Hydrogen Bonds in the Formation of Copper(ii) 1,10-Phenanthroline Hydroxycarboxylatogermanate Crystals Using Hirshfeld Surface Analysis

Abstract

This article is dedicated to the investigation of crystalline structure in the complex cation-anionic compounds Cu(Phen)2Cl]2[Ge(HCit)2]⋅6H2O (I), [Cu(Phen)3]2[Ge2(OH)(HTart)(μ-Tart)2]·11H2O (II), [CuCl(Phen)2]4[{Ge2(OH)2(μ-Tart)2}Cl2]·4Н2О (III), [Cu(Phen)3]2[(OH)2Ge2(μ-HXylar)4Ge2(μ-OH)2]·8H2O (IV), [CuCl(Phen)2]4[(OH)2Ge2(μ-HXylar)4Ge2(μ-OH)2]·8H2O (V) using Hirshfeld surface analysis. This method has showed itself as an effective tool for analysis of intermolecular interactions, such as hydrogen bonds or weaker C…H and С…Н…p connections. Three-dimensional picture of close interactions in the crystal was built for each of the compounds I–V, where short connections are red-colored, while others – weaker and shorter – are light areas and small spots. It was established that in the structures of all compounds different types of hydrogen bonds are presented: bifurcate connections, symmetrical О-Н…О, С-Н…С and asymmetrical ones with water molecules. Two-dimensional histograms – 2D-fingerprint plots, allowed to evaluate quantitively connections in the crystals and establish that H…O/O…H and H…H interactions make the biggest contribution to the total surface area. The presence of the big number of crystallization water molecules is determinant for the formation of complex system of hydrogen bonds and strengthening of the structure, that otherwise would be unstable because of the big size of cations and anions. Due to the fact, that all compounds have the same complexing agent Ge(IV), structure of the anion is determined by polydentate ligand. Obtained results are important for the further development of the water role in the processes of crystallization, crystal formation, electrical dissociation and, especially, dissolving of coordination compounds in biological systems.

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“…In the framework of this study, compounds that include two diff erent metals with unlike coordination shells and consist of separate cations and anions are considered the most perspective due to the synergism of their components and variability of action mechanisms [12,13]. Previously the authors have developed a novel synthesis strategy that involves a combination of essential Ge(IV) with tartaric acid as an anion and Fe(II)/ Co(II)/ Ni(II)/ Cu(II) with biologically active 1,10-phenanthroline/2,2ʹ-bipyridine as a cation, which form double coordination compounds using electrostatic, π-π stacking in-teractions and hydrogen bonds [14][15][16][17][18]. Germanium is characterized by anticarcinogenic, antimicrobial, and antioxidant activities and plays an important role in oxygen transfer, while dicarbonic dihydroxy tartaric acid (H 4 Tart) is a strong chelating agent, widely used in the food industry and pharmacy [19,20].…”

“…Th e studied double complex compounds were obtained for the fi rst time in the form of crystal hydrates from an aqueous-alcoholic solution according to the reaction scheme (Fig. 1) and were described in detail by X-Ray, MS, IR, TG, elemental analysis in the articles [14][15][16][17][18]. Structural data were specifi ed at the Cambridge Crystallographic Data Center (CCDC) under the numbers 1964599 (1), 1964598 (2), 1878102 (3), 1878103 (4), 1883675 (5), 1883676 (6), 1576554 (7), and 1964600 (8).…”

HIRSHFELD SURFACE ANALYSIS OF CRYSTALS OF COMPLEXES - PRODUCTS OF REACTION IN SYSTEMS МХ2 – 1,10-PHENANTHROLINE – GeO2 – CITRIC ACID (М = Ni, Co; X = Cl, CH3COO)

“…В ході систематичного дослідження на кафедрі прикладної хімії та хімічної освіти ОНУ імені І. І. Мечникова було синтезовано ряд різнометальнозмішанолігандних комплексів германію(IV) та 3d-металів з лимонною кислотою та 1,10-фенантроліном [8][9][10][11][12][13], для комплексів купруму та цинку було встановлено особливості міжмолекулярних взаємодій методом поверхонь Хіршфельда [12,13].…”