Germanium Compounds Research Articles

Organogermanium(IV) complexes with O,N,O’-tridentate Schiff bases: synthesis, electrochemical transformations, photophysical properties, and anti/prooxidant activity

A series of novel diorganogermanium(IV) complexes of the type [R2Ge(Ln)] (where R is Et, Ph) with O,N,O’-tridentate redox-active Schiff bases has been synthesized. Compounds 1–7 were characterized by 1H, 13C{1H} NMR, IR spectroscopy, and elemental analysis. The molecular structures of complexes 1, 3, and 7 in crystal state have been established using single-crystal X-ray analysis. The complexes are pentacoordinate mononuclear compounds of germanium(IV). The bond lengths in tridentate ligands correspond to their diamagnetic dianionic forms. The electrochemical properties of complexes 1–7 were studied by cyclic voltammetry. A feature of the electrochemical behavior of target complexes is the ability to form relatively stable reduced/oxidized species as a result of the one-electron transfer. The stability of electrogenerated forms is influenced by both the organic groups at the germanium(IV) atom and the substituents in the Schiff bases. The energy gap (ΔEel) between the boundary redox orbitals obtained from electrochemical data for the complexes varies from 2.43 to 2.60 eV, while the optical ΔE was observed in the narrow range (2.46 – 2.50 eV). Luminescent activity was detected for some complexes in the solution. The maximal values ​​of the relative quantum yield were determined for complexes containing an electron-withdrawing nitro group in the redox-active ligand. In the reaction with ABTS radical cation, compound 1 only possessed the radical scavenging activity while the other compounds are characterized by weak neutralizing properties. The dual anti/prooxidant action was observed for compounds 1–7 in the process of rat liver (Wistar) homogenate lipid peroxidation.

Main Group Metal Complexes of Si, Ge and Al with an Unsymmetrical N,N’‐substituted Diamide Ligand

Unsymmetrically N,N’‐substituted metal amides of silicon, germanium and aluminium were synthesized starting from N‐ethyl‐2‐(n‐propylaminomethyl)­phenyl­amine (1, Et,nPr‐ampaH2). Reaction of the dilithium compound of 1 with SiCl4 gave spirocyclic Si(Et,nPr‐ampa)2 (2) and Cl2Si(Et,nPr‐ampa) (3). Reduction of 3 with potassium resulted in the formation of the corresponding cyclotetrasilane [Si(Et,nPr‐ampa)]4 (4), whereas the reaction of 3 with lithium triethylborohydride gave the dihydro silane H2Si(Et,nPr‐ampa) (5). The corresponding germanium(IV) compounds Ge(Et,nPr‐ampa)2 (6) and Cl2Ge(Et,nPr‐ampa) (7) were synthesized starting from GeCl4, amine 1 and NEt3 using appropriate stoichiometric ratios. Reaction of Ge[N(SiMe3)2]2 with amine 1 provided the germylene [Ge(Et,nPr‐ampa)]2 (8). The aluminium dichloro compound Cl2Al(Et,nPr‐ampaH) (9) was obtained either by reaction of the dichlorogermine 7 with lithium aluminium hydride or by reaction of the dilithium salt of 1 with AlCl3. Reaction of trimethylaluminium with amine 1 provided the amido‐amine (CH3)2Al(Et,nPr‐ampaH) (10) which was converted into the diamide CH3Al(Et,nPr‐ampa) (11) by methane elimination.

Synthesis, Structure, Electrochemical Properties, and Antioxidant Activity of Organogermanium(IV) Catecholate Complexes.

