Chemical Methodologies

Abstract The cyclic voltammetry of different concentrations of mercuric chloride in 0.05 M NaClO₄ as a supporting electrolyte was studied in the absence and presence of diamond fuchsin as magneto dye at K using a glassy carbon electrode as the working electrode. The effects of scan speeds (rate) were also studied, and the evaluated data were discussed. Diamond Fuchsin (rosaniline hydrochloride) magneto dye was used as a complexion material. The different solvation, kinetic, and thermodynamic parameters were evaluated from the cyclic voltammograms and found weak interaction between the magneto dye used and mercuric ions. Mercuric chloride can undergo redox reactions and studying its cyclic voltammetry provide insights into its electrochemical properties and have some potential important uses , like, sensor development and toxic estimation in environmental monitoring and electroplating studies. Safety guidelines should be considered by cyclic voltammatery to follow the toxic mercuric ions.The main target is to estimate the qualitative and quantitative concentration of very toxic mercuric ions as safely and fast.

Abstract A new oxovanadium (V) complex, 2-[(E)-(O-hydroxyplenyl) methylideneamino]-5-guanidinovalerat (quinoline-8-olatoN,O) vanadium oxide (V), [VO(L)(Hq)], (L=(Z)-2-(2-hydroxybenzylideneamino)-5-guanidinopentanoic acid, Hq=quinolin-8-ol), was synthesized from vanadyl acetylacetonate, 2-hydroxybenzaldehyde, L-Arginine, and quinolin-8-ol in methanol, and characterized by ¹H-NMR, ¹³C-NMR, UV-Vis, FT-IR spectroscopy, cyclic voltammetry, and elemental analysis. Analytical data confirmed the coordination of ligand to vanadium in a 1:1 ratio, forming a stable octahedral complex. Antimicrobial activity of [VO(L)(Hq)] was compared to methoxyoxobis (quinoline-8-olato-k²N,O) vanadium(V), [VO(Hq)₂(CH₃O)], which has no Schiff base ligand, by testing against Gram-positive, Gram-negative bacteria, and Candida albicans fungus. The [VO(L)(Hq)] exhibited enhanced antibacterial and antifungal properties attributed to the azomethine group of the Schiff base. The Schiff base ligand coordination provides an effective approach for tuning the biological properties of metal complexes. These results highlight [VO(L)(Hq)] as a potential new antimicrobial therapeutic agent.

Abstract The cyclic voltammetry of different concentrations of lead nitrate was studied in 0.1 M NaCl as aqueous solution in absence and presence of Favipiravir or Fuchsine at 302.15 K using (glassy carbon electrode, GCE) as a working electrode. Favipiravir and Fuchsin were used as complex materials. The effect of different scan speed was studied and the evaluated data were discussed. The different solvation, kinetic and thermodynamic parameters were also evaluated from the cyclic voltammograms to find weak interaction between Favirpiravir with lead ions than that of Fuchsin.

Abstract The study examined the reactions of hexamethyl phosphorous triamide (HMPA) 1, dialkyl acetylenedicarboxylates 2, and benzimidazole 3 (NH-acids) by conducting comprehensive kinetic analyses. Kinetics and mechanistic analysis of the reaction were investigated using theoretical and experimental methods. UV-Vis technique was employed to track experimental data whereas ab initio was employed to investigate theoretical studies revolving around the carbon-carbon double bond (OCH₃-C C-P (NMe₂)₃) in phosphorus ylides 4a-b. Using UV-Vis spectrophotometry, the second-order fits were automatically drawn, and the second-order rate constants (k₂) were computed by the standard equations within the program. Calculations were made for the reaction's activation energy and parameters (E_a, DH^#, DS^# and DG^#). Likewise, the gathered data on how the solvent, reactant structure, and reactant concentration affected reaction rates. The suggested mechanism was verified through experimental data and the steady state approximation, the rate-determining step (RDS) found to be the first and the third steps (k₂ and k₃). Three proposed mechanisms were hypothesized through quantum mechanical calculations. However, the second and the third mechanisms did not match with the experimental data, while the first mechanism showed agreement between theoretical and experimental kinetic data. It was found that the HF/6-31G (d, p) basis set provided more accurate results for compound 4a than the B3LYP/6-31G (d, p) basis set did, whereas the latter performed better for compound 4b.

Abstract In this research study, UV irradiation was employed to decrease the free fatty acids (FFAs) of waste cooking oil (WCO). In the first step, under the UV irradiation, the photocatalytic reaction of Cr-TiO₂ with methanol and free fatty acids in WCO was studied. Optimization was performed with Design Expert Software and using the Box- Behnken method. We investigated the effects of the main parameters, including the molar ratio of methanol to WCO, irradiation time, and type of photocatalyst. By using UV radiation, 0.9661% of the response changes were justified with a Quadratic model. The methanol-to-WCO ratio parameter showed a positive effect with a greater slope. The transesterification reaction of triglycerides with methanol was performed in the second step using the Verma method. Solid catalysts were found to be highly active for the photo-esterification of FFAs with methanol in the UV irradiation. While performing the esterification step in the presence of the UV irradiation in the presence of Cr-TiO₂ photocatalysts, the efficiency was 76.3%-89.5%. The order of photocatalytic esterification reaction by Cr-TiO₂ was approximately equal to one. The kinetics of the transesterification stage was investigated. The first-order kinetic model showed a correlation coefficient of R² = 0.997. The amount of activation energy was 7.103 kJ/mol, indicating the warming nature of the reaction. Concerning the production of H⁺, CH₃O^. and R-COOH on the photocatalyst surface, a possible reaction mechanism for the esterification process is proposed. For the mechanism of the transesterification reaction, ^-OH or ^-OR were considered active species.