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The field of organogermanium in chemistry has recently attracted attention. Thanks to the inherent features of germanium (Ge), introducing Ge‐based substituents into organic frameworks has enhanced bioactivity and optoelectronic properties of molecules. Herein, the synthesis of multi‐functionalized organogermaniums using Ge(II) salts is reported. The germacycles having an allylboron moiety, which is derived from the (4+1) cycloadditions of the butadienes bearing a boronic ester moiety with Ge(II) salts, can be applied to further allylboration of aldehydes with perfect diastereoselectivity. The obtained allylated adducts enable access to π‐extended organogermaniums with the retention of the stereocenters. [ABSTRACT FROM AUTHOR]

Porous organic polymers (POPs) as electrode materials for sodium‐ion batteries (SIBs) are attracting increasing attention. However, the application of porous organic radical polymers (PORPs) with unique properties in SIBs is still in an infancy. Herein, two 3D germanium‐based POPs with conjugated diacetylene units (Ge‐DA) and acetylene units (Ge‐A) are designed and synthesized. Carbon radicals in Ge‐DA are verified by electron paramagnetic resonance and the resonance structure is calculated by density functional theory, showing a lower lowest unoccupied molecular orbital (LUMO) energy level (−5.46 eV) and a narrow energy gap (ca. 1.64 eV). In contrast, Ge‐DA as an anode for SIBs shows superior electrochemical properties to that of Ge‐A counterpart, including a higher specific discharge capacity of 349 mAh g−1 at 200 mA g−1, excellent cyclability with a capacity of 112 mAh g−1 at 5 A g−1 for at least 5000 cycles and high rate performance of 135 mAh g−1 at 20 A g−1, proving that the different electronic structures of the diacetylene and monoacetylene units affect the properties of materials. [ABSTRACT FROM AUTHOR]

The low-valent germanium and tin hydrides, [LMH; L = {(ArHN)(ArN)-C＝N–C＝(NAr)(NHAr); Ar = 2,6-Et2-C6H3}; M = Ge; (Ge-1), Sn (Sn-2)] bearing bis-guanidinato anions are employed as catalysts for chemoselective reduction of heterocumulenes via hydroboration reactions. This protocol demonstrates that a wide range of carbodiimides (CDI), isocyanates, isothiocyanates, and isoselenocyanates undergo partial reduction, yielding the corresponding N-boryl formamidine, N-boryl formamide, N-boryl thioformamide, and N-boryl selenoformamide products, respectively. Isocyanates and isothiocyanates are further converted into N-boryl methyl amines through hydrodeoxygenation (HDO) and hydrodesulfurization (HDS) reactions in the presence of catalyst Ge-1. Additionally, catalyst Sn-2 exhibits excellent inter and intra-molecular chemoselectivity over other functional groups. Based on stoichiometric experiments, a plausible catalytic cycle for chemoselective hydroboration of heterocumulenes is proposed. [ABSTRACT FROM AUTHOR]

Germanium (Ge), a congener of carbon, possesses unique properties that hold extensive potential for applications across multiple domains. Recent years have seen significant progress in the development of carbon‐germanium bond formation strategies, particularly those for more challenging C(sp3)−Ge bonds. This review systematically summarizes the recent advances in C(sp3)−Ge bond forming methodologies, with particular emphasis on (1) the versatility of transition‐metals, including iron, nickel, copper, rhodium and palladium, as catalysts in broadening reaction scope and controlling selectivity; (2) the powerfulness of organic photocatalysis in achieving mild and selective bond formation, and (3) the sustainability of catalytic electrosynthesis in facilitating chemical oxidant‐/reductant‐ free conversions. Additionally, examples of (4) non‐catalytic strategies are also discussed. The representative scopes, as well as mechanistic proposals, of these protocols are highlighted. Through an overview on the current state of research, this review aims to offer insights into the catalytic construction of C(sp3)−Ge bonds, and provide perspectives on future research directions to address the current challenges. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) and the antioxidant germanium (Ge) are promising tools for boosting bioactive compound synthesis and producing healthier foods. However, their combined effect remains unexplored. This study demonstrates the synergistic impact of AMF and Ge on the growth, metabolite accumulation, biological activities, and nutritional qualities of Spinacia oleracea L. (spinach), a globally significant leafy vegetable. Individually, Ge and AMF increased biomass by 68.1% and 22.7%, respectively, while their combined effect led to an 86.3% increase. AMF and Ge also improved proximate composition, with AMF–Ge interaction enhancing crude fiber and mineral content (p < 0.05). Interestingly, AMF enhanced photosynthesis-related parameters (e.g., total chlorophyll) in Ge treated plants, which in turn increased carbohydrate accumulation. This accumulation could provide a route for the biosynthesis of amino acids, organic acids, and fatty acids, as evidenced by increased essential amino acid and organic acid levels. Consistently, the activity of key enzymes involved in amino acids biosynthesis (e.g., glutamine synthase (GS), methionine biosynthase (MS), lysine biosynthase (LS)) showed significant increments. Furthermore, AMF improved fatty acid levels, particularly unsaturated fatty acids in Ge-treated plants compared to the control. In addition, increased phenylalanine provided a precursor for the production of antioxidants (e.g., phenols and flavonoids), through the action of the enzyme phenylalanine ammonia-lyase (PAL), resulting in improved antioxidant activity gains as indicated by FRAP, ABTS, and DPPH assays. This study is the first to show that Ge enhances the beneficial effect of AMF on spinach, improving growth and nutritional quality, with promising implications for agricultural practices. [ABSTRACT FROM AUTHOR]