A series of novel organogermanium(IV) catecholates 1-9 of the general formula R'2Ge(Cat), where R' = Ph, Et, have been synthesized. Compounds were characterized by 1H, 13C NMR, IR spectroscopy, and elemental analysis. The molecular structures of 1-3, 6, and 8 in crystal state were established using single-crystal X-ray analysis. The complexes are tetracoordinate germanium(IV) compounds containing a dioxolene ligand in a dianion (catecholato) form. Electrochemical transformations of target germanium(IV) complexes have been studied by cyclic voltammetry. The electro-oxidation mechanism of complexes 1-5, 7, and 10 (the related complex Ph2Ge(3,5-Cat) where 3,5-Cat is 3,5-di-tert-butylcatecholate) involves the consecutive formation of mono- and dicationic derivatives containing the oxidized forms of redox-active ligands. The stability of the generated monocations depends both on the hydrocarbon groups at the germanium atom and on the substituents in the catecholate ring. Compounds 6, 8, and 9 are oxidized irreversibly under the electrochemical conditions with the formation of unstable complexes. The radical scavenging activity and antioxidant properties of new complexes were estimated in the reaction with DPPH radical, ABTS radical cation, and CUPRACTEAC assay. It has been found that compounds 8 and 9 with benzothiazole or phenol fragments are more active in DPPH test. The presence of electron-rich moieties in the catecholate ligand makes complexes 5 and 7-9 more reactive to ABTS radical cation. The value of CUPRACTEAC for organogermanium(IV) catecholates varies from 0.23 to 1.45. The effect of compounds 1-9 in the process of lipid peroxidation of rat liver (Wistar) homogenate was determined in vitro. It was found that most compounds are characterized by pronounced antioxidant activity. A feature of complexes 1, 3, and 5-9 is the intensification of the antioxidant action with the incubation time. In the presence of additives of complexes 3, 5, 6, and 8, an induction period was observed during the process of lipid peroxidation.

Topological Transformation of Hydrogen-Terminated Germanium to Germanium Nanosheets for Fast Lithium Storage.

Germanium has been recognized as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and excellent lithium-ion diffusivity. Nonetheless, it is challenging to enhance both the high-rate performance and long-term cycling stability simultaneously. This study introduces a novel heterostructure composed of germanium nanosheets integrated with graphene (Ge NSs@Gr). These nanosheets undergo an in situ phase transformation from a hydrogen-terminated multilayer germanium compound termed germanane (GeH) derived via topochemical deintercalation from CaGe2. This approach mitigates oxidation and prevents restacking by functionalizing the exfoliated germanane with octadecenoic organic molecules. The resultant germanium nanosheets retain their structural integrity from CaGe2 and present an exposed, active (111) surface that features an open crystal lattice, facilitating swift lithium-ion migration conducive to lithium storage. The composite material delivers a substantial reversible capacity of 1220 mA h g-1 at a current density of 0.2 C and maintains a capacity of 456 mA h g-1 even at an ultrahigh current density of 10 C over extended cycling. Impressively, a capacity of 316 mA h g-1 remains after 5000 cycles. The exceptional high-rate performance and durable cycling stability underscore the Ge NSs@Gr anode's potential as a highly viable option for LIBs.

Sterically Crowded Gold Germylene Compounds with Methyl and Hydride Substituents

AbstractThis work explores the combination of sterically crowded low‐valent germanium compounds bearing one or two terphenyl (C6H3‐2,6‐Ar2) substituents with gold fragments, the latter stabilized by crowded phosphines also containing a terphenyl moiety. The steric protection of these motifs has allowed to examine a series of unusual gold‐germylene compounds featuring small hydride and methyl substituents at the germanium site. A gold‐germylene dicationic structure is also reported. The bonding in this series is investigated by computational means, providing understanding for the two‐way transfer of electrons from germanium to gold and vice versa.

Reversible Coupling of Germylone with Isocyanates.

The germylone dimNHCGe (5, dimNHC=diimino N-heterocyclic carbene) undergoes a [2+2] cycloaddition with isocyanates RNCO (R=4-tolyl or 3,5-xylyl) to furnish novel alkyl carboxamido germylenes 7 (R=4-tolyl) and 8 (R=3,5-xylyl), featuring a C-C bond between the former carbene carbon and the isocyanate moiety. Heating a mixture of 8 with 4-tolyl isocyanate to 100 °C results in isocyanate metathesis, demonstrating reversible C-C bond formation on the reduced germanium compound. DFT calculations suggest that this process occurs via the reductive dissociation of isocyanate from 8 that regenerates the parent Ge(0) compound 5.

Synthesis, Structure, and Biological Activity of the Germanium Dioxide Complex Compound with 2-Amino-3-Hydroxybutanoic Acid

Currently, a promising direction of study is the use of biologically active coordination compounds in the pharmacopoeia and the creation of effective bactericidal drugs, biomaterials, and enzyme modulators on that basis. The paper considers a coordination germanium compound with 2-amino-3-hydroxybutanoic acid. The prospects for the use of the compound in medicine are outlined. This work is aimed at solving the problems regarding the synthesis of biologically active compounds with a wide spectrum of actions. The structure and composition of the coordination compound have been established through calculation and experimental methods. The biocidal (bactericidal and fungicidal) activity of germanium-containing compounds against a number of bacteria and microscopic fungi has been studied. Using the quantum-chemical method with density functional theory (DFT, B3LYP/6–311++G(2d,2p)), the theoretical IR spectrum of the compound was calculated. The structure of the coordination compound and the structure of the intermediates at all stages of the synthesis process were established by calculation.

