METHODS OF ANALYSIS OF SUBSTANCES SYNTHESIZED VIA ETHYLENE TELOMERIZATION REACTION

Аннотация

This scientific work explores the synthesis of isopropyl and isoamyl alcohols via telomerization of ethylene with methanol under high-pressure hermetic reactor conditions. Various analytical methods including IR spectroscopy, chromatographic-mass spectrometry, Raman spectroscopy, physicochemical, quantum chemical, and mathematical modeling were used to study and identify the structure and properties of the synthesized compounds. The analysis included the determination of boiling point, density, refractive index, and molecular refraction. IR spectra were obtained using the “INVENIO-S FTIR” spectrometer, and Raman spectra were recorded with the “InVia Raman BRAVO” device. Chromato-mass analysis was conducted using the Agilent MSD 5975C-GC7890A spectrometer. Quantum chemical calculations were performed via HyperChem Professional software, while mathematical modeling and experimental data processing were conducted using Maple 2018, applying the method of least squares. Density was determined using pycnometers, and refractive indices were measured by an Abbe refractometer. Keywords Ethylene telomerization, isopropyl alcohol, isoamyl alcohol, IR spectroscopy, Raman spectroscopy, chromatographic-mass spectrometry, quantum chemical modeling, mathematical modeling, refractive index, molecular refraction, physical properties. In the scientific research, IR spectroscopy, chromatographic-mass spectrometry, Raman spectroscopy, physicochemical, quantum chemical, and mathematical modeling methods were used. The structure and composition of the products obtained through chemical synthesis processes were studied and analyzed. Chromatographic-mass spectra were obtained in the liquid phase using a standard HP-5MS column on an “Agilent MSD 5975C-GC7890A” chromatograph-mass spectrometer, operating in the temperature range from 0 °C to 320 °C, with initial heating from 50 °C to 120 °C. In the chromatographic- mass spectrum of the synthesized isopropanol, ions corresponding to the 82 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference molecular mass of the compound and fragment ions resulting from decomposition were identified. The IR spectra of the synthesized compounds were obtained using the “INVENIO-S FTIR” spectrometer, manufactured by Bruker in 2021, which has an optical spectral resolution of less than 0.25 cm⁻¹ and operates within the IR spectral range of 4000–400 cm⁻¹. The Raman spectra of the compounds were recorded using the “InVia Raman spectrometer BRAVO.” This spectrometer is particularly suitable for identifying specific features of compounds, such as molecular “fingerprints,” and for observing the state, tension, and deformation changes in molecular bonds. During analysis, the laser beam was focused on sample areas with a diameter of 10 µm to determine volume. Quantum chemical calculations are among the physicochemical research methods used to evaluate the geometry of molecules, calculate the stability of intermediates and transition states, and determine the properties of complex organic compounds. The chemical properties and reactivity of molecules depend on their electronic structure and energetic characteristics. Within the scope of the dissertation, quantum chemical calculations were conducted using the “HyperChem Professional” software to study the formation energy, total energy, heat of formation, electronic energy, electron density distribution, nuclear energy, dipole moment, and possible reaction pathways of both the initial and synthesized substances. Mathematical modeling of the process and processing of experimental data – Mathematical modeling and data processing methods make it possible to identify chemical reaction processes in a short time and optimize them, enabling modern design with minimal cost and time. The synthesis processes of isopropyl and isoamyl alcohols were mathematically modeled and their experimental data processed using the least squares method in the Maple 2018 software. Determination of density. In chemical industry laboratories and pharmaceutical plants, pycnometers are typically used along with hydrometers for technical analyses. Density is one of the indicators used in various industrial facilities to determine the quality of liquid substances. It helps verify whether the properties of raw materials and finished products comply with established standards. Before starting the analysis with the pycnometer, it was thoroughly rinsed with a chromic acid mixture, followed by distilled water. First, the clean and dry pycnometer was weighed on an analytical balance. Then, both the glass vessel 83 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference and distilled water were heated to the same temperature at which the density of the studied liquid was to be measured. The distilled water was poured into the empty pycnometer up to the calibration mark on its neck. After that, the mass of the pycnometer with water was measured. Then, the