CHEMICAL PROBLEMS

Abstract: A rapid, sensitive, and indirect spectrophotometric method was developed for the determination of amoxicillin in pure form and in pharmaceutical preparations. The method is based on the oxidation of the pharmaceutical compound amoxicillin in an acidic medium (hydrochloric acid) with a known excess of the oxidizing agent N-bromosuccinimide (NBS); then the unreacted excess of […]

Abstract: The study focused on the synthesis and characterization of mixed-ligand transition metal complexes containing the oxime-based ligand 4-(4-bromophenylaminoisonitrosoacetyl)biphenyl (HL) and the amino acid L-phenylalanine (Phe). Complexes of Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺ were prepared, and their physicochemical properties were systematically investigated. Elemental analysis, molar conductivity measurements, infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) […]

Abstract: The thermoelectric phenomenon in the reference (pristine) and BN-added EuBa2Cu3Oy high- temperature superconductors have been studied. A series of 4 compounds was prepared by the solid-phase synthesis method. The phase evolution of the prepared materials was analyzed by XRD, and the SEM/EDX technique was employed to investigate the microstructure and elemental composition of the […]

Abstract: Heterogeneous composite catalytic systems of the type Me(Zn,W)/KH-4/Al2O3 were investigated in the conversion of the butane–butylene fraction obtained from the catalytic cracking unit of the Heydar Aliyev Refinery Plant. The initial carrier was an industrial catalytic cracking catalyst KH-4, modified with Zn and W salts. The catalysts were tested on a laboratory setup at […]

Abstract: The thermal reduction of ferrocene in a hydrogen atmosphere was investigated over the temperature range of 573–1173 K, focusing on both the gaseous and solid products formed during the process. The gas-phase products (hydrocarbons) and solid products (nanosized iron particles) formed during the reaction were identified. It was shown that, in contrast to the […]

Abstract: This paper investigates alternative conditions for synthesizing salts and toluidides of toluidine isomers with oxalic acid, malonic, and succinic acids. In these syntheses, the salt formation reactions of toluidines with oxalic acid in a 2:1 molar ratio and with malonic and succinic acids in a 1:1 molar ratio at room temperature in ethanol for […]

Abstract: This study is aimed at improving the quality of motor fuels, in particular, reducing the total sulfur content by developing alternative methods – the process of oxidative desulfurization with hydrogen peroxide without the use of hydrogenation processes. The process of oxidative desulfurization with hydrogen peroxide of wide and narrow fractions of GCC and GC: […]

In this study the corrosion behaviors of carbon steel (CS) in simulated concrete solution (KOH, NaOH, Ca(OH)2) was investigated. Current density of corrosion (icorr), potential of corrosion (Ea), anodic and cathodic Tafel slopes (βa, βc) were used to determine the resistance of polarization (Rp). The result indicated that the temperature increasing of the concrete electrolyte […]

Abstract: A synthesis of a new compound (II) with three groups of 1,2-thiazine 1,1-dioxide, called (2-(3,5-bis(3,5,5,6-tetramethyl-1,1-dioxido-5,6-dihydro-2H-1,2-thiazin-2-yl)phenyl)-3,5,5,6-tetramethyl-5,6-dihydro-2H-1,2-thiazine 1,1-dioxide ), was synthesized by reacting moles (1:3) of each of benzene-1,3,5-triamine with 3,4,4,6-tetramethyl-3,4-dihydro-1,2-oxathiine 2,2-dioxide (I), respectively. The last compound (I) was prepared by equal moles of each of (4-methylpent-3-en-2-one) with (sulfonylethane). The structural formula of the resulting compounds […]