Small-Molecule Activation by Low-Coordinated Germanium Compounds

AbstractWe have been interested in the differences between the properties of low-coordinated carbon compounds and their heavier homologues based on elements of group 14, e.g., Si and Ge. Fundamental research on the synthesis and characterization of divalent and multiply bonded compounds of heavier group 14 elements has led to a variety of isolated low-coordinated species of heavier group 14 elements that can replace transition metals in small-molecule transformations. We have focused on low-coordinated germanium compounds with double or triple bonds between germanium atoms, as well as germanium-containing aromatic compounds. Once isolated, the reactivity of these low-coordinated germanium compounds was examined with regard to small-molecule activation. In this account, the reactivity patterns of these compounds will be described.1 Introduction2 1,2-Dibromodigermenes and Bromogermylenes3 Digermynes4 1,2-Digermacyclobutene5 1,3-Digerma-2-silaallene6 Digerma-Aromatic Compounds7 Germanium-Catalyzed Cyclotrimerization of Alkynes8 Summary

Amidinatotetrylenes Donor Functionalized on Both N Atoms: Structures and Coordination Chemistry.

E(hmds)(bqfam) (E = Ge (1a), Sn (1b); hmds = N(SiMe3)2, bqfam = N,N'-bis(quinol-8-yl)formamidinate), which are amidinatotetrylenes equipped with quinol-8-yl fragments on the amidinate N atoms, have been synthesized from the formamidine Hbqfam and Ge(hmds)2 or SnCl(hmds). Both 1a and 1b are fluxional in solution at room temperature, as the E atom oscillates from being attached to the two amidinate N atoms to being chelated by an amidinate N atom and its closest quinolyl N atom (both situations are similarly stable according to density functional theory calculations). The hmds group of 1a and 1b is still reactive and the deprotonation of another equivalent of Hbqfam can be achieved, allowing the formation of the homoleptic derivatives E(bqfam)2 (E = Ge, Sn). The reactions of 1a and 1b with [AuCl(tht)] (tht = tetrahydrothiophene), [PdCl2(MeCN)2], [PtCl2(cod)] (cod = cycloocta-1,5-diene), [Ru3(CO)12] and [Co2(CO)8] have been investigated. The gold(I) complexes [AuCl{κE-E(hmds)(bqfam)}] (E = Ge, Sn) have a monodentate κE-tetrylene ligand and display fluxional behavior in solution the same as that of 1a and 1b. However, the palladium(II) and platinum(II) complexes [MCl{κ3E,N,N'-ECl(hmds)(bqfam)}] (M = Pd, Pt; E = Ge, Sn) contain a κ3E,N,N'-chloridotetryl ligand that arises from the insertion of the tetrylene E atom into an M-Cl bond and the coordination of an amidinate N atom and its closest quinolyl N atom to the metal center. Finally, the binuclear ruthenium(0) and cobalt(0) complexes [Ru2{μE-κ3E,N,N'-E(hmds)(bqfam)}(CO)6] and [Co2{μE-κ3E,N,N'-E(hmds)(bqfam)}(μ-CO)(CO)4] (E = Ge, Sn) have a related κ3E,N,N'-tetrylene ligand that bridges two metal atoms through the E atom. For the κ3E,N,N'-metal complexes, the quinolyl fragment not attached to the metal is pendant in all the germanium compounds but, for the tin derivatives, is attached to (in the Pd and Pt complexes) or may interact with (in the Ru2 and Co2 complexes) the tin atom.

Synthesis and Reactivity of Fluorenyl-Based Germanium(II) Compounds.

