinimide is measured by subjecting it to a chemical reaction with preset amounts of dyes, amaranth, methylene blue, and indigocarmine and the absorbance is measured at λ_max of 520, 664 and 610 nm, respectively. The analytical technique was implemented and validated by thoroughly examining and optimizing various factors that could potentially disrupt the reaction. Significant linear relationships, characterized by correlation coefficients ranging from 0.9993 to 0.9996, were observed under optimal conditions. These associations remained consistent throughout concentration ranges of 1.0-18, 1.0-14, and 1.0-20 µg/mL. The limits of detection (LOD) of 0.30, 0.29, and 0.30 µg/mL for amaranth, methylene blue, and indigocarmine methods, respectively. The accuracy and precision of the approaches' have been evaluated. No significant interference was observed with the usual pill excipients. In addition, the environmental impact of the suggested processes was assessed using three evaluation tools specifically designed to measure environmental friendliness: the Analytical Greenness Metric, the Green Analytical Procedure Index and Analytical Eco-Scale.

KEY WORDS: Gemifloxacin mesylate, N-bromosuccinimide, Spectrophotometry, Method validation, Dosage forms, Greenness assessment tools.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 227-242.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.4

Levels of selected toxic heavy metals in the root of Rumex abyssinicus, a traditional medicinal plant, collected from two locations in the city of Addis Ababa

Yemariam Mekuanint — 2024-11-25

In this study, the contents of selected heavy metals; Fe, Cu, Zn, Cd, Cr, Pb and Ni in the root of Rumex abyssinicus (RA) were determined by flame atomic absorption spectroscopy (FAAS) after acid digestion. The digestion required 3:1 HNO₃/HCl (v/v) for 3 h, with temperature of 300°C for complete digestion of 0.5 g RA roots using Kjeldahl apparatus. The levels of metals; Fe, Zn, Cu and Ni were 31.9, 7.76 and 4.73 mg kg^-1, respectively, for the samples collected from Addis Ababa University, AAU, Science campus (RA-A samples), and 5.59 Zn, 103 Fe and 3.01 Ni, all in mg kg^-1, were found in RA-W sample from Weregenu/Gerji area in AA. Validity of the optimized procedure was evaluated using spiked sample whose recovery varied from 89.8-95.1%. The findings confirmed that only Fe was higher than the tolerance limits. From the health risk perspective, the hazard quotient (HQ) value of Fe for both RA-A and RA-W samples exceeded 1, indicating potential health risks. The hazard index (HI) value suggested that consumption of the root of RA-A and RA-W samples could pose potential health risks over long-term consumption. This may signify the non-carcinogenic health risk associated with consuming RA plant, though continuous regulatory control may necessitate to ensure safety to the consumers.

KEYWORDS: Medicinal plant, Wet digestion, Rumex abyssinicus, Trace metals, Health risk assessment, Pearson correlation.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 243-256.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.5

Synthesis and spectroscopic characterizations of zinc(II) oxide in nanosized range as a smart materials in treatment and recycling of wastewater

Mohamed Y. El-Sayed — 2024-11-25

The new reaction between zinc(II) chloride and glutaconic acid (C₅H₆O₄) was studied. The results indicate the formation of zinc(II) glutaconate complex with a molar ratio of metal to organic ligand (glutaconic acid) of 2:1 with the general formula [Zn₂(C₅H₄O₄)(Cl)₂(H₂O)₂].4H₂O. The infrared spectrum of the glutaconate suggested that the two carboxylate groups are bidentate chelating. The current study uses a thermal breakdown approach to synthesize zinc oxide (ZnO) nanoparticles (NPs). The synthesized ZnO NPs were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and Fourier transform infrared spectroscope (FTIR). The crystallite size was calculated using Scherer's formula, which was 54 nm. The degradation of hydrogen peroxide, or H₂O₂, solution was used to test the produced ZnO NPs' catalytic activity performance. The results showed that ZnO NPs could efficiently break down H₂O₂. The ZnO NPs' photocatalytic capabilities have been assessed using methylene blue (MB) and UV light in an aqueous solution, according to the data, 77% of photocatalytic degradation towards MB in 240 min occurs.

