SYNTHESIS, STRUCTURE, AND INVESTIGATION OF A COMPLEX COMPOUND BASED ON THE BENZIMIDAZOLE DERIVATIVE OF Co (II)

383 Volume 5, Issue 10: Special Issue (EJAR) ISSN: 2181-2020 MPHAPP THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “MODERN PHARMACEUTICS: ACTUAL PROBLEMS AND PROSPECTS” TASHKENT, OCTOBER 17, 2025 in-academy.uz SYNTHESIS, STRUCTURE, AND INVESTIGATION OF A COMPLEX COMPOUND BASED ON THE BENZIMIDAZOLE DERIVATIVE OF Co (II) Khujaeva F.A.1,2 Allamurodova SH.G.2 Daminova SH.SH.2 1Tashkent Pharmaceutical Institute, Tashkent, Republic of Uzbekistan 2National University of Uzbekistan, Tashkent, Republic of Uzbekistan [email protected]. tel:(90) 939-63-16 https://doi.org/10.5281/zenodo.17339240 Relevance: Currently, benzimidazole and its derivatives are the main raw materials for the development of important therapeutic agents in medicine and pharmaceuticals. For example, benzimidazole and its derivatives exhibit pharmacological activities such as antimicrobial, antiviral, anticancer, anti-inflammatory, and neurotropic, psychoactive, and analgesic properties. The synthesis of drugs with high pharmaceutical properties and the creation of new generations of drugs using new benzimidazole derivatives is currently one of the most important areas of the modern pharmaceutical industry. Purpose of the study: Synthesis of a new coordination compound involving cobalt (II) and 1H-benzimidazole-2-carboxylic acid (1H-BIZ). Materials and methods: Differential thermal analysis (DTA) was used to determine the thermal stability and composition of the resulting complex compound. Results: To synthesize the complex compound, the masses of metal and ligand were taken in a 1:2 ratio. A 96 percent solution of ethanol was used as the solvent. The mixture was stirred regularly for 3-4 hours and stored in a dark place to dry. After a week, blue crystals formed. Analysis of the dynamic thermogravimetric analysis (DTGA) curve of the complex [Co(C8H5N2O2)2(C7H6N2)2] shows that the DTGA curve mainly occurs between 3 intense decomposition temperatures. The 1st decomposition step occurred in the temperature range of 125250°C, with a mass loss of 0.266 mg (4.46%). In this case, the decomposition of the water of crystallization contained in the complex compound was observed. The main decomposition occurred in the 2nd range at 250-330°C (strong exothermic peak in DSC), with the largest mass loss of 1.524 mg (25.75%). In addition, decomposition in small ranges corresponds to temperatures of 330-550°C, with a mass loss of 13.2%. The third decomposition range includes 550-680°C, and the mass loss in this range is 14.2%. Dervatographic studies show that the main mass loss occurs in the range of 125680 °C, with 99% of the main mass being lost. At the end of the analysis, the residual mass consists of CoO and other inorganic decomposition products, accounting for 12.96% of the total mass. 384 Volume 5, Issue 10: Special Issue (EJAR) ISSN: 2181-2020 MPHAPP THE 6TH INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “MODERN PHARMACEUTICS: ACTUAL PROBLEMS AND PROSPECTS” TASHKENT, OCTOBER 17, 2025 in-academy.uz Conclusions: The thermal stability of the synthesized complex was determined by thermogravimetry. Endoand exo-effects were discovered and thermal destruction products were identified, and it was shown that the thermal decomposition of complexes proceeds in several stages, including combustion of the organic part of the molecule, decomposition of the salt, oxidation of the decomposition products, and the formation of a metal oxide.