We present the synthesis of alkyl-substituted germylenes GeFlu2, Ge(FluTMS)2, and FluTMSGeCl (Flu = 9H-fluorenyl, FluTMS = 9-trimethylsilyl-9H-fluorenyl) using bulky fluorenyl ring systems and modifications of that. GeFlu2 can only be crystallized as its three-membered ring trimer, whereby the reaction is accompanied by the formation of several byproducts, such as [Li(THF)4][Ge(Ge3Flu7H)]. These results led to the modification of the fluorenyl framework by substitution the one H atom in the 9-position by a TMS group. With the synthesis of the corresponding Li salt LiFluTMS, Ge(FluTMS)2 could be isolated in good yields in a further reaction. The homoleptic Ge(FluTMS)2 is found in its crystalline form as a monomer and thus belongs to the series of monomeric alkyl-substituted germylenes. Also, the corresponding monoalkyl-substituted halogenido germylene was isolated as a four-membered ring tetramer [FluTMSGeCl]4 during an unselective reaction. However, FluTMSGeCl undergoes significant stabilization through the formation of the monomeric phosphane adduct FluTMSGeCl·PEt3, which greatly increases the selectivity of the reaction. During further reactions of Ge(FluTMS)2 with a GeBr solution (toluol/nPr3P), more impressions of the reactivity of Ge(I)X solutions with germylenes were achieved, showing that those germylenes take part in the disproportionation reaction of metastable Ge(I) solutions to give oxidized Ge(IV) compounds like (FluTMS)2GeBr2.

Hypercoordinated germanium complexes with ligands containing hydroxyalkyl groups

Among germatranes, 1-germatranol hydrate is the most well-studied compound with a diverse spectrum of biological activity. Its synthesis is based on a one-stage reaction of tris(2-hydroxyethyl)amine with germanium dioxide in an aqueous medium without the use of organic solvents. In this work, taking into account this approach, new potentially biologically active compounds of germanium with hydroxyalkylamines, sulfo- and amino acids containing hydroxyalkyl groups were synthesized, which we considered as new analogues of biologically active 1-germatranol hydrate. Their formation is confirmed by the results of elemental analysis, IR and NMR spectroscopy. In silico ADME and Pass analysis were used to assess the potential bioavailability and pharmacological activity profile of new compounds. The results of an in vitro study of the antiviral activity (influenza A/Aichi/2/68 (H3N2) virus) of synthesized compounds are presented.

The influence of iron and germanium nanocompounds on the content of ceruloplasmin in the blood of sows and piglets obtained from them

The work is devoted to establishing the degree and nature of the effect of the application of iron and germanium nano compounds on the content of ceruloplasmin in the blood plasma of sows and piglets obtained from them. For this, two groups of sows (control and experimental) were selected; the pigs of the experimental group were given a complex of nano compounds of trace elements iron and germanium, and the ceruloplasmin content in the blood was evaluated. A reliable effect of the application of iron and germanium nanocompounds on the content of ceruloplasmin in the blood of sows was established – F = 25.5 > FU = 4.15; P < 0.001, which is manifested only after farrowing – gh²ᵪ = 0.48–0.74 (P ≤ 0.05–0.01). Thus, after farrowing (on the first and third day), the content of the enzyme in the blood of these animals was significantly higher than that of sows of the control group (12.7–13.5 %; P ≤ 0.05). It was established that the ceruloplasmin content in the blood of piglets obtained from sows that were given the mentioned metal nanocompounds on the second (gh²ᵪ = 0.52; P ≤ 0.05) and seventh (gh²ᵪ = 0.70; P ≤ 0.01) days of life of animals depends on the application of iron and germanium nanocompounds. In these piglets, the enzyme content two and seven days after birth is 13.3–20.0 % (P ≤ 0.05) higher than piglets obtained from sows that were not given nanocompounds. It was experimentally proven that the content of ceruloplasmin in the blood plasma of piglets obtained from sows that were given nano compounds of metals is directly related to its content in the blood of sows, in particular, the content of the enzyme in the blood of two- and 7-day-old piglets correlates with the content of the enzyme in the blood of sows on the day of farrowing – r = 0.91–0.95 (P ≤ 0.001). Therefore, the conducted studies indicate the effectiveness of using ferrum and germanium nanoparticles to correct the ceruloplasmin content in the blood of both sows and suckling piglets.

Migration behavior of germanium and its related elements in zinc hydrometallurgy process

Lead-zinc sulfide ore is one of the raw materials for the recovery of strategic germanium resources. Due to the complexity of its mineralization and the diversity of elements, the occurrence and migration of germanium and its related elements in the process of zinc hydrometallurgy is still a mystery. This leads to the recovery efficiency of germanium is always in a disappointing state, which seriously reduces the economic benefits and resource recovery rate in the process of germanium recovery, and limits the development of some cutting-edge industries. Therefore, in view of the above problems, based on the properties of germanium compounds in lead–zinc sulfide minerals, this study analyzed the occurrence state and quantity of germanium in the products of each stage in the process of zinc hydrometallurgy by ICP, XRD, FT-IR, SEM, XPS, Raman spectrum and TG, so as to reveal the reaction behavior and migration law of germanium compounds in the process of zinc hydrometallurgy. The results indicate show that the two roasting will lead to the mutual transformation of GeO2 crystal form between soluble and insoluble, especially in the process of reduction and volatilization of zinc leaching residue. The phenomenon of soluble GeO2 to insoluble GeO2 is particularly significant, and the germanium-containing silicate cannot be reacted in the whole process. In addition, zinc blende, zinc ferrite, tin dioxide and other substances that exhibit isomorphism with germanium compounds will carry germanium into lead slag due to their low solubility. Finally, in view of the problems existing in the current germanium recovery process, positive solutions are proposed to introduce green additives in the two roasting stages to improve the phase of germanium, and to add oxidants or reducing agents in the leaching stage.