KEY WORDS: ZnO NPs, Methylene blue dye, Photocatalytic, Metal-glutaconate complexation.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 257-270.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.6

Green synthesis, characterization, antimicrobial and anti-cancer activity of silver nanoparticles using Aristolochia bracteolate plant leaf extract: experimental and theoretical calculations

P. Durairaju — 2024-11-25

Silver nanoparticles were synthesized using Aristolochia bracteolate plant extracts. The nanoparticles were subsequently studied using various techniques such as UV-Vis, FTIR, EDS, XRD, SEM, and HR-TEM analysis. MTT assays have been utilized to determine the cytotoxicity of green synthesized silver nanoparticles at concentrations ranging from 2.5 to 15 μg. The Ab-AgNPs exhibited effective cytotoxic activity against MCF-7. Anticancer activity studies revealed that Ab-AgNps produced comparable good results for standard cancer drugs. Ab-AgNPs are used for evaluating their antibacterial effectiveness against pathogenic gram-positive and gram-negative bacteria. Aristolochic acid (AA1) and Aristolochic acid (AA2) are the major phytoconstituents in the Aristolochia bracteolate. The current study reports theoretical investigations of aristolochic acids (AA1 and AA2) as well as silver nanocages aristolochic acids using density functional theory. Furthermore, the silver-doped with Aristolochic acids (AA1 and AA2) was subjected and examined their of breast cancer activity using molecular docking analysis.

KEY WORDS: Aristolochia bracteolate, Silver nanoparticles, Transmission electron microscopy, Docking, Anti cancer active

Bull. Chem. Soc. Ethiop. 2025, 39(2), 271-286.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.7

Synthesis, characterization, antioxidant activity, docking and simulation of potential anticancer agents of azo dye for pyridyl and its palladium(II) complex

Hasan Mohammed — 2024-11-25

Herein, we describe the preparation and characterization of a novel azo dye of pyridyl, namely, (E)-N-(4-hydroxy-3-(pyridin-3-yldiazenyl)phenyl)acetamide (EHPYPA) and its palladium(II) complex. The palladium(II) complex bears the formulation [Pd(EHPYPA)Cl], which is reported by electrospray ionization mass spectrometry, CHN analysis, FT-IR, UV–Vis, ¹HNMR spectroscopies, molecular docking and simulation. The synthesis and structural properties of the azo dye and its palladium(II) complex are reported. The EHPYPA ligand showed important changes in the colours and spectra at different values of acidity, which permit to use of it as an indicator in analytical chemistry. The EHPYPA ligand behaves as N,O-bidentate donor ligand forming chelates. The ligand and palladium complex have been screened against the SKOV-3 cell line using the MTT method. Furthermore, the docking results indicate favourable docking with scores were -7.3 kcal/mol, -7.8 kcal/mol, and -11.2 kcal/mol for the ligand, palladium complex and Co-crystal. RMSD values for the prepared compounds indicate stability while PSA, MolSA and SASA values indicate favorable drug-like potentials for the ligands. The palladium complex has been investigated as an anticancer agent where the activity data had shown that the palladium metal complex has to be a more potent anticancer than the parent azo ligand, suggesting that metalation increases the anticancer activity of the azo ligand of pyridyl.

KEY WORDS: Cell line, Palladium, Azo, Complex, Indicator, Molecular docking

Bull. Chem. Soc. Ethiop. 2025, 39(2), 287-300.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.8

Synthesis of some novel dipeptides and their copper(II) complexes of (dibenzo [b, d] furan-2-ylsulfonyl) phenylalanine