The particular reactivity of the recently discovered class of the main group element polyhedral clusters, pyramidanes, remains largely unexplored. In this communication, we report the reaction of the germapyramidane with tert‐butyllithium leading to the rather unusual organogermanium compound [Li+(thf)2]⋅2−, as the product of the formal insertion of a Ge‐apex into the C−Li bond. This reactivity mode exemplifies unusual electrophilic behaviour of a pyramidane, which is a priori considered as a nucleophilic reagent. Being highly reactive, [Li+(thf)2]⋅2− readily undergoes reactions with electrophiles (MeI, EtBr), initially forming intermediate germahousenes, which isomerize to the thermodynamically more favourable germoles. [ABSTRACT FROM AUTHOR]

The reactivity of an isolable 2‐germapropadiene with acids, ketones, and amines was investigated. The reactions of 2‐germapropagiene 1 with hydrogen chloride and acetic acid afforded the corresponding dichlorogermane (2) and diacetoxygermane (3), respectively, indicating that the central germanium atom of 1 is electrophilic. The reaction of 1 with benzaldehyde proceeds via a formal [2+2] cycloaddition to afford the corresponding spiro compound (4). Moreover, 1 reacts smoothly with acetone to furnish germane 5, which contains a six‐membered ring involving two acetone molecules. Furthermore, 1 undergoes N−H bond insertion with methylamine or aniline to afford diamino germanes 7 and 8, respectively. The reaction of 1 with urea selectively afforded the corresponding N−H−insertion product (8). [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii has emerged as a main nosocomial pathogen exhibiting high rates of resistance to clinically relevant antibiotics. Six pandrug-resistant A. baumannii (PDR-A. baumannii) were recovered from three patients in a Tunisian Intensive Care Unit (ICU) between 10th and 16th of May 2018 resulting in one fatal case and raising the possibility of an outbreak. On 18th of May environmental screening of ICU surfaces was carried out. On 22nd of May a fourth patient was infected with PDR-A. baumannii and died. A second investigation was carried out for environmental screening and PDR-A. baumannii was isolated from the respirator. Antimicrobial susceptibility testing was performed according to EUCAST (2019) guidelines. MIC of colistin was determined by broth microdilution method. PCR was used to detect 14 beta-lactamases/carbapenemases and mcr (mcr-1 to mcr-5) genes. The genetic relatedness of PDR-A. baumannii isolates was determined by PFGE and MLST. Seven PDR-A. baumannii isolates were recovered from four patients, one MDR strain from wash basin, a PDR strain from hand sanitizer bottle and another PDR strain from respirator. All PDR-A. baumannii (n 5 9) harbored blaOXA-69 gene and none carried mcr. Moreover, seven carried blaGES and blaOXA-23 genes. PFGE identified four pulsotypes (A, B, C, and D) with the pulsotype A gathering seven PDR-A. baumannii isolates: six from three patients and one from hygiene sample. MLST revealed that all PDR-A. baumannii isolates of pulsotype A belonged to the pandemic clone ST2. Systematic screening of MDR and PDR-A. baumannii is highly recommended to limit dissemination of such strains in ICUs. [ABSTRACT FROM AUTHOR]

Methanol is a renewable, low-carbon chemical that can be obtained from biomass. GeO2 is the main source for producing Ge, which is an important semiconductor. The current study aimed to investigate the reduction of GeO2 and chemical vapor deposition of Ge using gaseous species generated by methanol pyrolysis. Mass measurement, X-ray diffraction and scanning electron microscopy techniques were used to determine the extent of the oxide reduction, and to characterize the products. CO and H2 were predicted as the major reducing agents derived from the methanol pyrolysis at 1000 K to 1200 K, in agreement with the experimental measurement. It was found that the mass loss in GeO2 increased to 85.5 pct as the reaction time and temperature were raised to 10 minutes and to 1200 K. The GeO2 reduction was insignificant at 900 K, in contrast to the thermodynamic prediction, essentially owing to the sluggish reaction kinetics. At 1000 K, the significant reduction of GeO2 to Ge, close to the thermodynamic equilibrium, was attained. At 1100 K to 1200 K, the experimental mass loss was more than the thermodynamics prediction. The discrepancy was explained by a mass-transport theory involving boundary layer in the gas phase over the powder bed. Ge films were deposited from the gaseous species generated upstream at 1200 K for 10 minutes on a Si (400) substrate held downstream in the reaction tube at 723 K to 923 K. Polycrystalline rough Ge thin films with pillar-like crystals were obtained when the substrate temperatures were 723 K and 823 K. At 923 K, a denser polycrystalline Ge film was grown probably owing to the enhanced Ge diffusion on the substrate surface. [ABSTRACT FROM AUTHOR]

