Supramolecular Salts of Germanium (IV) with Tartaric Acid, Zinc and 1,10‐Phenanthroline/2,2‘‐Bipyridine: Synthesis, Structural Features and Selective Recognition

Abstract

The study describes synthesis methods, structural features and thermal stability of the novel cation‐anionic coordination compounds, crystallized in Sohnke chiral space group P21 [Zn(phen)3]2[Ge2(OH)(HTart)(μ‐Tart)2] ⋅ 23H2O (1) and [Zn(bipy)3][Ge2(OH)2(μ‐Tart)2] ⋅ 5H2O (2). Dependently on the second heterocyclic ligand (1,10‐phenanthroline ‐ phen (1) or 2,2’‐bipyridine ‐bipy (2)) complex zinc cations showed their ability to recognize selectively two different types of anions: dimeric [Ge2(OH)2(μ‐Tart)2]2− (2) and more complex [Ge2(OH)(HTart)(μ‐Tart)2]4− (1) with additional terminal tartaric acid ligand (HTart3−) and different coordination polyhedrons of Ge in its structure. Compounds 1 and 2 were characterized by X‐Ray, IR, MS and thermogravimetric analyzes. Analysis of intermolecular interactions using Hirshfeld surface‐based tools indicated the dominant role of various hydrogen intermolecular interactions such as H…H, H…O for both compounds, and C…C (π⋅⋅⋅π) for 1.

Untitled

“…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).…”