Gaber O. Moustafa — 2024-11-25

A new series of dipeptide candidates (6-11) and corresponding octahedral copper complexes (12-15) were prepared by the synthesis of dibenzofuran-2-sulfonyl chloride (3). Then, the acid chloride (3) was coupled, at low temperature, with DL-phenylalanine using triethylamine and gave the corresponding acid (4) as starting material, which was converted to dibenzofuran-2-sulphonyl-DL-phenylalanyl chloride (5) using thionyl chloride. The latter acid chloride (5) was coupled with some aliphatic amino acids and gave the corresponding dibenzofuran-2-sulphonyldipeptide candidates (6, 7). Moreover, dibenzofuran-2-sulphonyldipeptide methyl ester derivatives (8, 9) were prepared via the esterification of the corresponding candidates (6, 7) and hydrazinolysis with hydrazine hydrate 99% of methyl esters (8, 9) to give the corresponding peptide hydrazides (10, 11). Then, all the newly prepared peptide derivatives (6-11) were reacted with copper acetate to afford the corresponding copper complexes (12-15). The newly synthesized compounds (6-15) were characterized.

KEY WORDS: Dibenzofuran-2-sulfonyl-DL-phenylalanyl chloride, Amino acids, Linear dipeptides, Copper complexes.

Bull. Chem. Soc. Ethiop. 2025, 39(2), 301-311.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.9

Synthesis, characterization, and biological evaluation of zinc(II) complexes with benzohydrazide derivative and phosphine ligands

Nazk M. Aziz — 2024-11-25

New zinc(II) complexes of the mixed ligands were synthesized using a benzohydrazide derivative (L), yielded from reaction of benzohydrazide and isatin, in combination with (Phen) and various phosphine co-ligands, including 1,10-phenanthroline (Phen), 1,2-bis(diphenylphosphino)ethane(dppe), 1,2-bis(diphenylphosphino) propane (dppp), and triphenylphosphine (PPh₃). Characterization methods included molar conductivity, atomic absorption, FTIR, and ¹H, ¹³C{¹H},³¹P{¹H}-NMR spectroscopy, confirming tetrahedral geometry around zinc(II) with the ligand N'-(2-oxoindolin-3-ylidene) benzohydrazide (L) acting as a bidentate chelating ligand. The thermogravimetric (TG) analysis of the papered complexes [Zn(L)(Phen)]Cl₂, [Zn(L)(PPh₃)]Cl₂, and [Zn(L)(dppp)]Cl₂ showed that each of them has been decomposed in three stages. The in vitro biological activities were evaluated against four types of bacteria, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, and Escherichia coli, along with cancer human liver (Hep-G2) cell lines, revealing that the complexes exhibited significant cytotoxicity. Notably, the [Zn(L)(Phen)]Cl₂ complex showed the strongest inhibitory effect on human liver (Hep-G2) cells, with an IC₅₀ of 31.12 ± 1.57 μM. Antibacterial tests indicated that [Zn(L)(Phen)]Cl₂ and [Zn(L)(dppp)]Cl₂ complexes effectively inhibited Streptococcus faecalis, and [Zn(L)(Phen)]Cl₂ also had limited efficacy against Gram-negative bacteria. Structure-activity relationship studies highlighted that the choice of phosphine ligand significantly influences the biological properties of these zinc(II) complexes.

KEY WORDS: Antibacterial, Anticancer, Benzohydrazide derivative, Mixed ligands complexes, Phosphines, Spectroscopy

Bull. Chem. Soc. Ethiop. 2025, 39(2), 313-326.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.10

Complexes of the antibiotic drug succinylsulfathiazole with the La(III), Sm(III), and Tb(III) ions: Spectral characterizations, microscopic pictures, and thermal properties