Using the [3+2] cycloaddition reaction of [HC≡C−GePh2−]2 (1) and a number of RCH2N3, this work described the synthesis of a series of novel heterocyclic digermanes, bitriazoles [1,4‐C2HN3(CH2R)GePh2−]2, 2–12 (R=Ph, p‐Tol, p‐C6H4NMe2, p‐C6H4OMe, p‐C6H4Br, m‐C6H4NO2, 2‐Naphth, CH2‐p‐OC6H4CHO, CH2‐p‐OC6H4COOMe, CH2P(O)(OEt)2, COOEt), difficult to produce by other methods. The structural peculiarities of these compounds were studied in detail by NMR spectroscopy and by XRD analysis (for 6, 9 and 10). The properties of 1–12 were studied by UV/vis and luminescence emission spectroscopy, electrochemistry and DFT calculations, indicating an effective conjugation in their molecules. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Hydrogermylation of alkenes and alkynes provides a straightforward synthetic route to organogermanium compounds that have been found applications in organic synthesis, medicinal chemistry, and material science. This paper reviews the advances in transition‐metal‐catalyzed hydrogermylation of unsaturated carbon‐carbon bonds, including alkenes, alkynes, dienes, and allenes, with the objective of providing readers with the status of the field. Progress, problems, and perspectives in this field are discussed. [ABSTRACT FROM AUTHOR]

(1) Background: Pseudomonas aeruginosa is a Gram-negative bacterium with several intrinsic and acquired antimicrobial resistance mechanisms. The spread of carbapenemase-encoding genes, an acquired mechanism, enables carbapenem resistance in clinical settings. Detection of the carbapenemase-producer strains is urgent. Therefore, we aimed to characterize carbapenemase production in the clinical strains of P. aeruginosa at a tertiary-care center. (2) Methods: We included clinical strains of P. aeruginosa (from August 2011 to December 2018) with resistance towards at least one carbapenem. Strains were isolated in a tertiary-care center in Mexico City. Antimicrobial susceptibility profiles were determined by broth microdilution. Screening for carbapenemase-encoding genes was performed in all strains. Phenotypic assays (CarbaNP and mCIM) were conducted. Additional modifications to mCIM were also tested. (3) Results: One-hundred seventy-one P. aeruginosa strains out of 192 included in this study were resistant towards at least one of the carbapenems tested. Forty-seven of these strains harbored a carbapenemase-encoding gene. VIM (59.6%) and GES (23.4%) were the most frequently found carbapenemases in our study, followed by IMP (14.9%). (4) Among the most frequent carbapenemase genes identified, metallo-ß-lactamases were the most prevalent, which impair new treatment options. Searching for carbapenemase genes should be performed in resistant isolates to stop transmission and guide antimicrobial treatment. [ABSTRACT FROM AUTHOR]

This review discusses sugar isomerization with organogermanium compounds. Organogermanium compounds markedly increase the aldose-ketose (glucose-fructose or lactose-lactulose) isomerization ratio, double the initial reaction rate, and significantly reduce the base-catalyzed degradation of sugars. ¹H-nuclear magnetic resonance analysis reveals that the affinity of organogermanium compounds with a 3-(trihydroxygermyl)propanoic acid (THGP) structure toward ketoses is 20-40 times stronger than that toward aldoses; thus, such organogermanium compounds form complexes more readily with ketoses than with aldoses. Stable ketose complexes, which contain multiple cis-diol structures and high fractions of furanose structures, suppress the reverse ketose-aldose reaction, thereby shifting the equilibrium toward the ketose side. These complexes also protect sugar molecules from alkaline degradation owing to the repulsion between anionic charges. The increased rate of the initial reaction in the alkaline isomerization process results from stabilizing the transition state by forming a complex between THGP and a cis-enediol intermediate. The cyclic pentacoordinate or hexacoordinate THGP structures give rise to a conjugated system of germanium orbitals, which is extended through dπ-pπ interactions, thereby improving the stability of the complex. Based on these results, we have developed a bench-scale lactulose syrup manufacturing plant incorporating a system to separate, recover, and reuse organogermanium poly-trans-[(2-carboxyethyl) germasesquioxane]. This manufacturing plant can be used as a model of an alkaline isomerization accelerator for continuous industrial production. [ABSTRACT FROM AUTHOR]

The aim of this work was to understand the main structural features and ways of formation of Ge-O bonds in organogermanium compounds under the conditions of ArnGeHal4-n (Hal = halide) hydrolysis. The structural types of these compounds were considered, providing 11 blocks (A–K). The molecular structures of the novel compounds [(p-FC6H4)3Ge]2O (1), [(p-F3CC6H4)3Ge]2O (2), and cyclo-[(p-F3CC6H4)2GeO]4 (3) were studied through XRD (X-ray diffraction) analysis. The molecular structure of [(p-F3CC6H4)3GeO]4Ge (4), representing a novel structural type, was also investigated. The data presented in this study will be important in the design of materials with useful properties based on group 14 element derivatives with element–oxygen bonding. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