State of peroxidation in the brain and liver in experimental diabetes and its correction possibility with niacin-oxyethylendiphosphonatogermanate

The development of pharmacological methods to control oxidant stress manifestations in diabetes can be achieved using organic complex germanium compounds. One of the promising compounds is niacin-oxyethylenediphosphonategermanate (MIGU-4), which is an effective corrector of lipid metabolism and a stabilizer of the lipid layer of erythrocyte and hepatocyte membranes in the streptozotocin-induced diabetic model. The aim of the work is to determine the dynamics of the malondialdehyde (MDA) content, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPO) in the brain tissue, as well as the diene conjugate (DC) content, lipid hydroperoxides (LHP), reduced glutathione (GSH) in the liver mitochondria, the serum activities of aspartate and alanine aminotransferases (AST and ALT) in experimental diabetes mellitus with the correction using a complex compound of germanium with nicotinic acid – MIGU-4 and insulin, insulin alone as well as in comparison with effectiveness of vitamin E supplementation. Materials and methods. Diabetes was induced in male Wistar rats by intraperitoneal injection of streptozotocin (60.0 mg/kg). MIGU-4 was administered intraperitoneally at a dose of ED50 that was 25.0 mg/kg. Mitochondrial membranes were obtained by differential centrifugation of the liver tissue. In rats with confirmed diabetes, parameters of peroxidation and antioxidant protection were studied by generally accepted biochemical and biophysical methods. Results. Glucose levels were 29.4 % lower in rats treated with MIGU-4 (25.0 mg/kg) after 8 weeks of streptozotocin-induced diabetes than those in untreated diabetic rats (p < 0.05), while a decrease was 39.0 % (p < 0.05) upon insulin treatment, and 47.2 % (p < 0.05) – with combined use of the drugs. The MDA content in the brain tissue was 3.48 times higher than that in the control (p < 0.05). At the same time, the activities of SOD and CAT were decreased by 46.4 % and 32.0 %, respectively, the activity of GPO was decreased by half (p < 0.05). In the liver mitochondria, the DC content exceeded that in the control by 53.5 % (p < 0.05), and the MDA and LHP levels were 2.48 times and 31.7 % higher (p < 0.05), respectively. AST activity was almost doubled, ALT activity was 5.48 times increased. Insulin and the biologically active substance MIGU-4 used alone exerted a moderate corrective effect. The combined use of the drugs caused definite therapeutic and preventive effects as the brain content of MDA was 2.4 times decreased, the activity of SOD, CAT and GPO was increased by 45.6 %, 35.2 % and 67.3 % (p < 0.05), respectively. In the liver mitochondria, the DC, MDA, and LHP contents were decreased by 41.0 %, 53.3 %, and 28.4 %, respectively, compared to those in rats with diabetes (p < 0.05). The activity of SOD and CAT as well as GSH content were increased by 2.7 times, 51.9 %, and 23.0 % (p < 0.05), respectively. AST and ALT activities were 42.2 % and 74.3 % (p < 0.05) reduced, respectively. The combined use of MIGU-4 (25.0 mg/kg) and vitamin E (250.0 mg/kg) caused a decrease in the brain MDA content by 70.1 % (p < 0.05) in experimental rats. The combination of MIGU-4 and vitamin E increased the activity of GPO by 58.3 % (p < 0.05) as compared to rats with diabetes, indicating cumulative effects of these drugs. Conclusions. The use of MIGU-4 prevents the occurrence of oxidant stress manifestations in the brain tissue and liver mitochondria in streptozotocin-induced diabetes. The corrective effect size of MIGU-4 (25.0 mg/kg) corresponds to that of vitamin E (250.0 mg/kg).