Abdulrahman A. Almehizia — 2024-11-25

Reacting the antibiotic drug succinylsulfathiazole (abbreviated as SST) with the lanthanide metal ions La(III), Sm(III), and Tb(III) generated thermal stable metal-based complexes. The temperature of the reaction was 70 ^oC, at a pH of ~ 8.5, using stoichiometry of 2:1 (SST ligand to metal ion). Spectral and analytical characterizations of the SST metal-based complexes were obtained using ultraviolet/visible (UV-visible), Fourier-transform infrared (FT-IR) spectroscopies, X-ray diffractometry (XRD), and CHN elemental analysis. The microscopic pictures of the SST complexes were captured by a high-resolution scanning electron microscope with environmental mode (ESEM). Experimental data suggested that the general composition of La(III) complex is [La(SST)₂(H₂O)Cl].6H₂O with a gross formula of C₂₆H₃₈N₆O₁₇S₄ClLa, the general composition of Sm(III) complex is [Sm(SST)₂(H₂O)(NO₃)].5H₂O with a gross formula of C₂₆H₃₆N₇O19S₄Sm, whereas the general composition of Tb(III) complex is [Tb(SST)₂(H₂O)(NO₃)].4H₂O with a gross formula of C₂₆H₃₄N₇O₁₈S₄Tb. In the manufactured complexes, two deprotonated SST molecules were captured the La(III), Sm(III), and Tb(III) ions by their bidentate carboxylate groups (COO^-). The microscopic pictures clearly revealed different surface topography between SST metal-based complexes.

KEY WORDS: Succinylsulfathiazole, Lanthanides, SEM, Surface morphology, EDS profile

Bull. Chem. Soc. Ethiop. 2025, 39(2), 327-339.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.11

Exploring the half-metallic behavior and spintronic potential of Cr-doped CaTe

M. Drissi El Bouzaidi — 2024-11-25

The pursuit of miniaturized, high-performance electronic devices has intensified research into novel materials with extraordinary properties. While semiconductors lead the way in optoelectronics and energy harvesting, the burgeoning field of spintronics utilizing electron charge and spin promises revolutionary advances in information processing and storage. A critical component of spintronics is identifying materials with half-metallic behavior, characterized by complete spin polarization at the Fermi level. This study explores chromium (Cr)-doped CaTe as a candidate for half-metallic behavior. Using advanced computational techniques, we investigate the impact of Cr doping on the electronic and magnetic properties of CaTe. Our findings reveal that Cr-doped CaTe exhibits significant crystal field splitting and exchange splitting energies, leading to robust magnetic properties and half-metallic behavior across varying doping concentrations. Notably, the Curie temperature of Cr-doped CaTe exceeds room temperature starting from a 14% Cr concentration, highlighting its practical viability for spintronic applications. The results underscore the potential of Cr-doped CaTe for integration into spintronic devices, offering insights into the electronic structure and magnetic interactions essential for developing next-generation spintronic technologies.

KEY WORDS: Half-metallic behavior, Spintronics, Chromium doping, Curie temperature, Magnetic properties, CaTe (Calcium telluride).

Bull. Chem. Soc. Ethiop. 2025, 39(2), 341-350.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.12

GC-MS profiling and in silico pharmacokinetic properties of essential oils hydrodistilled from leaves of Capparis tomentosa and Cadaba rotundifolia

Teshome Degfie — 2024-11-25

In Ethiopian traditional medicine Capparis tomentosa treats tuberculosis, diarrhea, epilepsy, and malaria, while Cadaba rotundifolia for arthritis, tonsillitis and snake bites. Essential oils from the plant leaves were hydro-distilled using Clevenger apparatus and analyzed by GC-MS. SwissADME and ProTox-II assessed drug-likeness and ADMET of major compounds. Leaf extracts were tested against three bacterial strains using agar disc-diffusion method. GC-MS identified 25 compounds (89.7%) in C. tomentosa and 23 (95.47%) in C. rotundifolia. Major compounds (1-15) followed Lipinski's and Veber's rules, with compounds 2, 7, 9, and 12 in the Boiled-Egg's yellow region. Compounds 3, 4, 7, 11, and 12 had LD50 >5000 mg/kg, indicating lower toxicity than chloramphenicol (LD₅₀ = 1500 mg/kg). At 5 μg/mL, C. tomentosa oil showed stronger inhibition against E. coli (10±0.0 mm) and P. aeruginosa (9.0±0.25 mm), its methanol and n-hexane extracts against E. coli (9.85±0.14 mm) and P. aeruginosa (8.1±0.19 mm), respectively. C. rotundifolia oil was more effective against P. aeruginosa (8±0.5 mm) than chloramphenicol (6.9±0.51 mm), while its n-hexane and methanol extracts inhibited P. aeruginosa (8.1±0.17 mm) and E. coli (8.0±0.31 mm), respectively. These findings support traditional medicinal use of the studied plants, and highlight their potential as sources of bioactive compounds.