[NHC → GeN(Ar)Cu2NAr]2, the formal adduct of germanium analogue of organic isonitrile [GeNAr] with Cu(I) imide [(Cu2NAr)2] (Ar = 2,6-iPr2C6H3) was prepared from the N-heterocyclic carbene (NHC) stabilized acyclic germylene Ge[N(H)Ar]2 by reacting with two equivalents of nBuLi and CuCl(PPh3)3. As elucidated by X-ray crystal structural characterization, the two separated [GeNAr] moieties interacted with [(Cu2NAr)2] core in the side-on mode. [ABSTRACT FROM AUTHOR]

α-L-Rhamnosidase (α-L-rhamnoside-rhamnohydrolase EC 3.2.1.40) showing specificity for terminal α-1,2-, α-1,4- and α-1,6-linked rhamnose residues, which oft en present in glycoconjugates and synthetic glycosides, can be successfully used in biotechnology for the hydrolysis of rhamnopyranoside residues present in some bioflavonoids, glycoproteins, glycolipids, and other glycoconjugates. Previously, we have shown that a significant part of the coordination compounds of various metals act as effectors of the activity of α-L-rhamnosidases. The aim of this investigation was to study the effect of a number of newly synthesized coordination compounds of Ge(IV) and Ba(II), (Co(II), Ni(II), Cu(II), Zn(II) with gluconic acid on the activity of Penicillium tardum and Eupenicillium erubescens α-L-rhamnosidases. Methods. The objects of the study were Penicillium tardum and Eupenicillium erubescens α-L-rhamnosidases. α-L-Rhamnosidase activity was determined by the Davis method using naringin as a substrate. Coordination compounds Ge(IV) and Ba(II), Co(II), Ni(II), Cu(II),and Zn(II) with gluconic acid were used as enzyme activity modifiers. The synthesized complexes correspond to the formulas [M(H2O)6][Ge2(OH)2(C6H8O7)2]⋅nH2O (M = Ba(1), n = 2; Co 2, n = 4; Ni(3), n = 4; Cu(4), n = 4; Zn(5), n = 3). Results. The effect of coordination compounds 1-(5) on the activity of α-L-rhamnosidase in two strains of Penicillium tardum and Eupenicillium erubescens was studied depending on the exposure time and concentration of the effector. It was shown that compound (3) at a concentration of 0.01% (1 h incubation) led to a slight (by 5%) increase in the activity of P. tardum α-L-rhamnosidase. Compound 1 at a concentration of 0.1% led to a decrease in the activity of P. tardum α-L-rhamnosidase by 29% during the first hour, and after 24 h of incubation, a decrease in the inhibitory effect to 15% was noted. Compounds 2 and (4) activated the enzyme by 9-39% at 1h exposure. At a concentration of 0.1% and exposure time of 1 h, compound 1 increased the activity of E. erubescens α-L-rhamnosidase by 80%, while at a decrease in concentration to 0.01%, the activity increased only by 29%. In general, it should be noted that in most cases, an increase in the duration of incubation up to 24 h led to a decrease in the level of activation (or inhibition) and a return to the control values of enzyme activity. Conclusions. The variety of effects of metal coordination compounds on the activity of enzymes, depending on the nature of the cation and the origin of the enzyme, has been established. The involvement of Ba(II) had the greatest activating effect on the activity of E. erubescens α-L-rhamnosidase compared to other metals. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Readily available, sterically, and electronically tunable sulfonamides have been developed as effective photoinduced hydrogen atom transfer (HAT) catalysts for selective Si−H functionalizations of a broad range of silanes. N‐centered radicals, catalytically generated from sulfonamides by photoredox catalyzed single‐electron oxidation, are the key intermediates that enable an effective HAT process for silyl radical generation to achieve hydrosilylation of activated alkenes. Additionally, this catalytic system can also be applied for the activation of Ge−H bond for hydrogermylation of activated alkenes through hydrogen atom transfer by sulfonamide derived nitrogen centered radical. The ability to generate silyl and germyl radical using this photochemical HAT process offers new avenue towards the sustainable synthesis of organosilicon and organogermanium compounds. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) sensors have a broad range of applications including healthcare, process control, and air quality analysis. There are a variety of techniques for detecting VOCs such as optical, acoustic, electrochemical, and chemiresistive sensors. However, existing commercial VOC detectors have drawbacks such as high cost, large size, or lack of selectivity. Herein, a new sensing mechanism is demonstrated based on surface interactions between VOC and UV‐excited 2D germanium sulfide (GeS), which provides an effective solution to distinguish VOCs. The GeS sensor shows a unique time‐resolved electrical response to different VOC species, facilitating identification and qualitative measurement of VOCs. Moreover, machine learning is utilized to distinguish VOC species from their dynamic response via visualization with high accuracy. The proposed approach demonstrates the potential of 2D GeS as a promising candidate for selective miniature VOCs sensors in critical applications such as non‐invasive diagnosis of diseases and health monitoring. [ABSTRACT FROM AUTHOR]

This article demonstrates simple germanium-doped solid-core photonic quasi-crystal fiber (PQF) for biochemical sensing applications. The chemically stable thin gold film and eightfold rhombic triacontahedron photonic quasi-crystal structure subsumed in the improved external sensing approach using the finite element method (FEM) tool. The optimized rhombic PQF structure was numerically developed using 14,862 finite mesh elements. The FEM analysis shows high wavelength and amplitude sensitivity, low confinement loss, good figure of merit, high detection accuracy, and reasonable resolution at the refractive index (RI) values from 1.32 to 1.36. Based on the results, this unique rhombic PQF structure has advantages in the high sensitivity with low loss and ease of fabrication among the existing PQF and photonic crystal fiber sensors in biochemical sensing applications. [ABSTRACT FROM AUTHOR]