Germanium: distribution, migration and accumulation in the natural environment

In this paper we attempt to generalize information published in the scientific literature about the distribution, migration and accumulation of chemical forms of germanium in the natural environment, with the main attention paid to the content of this trace element in various components of the environment. Despite the fact that germanium is found in the lithosphere, hydrosphere and atmosphere it is one of the least studied elements in mineral and geochemical terms. It belongs to rare scattered elements with a relatively high migration capacity in the earth's crust and on its surface. Depending on the physical and chemical conditions, the mineral and lithogenesis of germanium can exhibit different properties, which determines the variety of ways of its migration. The nature and form of migration of germanium in the natural environment is not determined only by its chemical properties but also by a complex set of reactions of interaction with various underground water addendums, the granulometric and chemical-mineralogical composition of soil-forming rocks and soils, biogenic and technogenic processes. Studies have shown that the content of germanium in natural waters, soils and plants can vary widely and depends on many factors. In particular, its concentration in groundwater and surface water depends on the natural geological environment, pressure, temperature, meteorological and anthropogenic factors; soil by their type, region, features of soil-forming processes, chemical composition of the parent rocks, climatic conditions and amounts of organic substances; in plants by their species and varietal facilities, the growth stage of the plants, the availability of soils by this element, the forms of germanium compounds in the soil (inorganic or organic), the ability of soil to retain labile form of germanium and climatic conditions. Analysis of the actual content of germanium in diets indicates an insufficient level of provision of the human body with this trace element, due to its low concentrations in food and water. However, it has been suggested that any products with a high content of germanium may pose a risk to human health through its toxic effects.

GeCn Coordination Polyhedra in the Crystal Structures

A crystal-chemical analysis has been performed for germanium compounds whose structure includes GeCn coordination polyhedra using the intersecting sectors method and Voronoi–Dirichlet polyhedra. In the structures of organogermanium compounds, the germanium atoms have coordination numbers of 2–6 and 10 with respect to the carbon atoms. The influence of the coordination number and oxidation state of germanium atoms on the main characteristics of their Voronoi–Dirichlet polyhedra (VDP) was considered. The existence of a single linear dependence of the solid angles of VDP faces corresponding to valence and nonvalence Ge–C and Ge⋅⋅⋅C contacts on the corresponding internuclear distances was established. A stereo effect of the lone pair of electrons of Ge(II) atoms in the GeCn complexes (n = 2–6 or 10) found; it manifests itself as a displacement of the nuclei of Ge(II) atoms from the centers of gravity of their VDPs (0.15–0.58 Å) and as asymmetry of the coordination sphere. The deviation of the GeC3 complexes from planar geometry in the crystal structures was shown to be directly proportional to the displacement of the nuclei of Ge atoms from the centers of gravity of their VDP.

Hexacoordinate germanium compounds with BIS-TRIS and amino acid ligands

New germanium-containing compounds of the atrane family have been synthesized by reacting germanium glycinate, L-α-alaninate and L-valinate with [bis(2-hydroxyethyl)-amino][tris(hydroxymethyl)]methane (BIS-TRIS) and explored by FT-IR, NMR spectroscopy, thermal and elemental analysis. The fully local meta-GGA correlation functional (M06-L) was applied to investigate their equilibrium geometries. The derivatives of BIS-TRIS and triethanolamine have been investigated by computational screening via ADMET and PASS software.

Activation of the Olefinic C–H Bond of NHC and NHO by Perimidine-Based Silicon and Germanium Compounds

Activation of the Olefinic C–H Bond of NHC and NHO by Perimidine-Based Silicon and Germanium Compounds

Physiological Activity of Trace Element Germanium including Anticancer Properties.

Germanium is an essential microelement, and its deficiency can result in numerous diseases, particularly oncogenic conditions. Consequently, water-soluble germanium compounds, including inorganic and coordination compounds, have attracted significant attention due to their biological activity. The review analyzes the primary research from the last decade related to the anticancer activity of germanium compounds. Furthermore, the review clarifies their actual toxicity, identifies errors and misconceptions that have contributed to the discrediting of their biological activity, and briefly suggests a putative mechanism of germanium-mediated protection from oxidative stress. Finally, the review provides clarifications on the discovery history of water-soluble organic germanium compounds, which was distorted and suppressed for a long time.

Robert C. West (1928–2022): A Giant in Organosilicon Chemistry, Cosmopolitan, Mountain Climber and Pilot

Robert C. West (1928–2022): A Giant in Organosilicon Chemistry, Cosmopolitan, Mountain Climber and Pilot