0022-4766/20/6109-1315 © 2020 by Pleiades Publishing, Ltd. 1315 ISSN 0022-4766, Journal of Structural Chemistry, 2020, Vol. 61, No. 9, pp. 1315-1355. © Pleiades Publishing, Ltd., corrected publication 2020. Russian Text © The Author(s), 2020, published in Zhurnal Strukturnoi Khimii, 2020, Vol. 61, No. 9, pp. 1389-1432. ANALYSIS OF XRD STRUCTURAL PARAMETERS OF GLYCOLURIL AND ITS DERIVATIVES* S. Yu. Panshina 1,2 **, O. V. Ponomarenko 3 , A. A. Bakibaev 1 , and V. S. Malkov 1 The paper discusses the results of X-ray diffraction studies of 2,4,6,8-tetraazabicyclo[3.3.0.]octane-3,7- dione (glycoluril) and its derivatives. Geometrical characteristics of glycoluril derivative molecules are analyzed depending on the type of the substituent and the formation of hydrogen bonds in crystals. DOI: 10.1134/S0022476620090012 Keywords: XRD analysis, glycoluril, hydrogen bonds, alkyl glycolurils, acetyl glycolurils, phenyl glycolurils, metal complexes, bond lengths, dihedral angles. INTRODUCTION Due to their framework structure, bicyclic bisureas of the octane series (glycolurils) have been used to create valuable substances applicable to various human activities: disinfectants [1, 2], medications [3, 4], polymer stabilizers [5], explosives or their components [6-8], and other important substances and materials. In fact, geometrical characteristics of glycolurils made it possible to synthesize and study glycoluril based supramolecular compounds. It was established in the course of these studies that glycolurils are building units in polycyclic condensed systems such as cucurbit[n]urils [9-11] and bambus[n]urils [12, 13] possessing a number of unique physical and chemical properties. Studying the spatial arrangement of molecules formed as a result of intermolecular interactions and bond polarization in synthons often provides initial information on the organization of corresponding supramolecules. The data on the structure of molecular ensembles obtained from the crystalline structures of synthons are used to infer the structure of liquids and solutions, molecular clusters, and other supramolecular structures. Thus, the present work is devoted to the analysis of X-ray diffraction studies of 2,4,6,8- tetraazabicyclo[3.3.0.]octane-3,7-dione 1 (referred to below as glycoluril 1) and its derivatives 2-39 (see their general formula in the Table 1) and to the identification of structural characteristics of glycolurils 1-39, namely: the effect of substituents and their types on the geometry of molecules and the formation of hydrogen bonds in crystals, which ultimately determines the ability of glycolurils to form complexes, macro- and supramolecules. 1 National Research Tomsk State University, Tomsk, Russia; **janim_svetatusik@mail.ru. 2 Tomsk Polytechnic University, Tomsk, Russia. 3 Gumilyov Eurasian National University, Nur-Sultan, Republic of Kazakhstan. Original article submitted February 22, 2020; revised April 14, 2020; accepted April 15, 2020. * The supplementary materials for this article are available to authorized users at: doi 10.1134/S0022476620090012.