In this review, the latest achievements in the field of multiply bonded organogermanium derivatives, mostly reported within the last two decades, are presented. The isolable Ge-containing analogues of alkenes, alkynes, 1,3-dienes, allenes, and vinylidenes are discussed, and for each class of unsaturated organogermanium compounds, the most representative examples are given. The synthetic approaches toward homonuclear multiply bonded combinations solely consisting of germanium atoms, and their heteronuclear variants containing germanium and other group 14 elements, both acyclic and cyclic, are discussed. The peculiar structural features and nonclassical bonding nature of the abovementioned compounds are discussed based on their spectroscopic and structural characteristics, in particular their crystallographic parameters (double bond length, trans-bending at the doubly bonded centers, and twisting about the double bond). The prospects for the practical use of the title compounds in synthetic and catalytic fields are also briefly discussed. [ABSTRACT FROM AUTHOR]

Eleven new extremely bulky aryl/silyl substituted secondary amines, L1–11H, have been prepared. These incorporate a combination of one of the bulky aryl groups, C6H2{C(H)Ph2}2R‐2,6,4; R=Me (Ar*), Pri (Ar†); C6H2{C(H)(C6H3But2‐3,5)2}2Me‐2,6,4) (Ar#); or C6H2{C(H)(2‐naphthyl)2}2Me‐2,6,4 (Ar¥), and one of the silyl fragments, SiMe3, SiCy3 (Cy=cyclohexyl), SiPri3, Si(p‐C6H4But)3, or Si(OBor)3 (OBor=[(1S)‐endo]‐(−)‐borneoxy). Amines including the latter silyl group represent the first enantiopure examples of this ligand class. All amines are readily deprotonated with n‐butyllithium or KH. Reactions of five alkali metal amide complexes with GeCl2⋅dioxane have given monomeric amido‐germanium(II) chloride complexes, LxGeCl (x=1–4, 7). Treatment of two of these with KOBut afforded monomeric amido‐germanium(II) tert‐butoxide species, LxGeOBut (x=1 or 3). Reductions of two amido‐germanium(II) chloride systems with a dimagnesium(I) compound afforded amido‐digermyne species, LxGeGeLx (x=3 or 4), the X‐ray crystal structures of which show them to possess very short Ge−Ge bonds, with considerable implied multiple bond character. [ABSTRACT FROM AUTHOR]

M1 macrophages are an important cell type related to tumor immunology and are known to phagocytose cancer cells. In previous studies, the organogermanium compound poly-trans-[(2-carboxyethyl)germasesquioxane] (Ge-132) and its hydrolysate, 3-(trihydroxygermyl) propanoic acid (THGP), have been reported to exert antitumor effects by activating NK cells and macrophages through the induction of IFN-γ activity in vivo. However, the detailed molecular mechanism has not been clarified. In this study, we found that macrophages differentiate into the M1 phenotype via NF-κB activation under long-term culture in the presence of THGP in vitro and in vivo. Furthermore, long-term culture with THGP increases the ability of RAW 264.7 cells to suppress B16 4A5 melanoma cell proliferation. These mechanisms indicate that THGP promotes the M1 polarization of macrophages and suppresses the expression of signal-regulatory protein alpha (SIRP-α) in macrophages and CD47 in cancers. Based on these results, THGP may be considered a new regulatory reagent that suppresses tumor immunity. [ABSTRACT FROM AUTHOR]

In this paper, we studied some ferroelectric properties of archetypal oxide uniaxial ferroelectric single crystals of Pb5Ge3O11 modified by Ba ions. They include dielectric, DSC, ferroelectric polarization, and electrocaloric effect (ECE) measurements. The measurements show that increasing Ba doping considerably influences all the measured parameters, mainly by lowering the Curie temperature, gradually diffusing the phase transition, and decreasing values of polarization as well as the coercive field. The decrease in overall ECE is influenced by decreasing polarization. Compared with the pure PGO single crystals, this decrease is from 1.2 K to 0.2 K. However, the effect of diffusing the phase transition increases the range of its occurrence (up to 30 K), which might be beneficial in applications. [ABSTRACT FROM AUTHOR]

Germanium–polyamide 6 (Ge-PA6) fibers A, B and C containing germanium particles with sizes of D50 = 0.2, 2 and 7 μm were prepared using the melt spinning method. The effect of germanium particle size on the morphologies, mechanical properties, negative air ion (NAI) release and antimicrobial efficiencies of the two kinds of fibers were compared and analyzed. The NAI release and antimicrobial mechanisms of the Ge-PA6 fibers were also discussed. Results indicated that the germanium particles dispersed well inside the PA6 fiber substrate in the range of 1–3 wt%, and smaller particles help the fiber to obtain better diameter evenness and mechanical performance compared with larger ones. The stronger extranuclear electron activity and electrostatic voltage along the C -axis allow the fiber that contains smaller germanium particles to produce more NAIs compared to that containing larger particles. Some 780 and 1587 ions/m3 of NAIs could be produced by fiber A under the circumstance of 35°C and 40 N extrusion force when the germanium concentration was fixed at 3 wt%. The excellent NAI release property of the Ge-PA6 fiber endows it with inspiring antibacterial activity against S. aureus and C. albicans with a 12 h bacteriostasis rate of more than 90% at human body temperature. These results indicated Ge-PA6 fibers have great application potential in apparel and medical textiles. [ABSTRACT FROM AUTHOR]