KEY WORDS: Capparis tomentosa, Cadaba rotundifolia, Essential oils, GC-MS, In silico pharmacokinetic

Bull. Chem. Soc. Ethiop. 2025, 39(2), 351-366.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.13

Facile synthesis of thiophene-embedded Baicalein via oxidative cyclization and anticancer activity against ovarian cancer cells via inhibiting PI3K/MTOR signaling pathway: in-vitro and in-silico study

Zheqi Liu — 2024-11-25

This study illustrated the synthesis of a thiophene-embedded Baicalein (BAC) conjugate through the formation of a chalcone backbone, accomplished by refluxing hydroxyl-acetophenone with 5-nitrothiophene-2-carbaldehyde in the presence of piperidine. The BAC conjugate (5,6,7-trihydroxy-2-(5-nitrothiophen-2-yl)-4H-chromen-4-one) was obtained through the oxidative cyclization of the previously synthesized chalcone using DMSO/I2. The structure of BAC was determined by FTIR, 1H-NMR, 13C-NMR, mass spectrometry, and elemental analysis. The impact of BAC on SKOV-3 ovarian cancer cells was assessed via several pharmacological assays, including viability, apoptosis, migration, invasion, and cell cycle analysis. RT-qPCR analysis was performed to assess the impact of BAC on the mRNA levels of Bcl2, Bax, PI3K, Akt, and mTOR. BAC underwent docking analysis utilizing the 3D crystal structure of PI3K. The results indicate that BAC decreases cell viability, migration, invasion, and induces cell cycle arrest at the G2/M phase in SKOV-3 cells in a concentration-dependent manner. The Annexin FITC assay demonstrated the activation of apoptosis by increasing Bax expression and decreasing Bcl2 expression. The mRNA expression of PI3K, Akt, and mTOR was considerably suppressed relative to the untreated control, potentially through interactions with Trp201, Gln291, Leu657, Arg690, Phe694, and Arg849 of PI3K.

Keyword: Cell-viability, Apoptosis, Migration, Cell-cycle, RT-qPCR, Docking

Bull. Chem. Soc. Ethiop. 2025, 39(2), 367-379.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.14

Uncovering benzoquinone derivatives for redox flow batteries: DFT insights on reduction potentials and solvent effects

Getachew Abera Negesse — 2024-11-25

Quinones possess high redox potential, making them suitable for organic redox-flow batteries. Their oxidation and discharge during charging involve two reversible electron transfer reactions. This study utilized density functional theory (DFT) with the B3LYP functional and 6-31G(d) basis set to calculate the first and second reduction potentials of benzoquinones (BQ). Various BQ derivatives were created by adding electron-donating substituents (-NHCH₃, -NH₂, -OCH₃, -NHCOCH₃, -OCOCH₃). The universal solvation model (SMD) assessed solvent effects, while lithium salts, solvation-free energy, and HOMO-LUMO energies influenced reduction potentials. The -OCOCH₃-substituted BQ showed the highest first and second redox potentials at 2.81 V and 2.27 V, respectively. Adding boron trifluoride (BF₃) salt increased these potentials to 3.99 V and 3.84 V. The electrochemical behavior of BQ and its derivatives was examined in three solvents: carbon tetrachloride (CCl₄), acetonitrile (ACN), and water (H₂O). The average reduction potentials in these solvents followed the trend CCl₄ < ACN < H₂O, with water being the most effective due to its hydrogen bonding and polarity. These findings highlight the significant impact of solvent characteristics on electrochemical processes.

KEYWORDs: Benzoquinone derivatives, DFT, Electron affinity, Reduction potential, Redox flow battery, Solvation-free energy, SMD solvation model

Bull. Chem. Soc. Ethiop. 2025, 39(2), 381-396.

DOI: https://dx.doi.org/10.4314/bcse.v39i2.15