HIRSHFELD SURFACE ANALYSIS OF THE COMPLEX FORMED BY Cu (II) NITRATE WITH 1-ETHYL-2- (ETHYLTHIO) -1H-BENZO[d]IMIDAZOLE

325 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 HIRSHFELD SURFACE ANALYSIS OF THE COMPLEX FORMED BY Cu (II) NITRATE WITH 1-ETHYL-2- (ETHYLTHIO) -1H-BENZO[d]IMIDAZOLE Kurbanbaeva G.K. Raxmonova D.S. National University of Uzbekistan, Tashkent city, Republic of Uzbekistan e-mail: [email protected] https://doi.org/10.5281/zenodo.17336951 The relevance of the research: Hirschfeld surface analysis is a method that enables a more analytical study of intermolecular interactions. This analytical technique allows for the investigation and visualization of the size, shape, quality, and quantity of intermolecular contact surfaces in molecular crystals. The purpose of the research: [Cu(L)2(NO3)2] kompleks birikma tarkibidagi molekulalararo o‘zaro ta’sirlarni va ikki o‘lchovli barmoq izlari maydonlarini vizuallashtirish maqsadida Crystal Explorer 17,5 dasturi yordamida Xirshfeld yuzasini tahlil qilish. Methods and techniques: Study of Hirshfeld surface analysis. Results: The dnorm (Figure 1) for the [Cu(L)2(NO3)2] complex molecule was calculated using standard high surface precision. a b Figure 1. Hirshfeld surface according to dnorm (a) and two-dimensional fingerprint plots (b) showing the percentage contributions of all interactions for the [Cu(L)2(NO3)2] complex Analysis of two-dimensional fingerprint region plots reveals that the interactions H∙∙∙H (43.0%), C∙∙∙H/H∙∙∙C (13.3%), and O∙∙∙H/H∙∙∙O (29.7%) make the greatest contribution to the Hirshfeld surface. The largest portion of the total surface area is occupied by H∙∙∙H interactions, which result from the interaction between hydrogen atoms in the benzene ring and the methyl group. The greatest contribution of the O∙∙∙H/H∙∙∙O effect is explained by the abundance of intermolecular and intramolecular hydrogen bonds. Also, the contribution of the effects of N∙∙∙C/C∙∙∙N (1.0%) and C∙∙∙C/C∙∙∙C (3.0%) shows a smaller share. This ensures easy and quick comprehension of intermolecular interactions in Hirschfeld surface analysis. Figure 2. Interaction distances of individual atoms in the crystal structure of the [Cu(L)2(NO3)2] complex (two-dimensional fingerprint areas and their relative ratio at the Hirschfeld surface) Conclusion: To calculate the Hirschfeld surface, SIF files were processed in the Crystal Explorer 17.5 program to view intermolecular interactions in complex compounds. Expected bright H∙∙∙H 43,0% С∙∙∙N/N∙∙∙C 1,0% O∙∙∙H/H∙∙∙O 29,7% С∙∙∙H/H∙∙∙C 13,3% С∙∙∙C 3,0% 326 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 red spots near atoms participating in hydrogen bonds according to dnorm are shown on the Hirschfeld surface. Fingerprint drawings show the ratio of various interactions (types of hydrogen bonds) on the surface.