Inflammasome activity is a key indicator of inflammation. The inflammasome is activated by pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), which activate the p38-NF-κB pathway and promote IL-1β transcription (signaling step 1). Next, extracellular adenosine triphosphate (ATP) activates the inflammasome (a protein complex consisting of a signal recognition protein, an adapter protein, and Caspase-1) and secretion of inflammatory cytokines such as IL-1β (signaling step 2). Inflammasome activation causes excessive inflammation, leading to inflammasome-active diseases such as atherosclerosis and type 2 diabetes. A hydrolysate of the organogermanium compound Ge-132, 3-(Trihydroxygermyl) propanoic acid (THGP) can form a complex with a cis-diol structure. We investigated the inhibitory effect of THGP on inflammasome activity in human THP-1 monocytes. THGP inhibited IL-1β secretion and caspase-1 activation (signaling step 2) in an ATP-dependent manner. On the other hand, THGP did not suppress IL-1β secretion induced by only lipopolysaccharide (LPS) stimulation. In addition, as IL-6 is an ATP-independent inflammatory cytokine, THGP did not decrease its secretion. THGP also suppressed pyroptosis, which is a caspase-1 activity-dependent form of cell death. Therefore, THGP is expected to become a new therapeutic or prophylactic agent for inflammasome-associated diseases. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A dual-photofunctional organogermanium compound based on a donor–acceptor–donor architecture that exhibits thermally activated delayed fluorescence and mechano-responsive luminochromism has been developed. The developed compound was successfully applied as an emitter for efficient organic light-emitting diodes. [ABSTRACT FROM AUTHOR]

Derivatives of main group elements containing element–element bonds are characterized by unique properties due to σ-conjugation, which is an attractive subject for investigation. A novel series of digermanes, Ar3Ge-Ge(SiMe3)3, containing aryl (Ar = p-C6H4Me (1), p-C6H4F (2), C6F5 (3)) and trimethylsilyl substituents, was synthesized by the reaction of germyl potassium salt, [(Me3Si)3GeK*THF], with triarylchlorogermanes, Ar3GeCl. The optical and electronic properties of such substituted oligoorganogermanes were investigated spectroscopically by UV/vis absorption spectroscopy and theoretically by DFT calculations. The molecular structures of compounds 1 and 2 were studied by XRD analysis. Conjugation between all structural fragments (Ge-Ge, Ge-Si, Ge-Ar, where Ar is an electron-donating or withdrawing group) was found to affect the properties. [ABSTRACT FROM AUTHOR]

The study of intermolecular interactions is of great importance. This study attempted to quantitatively examine the interactions between acrolein (C3H4O) and fullerene nanocages, C60, in vacuum. As the frequent introduction of elements as impurities into the structure of nanomaterials can increase the intensity of intermolecular interactions, nanocages doped with silicon and germanium have also been studied as adsorbents, C59Si and C59Ge. Quantum mechanical studies of such systems are possible in the density functional theory (DFT) framework. The main part of this work is the study of various analyses that reveal the nature of the intermolecular interactions between the two components introduced above. The results of conceptual DFT, natural bond orbital, non-covalent interactions, and quantum theory of atoms in molecules were consistent and in favor of physical adsorption in all systems. Germanium had more adsorption energy than other dopants. The HOMO–LUMO energy gaps were as follows: C60: 5.996, C59Si: 5.309, and C59Ge: 5.188 eV at B3LYP-D3/6-311G (d) model chemistry. The sensitivity of the adsorption increased when a gas molecule interacted with doped C60, and this capability could be used to design nanosensors to detect acrolein gas. [ABSTRACT FROM AUTHOR]

We studied the solid-phase reaction between a thin Ni film and a single crystal Ge(001) or Ge(111) substrate during a ramp anneal. The phase formation sequence was determined using in situ X-ray diffraction and in situ Rutherford backscattering spectrometry (RBS), while the nature and the texture of the phases were studied using X-ray pole figures and transmission electron microscopy. The phase sequence is characterized by the formation of a single transient phase before NiGe forms as the final and stable phase. X-ray pole figures were used to unambiguously identify the transient phase as the ϵ-phase, a non-stoichiometric Ni-rich germanide with a hexagonal crystal structure that can exist for Ge concentrations between 34% and 48% and which forms with a different epitaxial texture on both substrate orientations. The complementary information gained from both RBS and X-ray pole figure measurements revealed a simultaneous growth of both the ϵ-phase and NiGe over a small temperature window on both substrate orientations. [ABSTRACT FROM AUTHOR]

We previously demonstrated that the organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) enhances the enzymatic and alkaline isomerization of an aldose to a ketose through cis-diol complex formation by multiple mechanisms. Its higher affinity for the ketose than the aldose protects the ketose complex from alkaline decomposition. Furthermore, it has been reported that the aldoseketose alkaline isomerization pathway includes 1,2-enediol. Therefore, we speculated that the complexforming ability of THGP could also be applied to enediol, a transient intermediate of alkaline isomerization. To test this prediction, we analyzed the initial rates of glucose or lactose isomerization in a region where there was no substantial difference in pH with and without THGP addition. The results showed that THGP enhanced the rate of fructose or lactulose formation per unit time by approximately 2-fold compared to the control. This finding indicated that THGP could form a complex with the transition state of aldoseketose alkaline isomerization. [ABSTRACT FROM AUTHOR]

Reactions of 1-(chloromethyl)silatrane with organic group 14 element anions [(Me3Si)3E]‒ (E = Si, Ge) generated in situ afforded the corresponding substitution products (Me3Si)3ECH2Si(OCH2CH2)3N, whereas no products of ring-expansion rearrangement were detected. The structure of the isolated compounds was determined by multinuclear NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Germylenes, organic compounds of divalent germanium, are often considered as promising catalytic systems efficient in reactions of oxidative addition and reductive elimination, including SET reactions. However, the systematic studies of their redox properties, allowing for the quantitative evaluation of the levels of frontier molecular orbitals and the stability of single electron transfer products, are extremely limited in number. In this work, a series of germylenes with various types of stabilization: N-Ge-N, (N→)C-Ge-C(←N), N-Ge-N(←N), O-Ge-O(←N) и (N→)O-Ge-O(←N) ("-" -a covalent bond, stabilization is achieved by p-donation of a lone pair of electrons of N or O, "→" -donor-acceptor bond) were characterized by cyclic voltammetry. The results were compared with UV/Vis spectroscopy data and DFT calculations. All germylenes studied in MeCN and THF with Bu4NPF6 as a supporting electrolyte are chemically irreversibly oxidized in the potential range of 0.5-1.4 V vs. Ag/AgCl. In all cases, as estimated by the quantum chemical calculations, the HOMO remains at the covalently unsaturated germanium center although being significantly redistributed over the molecular system. In turn, electroreduction of germylenes is possible only in the presence of a strong electron-withdrawing substituent or a pyridine ring depleted in electron density donated to germanium. In both cases, the LUMO is localized exactly on these moieties and is absent on the germanium. Thus, the use of stabilizing groups makes it possible both to improve germylene stability and to fine-tune their HOMO level that determines their ability to participate in oxidative addition reactions. [ABSTRACT FROM AUTHOR]

We highlight our recent researches on an alkylation-terminated Catellani reaction using alkylcarbagermatranes. This strategy highlights the unique structure and property of alkylcarbagermatranes and also fills the gap in the Catellani reaction where alkylation termination was missing. [ABSTRACT FROM AUTHOR]

3-tert-Butyl-8-methyl-4-triphenylgermyl-1,4-dihydropyrazolo[5,1-c][1,2,4]triazine and 2-(6-tert-butyl-5-triphenylgermyl-2-R-4,5-dihydro-1,2,4-triazin-3(2H)-ylidene)malononitriles (R = Me, Bun, CH2CO2But) were synthesized by the nucleophilic addition of triphenylgermyllithium to the corresponding aromatic 1,2,4-triazines at low temperature. New organogermanium derivatives of 1,2,4-triazines were characterized by IR, HRMS, 1H, 13C, and 73Ge NMR spectroscopy, as well as by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

In this study, 7-(4-ethyl-1-methyloctyl)-8-quinolinol (HL, Kelex 100) and 5,8-diethyl-7-hydroxydodecane-6-oxime (LIX 63, HA) were employed to recover Ge(IV) from sulfuric acid solutions in the presence of singly charged inorganic anions. Under comparable conditions, the germanium extraction efficiency was in the order Cl−3−3]+[CNS]− and Ge(OH)2A(CNS) respectively. An increase in the pH values was shown to lead to a decrease in the extraction of Ge(IV) with HL from sulfate-thiocyanate solutions. At pH values of ≥5.9, the degree of germanium recovery is <2.0 % which makes stripping with alkaline aqueous solutions possible. When adding bis(2,4,4-trimethylpentyl)acid (HR, CYANEX 301) to the HL and HA mixture, a significant synergistic effect takes place. The composition of the extracted complex with Kelex 100 was found to be [GeL3]+[R−]. The use of extraction systems based on both Kelex 100 and LIX 63, and on their mixture with CYANEX 301 in the presence of thiocyanate ion is of undoubted practical interest for hydrometallurgical processes to recover germanium. [ABSTRACT FROM AUTHOR]

Amide functional groups are an essential linkage that are found in peptides, proteins, and pharmaceuticals and new methods are constantly being sought for their formation. Here, a new method for their preparation is presented where germanium amides Ph3GeNR2 convert acid fluorides directly to amides. These germanium amides serve to abstract the fluorine atom of the acid fluoride and transfer their amide group –NR2 to the carbonyl carbon, and so function as amidation reagents. [ABSTRACT FROM AUTHOR]

Dinuclear low‐valent compounds of the heavy main group elements are rare species owing to their intrinsic reactivity. However, they represent desirable target molecules due to their unusual bonding situations as well as applications in bond activations and materials synthesis. The isolation of such compounds usually requires the use of substituents that provide sufficient stability and synthetic access. Herein, we report on the use of strongly donating ylide‐substituents to access low‐valent dinuclear group 14 compounds. The ylides not only impart steric and electronic stabilization, but also allow facile synthesis via transfer of an ylide from tetrylene precursors of type RY2E to ECl2 (E=Ge, Sn; RY=TolSO2(PR3)C with R=Ph, Cy). This method allowed the isolation of dinuclear complexes amongst a germanium analogue of a vinyl cation, [(PhY)2GeGe(PhY)]+ with an electronic structure best described as a germylene‐stabilized GeII cation and a ylide(chloro)digermene [CyY(Cl)GeGe(Cl)CyY] with an unusually unsymmetrical structure. [ABSTRACT FROM AUTHOR]

The Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho‐alkylation was one of the earliest applications of the Catellani reaction, ipso‐alkylation‐terminated reactions with β‐H‐containing reactants has not been realized to date. Herein, we report alkylation‐terminated Catellani reaction using alkyl carbagermatranes (abbreviated as alkyl‐Ge) as nucleophiles. The reactivity of alkyl‐Ge and alkyl‐B(OH)2 in this reaction is discussed. This approach enables efficient dialkylation with β‐H‐containing reactants, which was previously inaccessible by Catellani reactions. [ABSTRACT FROM AUTHOR]

The Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho‐alkylation was one of the earliest applications of the Catellani reaction, ipso‐alkylation‐terminated reactions with β‐H‐containing reactants has not been realized to date. Herein, we report alkylation‐terminated Catellani reaction using alkyl carbagermatranes (abbreviated as alkyl‐Ge) as nucleophiles. The reactivity of alkyl‐Ge and alkyl‐B(OH)2 in this reaction is discussed. This approach enables efficient dialkylation with β‐H‐containing reactants, which was previously inaccessible by Catellani reactions. [ABSTRACT FROM AUTHOR]

Germanium has long been considered a therapeutic agent with anticancer, antitumor, antiaging, antiviral and anti-inflammatory effects. Numerous clinical studies have explored the promising therapeutic effects of organic germanium on cancer, arthritis and senile osteoporosis. The immune activation property of organic germanium is considered the foundation of its various therapeutic effects. However, previous human clinical studies investigating immune activation with organic germanium compounds have certain limitations, as some studies did not strictly follow a randomized, double-blind, placebo-controlled design. To build a more clinically substantiated foundation for the mechanism underlying its immunostimulation, we structured by far the most rigorous clinical study to-date with a group of 130 human subjects to examine changes in immune profiles following germanium supplementation. We used Bio-Germanium, an organic germanium compound naturally synthesized via a yeast fermentation process. An 8-week randomized, double-blind, placebo-controlled study was conducted with 130 subjects with leukocyte counts of 4–8 (×103/μL) divided into the Bio-Germanium group and the placebo group. Anthropometric measurements; blood collection; biochemical analysis; urinalysis; and natural killer cell activity, cytokine and immunoglobulin assays were conducted. Results showed the Bio-Germanium group exhibited NK cell activity increases at effector cell:target cell (E:T) ratios of 50:1, 10:1, 5:1 and 2.5:1 (12.60±32.91%, 10.19±23.88%, 9.28±16.49% and 7.27±15.28%, respectively), but the placebo group showed decreases (P<0.01). The difference in the IgG1 change from baseline to follow-up between the Bio-Germanium and placebo groups was significant (P = 0.044). Our results and earlier clinical study of Bio-Germanium confirm that Bio-Germanium acts as an effective immunostimulant by increasing the cytotoxicity of NK cells and activating immunoglobulin, B cells and tumor necrosis factor (TNF)-α (P<0.05). As we have added newly discovered clinical findings for germanium's immunostimulation mechanism, we believe Bio-Germanium is a highly promising therapeutic agent and should certainly be further explored for potential development opportunities in immunotherapy. Registered clinical trial: [NCT03677921]; www.clinicaltrials.gov [KCT0002726]; https://cris.nih.go.kr [ABSTRACT FROM AUTHOR]

Abstract. With the attempt to synthesize Nb‐enclosed germanium Zintl cluster ion in ethylenediamine (en) / toluene solution, the reaction of K4Ge9/Na4Ge9 with Nb(mes)2 (mes = mesitylene) gives unexpected 18‐crown‐6 cleavage product of [K14Na2(NbO2)2(C8H16O5)8](Ge5) (en)·solv in the form of very air‐sensitive, light‐brown, plate‐like crystals. This unique compound crystallizes in monoclinic Pn (No. 7) space group, the cleavage of crown linked the 14 potassium, 2 sodium, and 2 niobium atoms into the bulky 2+ charged cation, which balances the [Ge5]2– anion. This compound represents the rare example of heteronuclear metal alkoxide / Zintl ion hybrid. [ABSTRACT FROM AUTHOR]