Influence of triphosphine ligand coordination geometry in Mn(I) hydride complexes [(PPP)(CO)MnH] on their kinetic hydricity.

Octahedral Mn(I) complexes bearing tridentate donor ligands [(LL'L'')(CO)MnX] have recently emerged as major players in catalytic (de)hydrogenation processes. While most of these systems are still based on structurally rigid pincer scaffolds imposing a meridional coordination mode, for some more flexible tridentate ligands a facial arrangement of donor moieties becomes possible. Accordingly, the geometry of the corresponding Mn(I) hydrides [(LL'L'')(CO)MnH] directly involved in the catalytic processes, namely the nature of the donor extremity located in the -position of the hydride (CO and L for - and -configurations, respectively) may influence their hydride transfer ability.

Synergism of primary and secondary interactions in a crystalline hydrogen peroxide complex with tin.

Despite the significance of HO-metal adducts in catalysis, materials science and biotechnology, the nature of the interactions between HO and metal cations remains elusive and debatable. This is primarily due to the extremely weak coordinating ability of HO, which poses challenges in characterizing and understanding the specific nature of these interactions. Herein, we present an approach to obtain HO-metal complexes that employs neat HO as both solvent and ligand.

Ethnicity and the Prevalence of Polycystic Ovary Syndrome: The Eastern Siberia PCOS Epidemiology and Phenotype Study.

Context: Previous studies have shown that the prevalence of polycystic ovary syndrome (PCOS) may vary according to race/ethnicity, although a few studies have assessed women of different ethnicities who live in similar geographic and socioeconomic conditions.

Objective: To determine the prevalence of PCOS in an unselected multiethnic population of premenopausal women.

Design: A multicenter prospective cross-sectional study.

Two active species from a single metal halide precursor: a case study of highly productive Mn-catalyzed dehydrogenation of amine-boranes intermolecular bimetallic cooperation.

Metal-metal cooperation for inert bond activation is a ubiquitous concept in coordination chemistry and catalysis. While the great majority of such transformations proceed intramolecular mode in binuclear complexes, to date only a few examples of intermolecular small molecule activation using usually bimetallic frustrated Lewis pairs (M⋯M') have been reported. We introduce herein an alternative approach for the intermolecular bimetallic cooperativity observed in the catalytic dehydrogenation of amine-boranes, in which the concomitant activation of N-H and B-H bonds of the substrate the synergetic action of Lewis acidic (M) and basic hydride (M-H) metal species derived from the same mononuclear complex (M-Br).

Polycystic Ovary Syndrome and Gut Microbiota: Phenotype Matters.

Abnormalities in gut microbiota diversity are considered important mechanisms in metabolic disorders in polycystic ovarian syndrome (PCOS). However, the data on the association of these disorders with the PCOS phenotype remain controversial. The objectives of this study were to estimate the alpha diversity of the gut microbiota of healthy women and PCOS patients depending on phenotype.

Establishing Normative Values to Determine the Prevalence of Biochemical Hyperandrogenism in Premenopausal Women of Different Ethnicities from Eastern Siberia.

Androgen assessment is a key element for diagnosing polycystic ovary syndrome (PCOS), and defining a "normal" level of circulating androgens is critical for epidemiological studies. We determined the upper normal limits (UNLs) for androgens in a population-based group of premenopausal "healthy control" women, overall and by ethnicity (Caucasian and Asian), in the cross-sectional Eastern Siberia PCOS Epidemiology and Phenotype (ESPEP) Study (ClinicalTrials.gov ID: NCT05194384) conducted in 2016-2019.

Versatile Reactivity of Half-Sandwich Rhodium(III) Iminophosphonamide Complexes.

Novel 18e̅ and 16e̅ pentamethylcyclopentadienyl rhodium(III) complexes [(η-CMe)RhX(NPN)] (, X = Cl; , X = PF, BAr) with chelating zwitterionic iminophosphonamide (NPN) ligands (PhP(NR)(NR'); , R = R' = -Tol; , R = -Tol, R' = Me; , R = R' = Me) were synthesized and characterized by single-crystal X-ray diffraction. In the 16e̅ complexes , the rhodium (Rh) atom is efficiently stabilized by π-donation of unshared N electrons, thus hampering coordination of the external ligands and rendering the 18e̅ complexes labile. Due to low coordination enthalpy, the cationic 18e̅ monocarbonyl and pyridine adducts are stable only at low temperatures.

-to- isomerization triggers hydride transfer from Mn(I) complex -[(dppm)Mn(CO)H].

Low-temperature IR and NMR studies combined with DFT calculations revealed the mechanistic complexity of apparently simple reactions between Mn(I) complex -[(dppm)Mn(CO)H] and Lewis acids (LA = PhC, B(CF)) involving the formation of so-far elusive meridional hydride species -[(dppm)Mn(CO)H⋯LA] and unusual dearomatization of the PhC cation upon hydride transfer.

Cyclometalated (NNC)Ru(II) complex catalyzed β-methylation of alcohols using methanol.

Indolyl fragment containing phenanthroline based new ligands and their corresponding Ru(II) complexes were synthesized and fully characterized by various spectroscopic techniques. The catalytic activity of these newly synthesized cyclometalated (NNC)Ru(II) complexes was explored towards the β-methylation of alcohols using methanol. Notably, these complexes displayed superior reactivity compared to various (NNN)Ru(II) complexes.

Amine-boranes reactions promoted by lanthanide(II) ions.

The catalytic activity in amine-borane dehydrogenation is shown for the first time for Ln(II) species using complexes [{(Bu-CH)CH}M·L] (M = Yb, Sm, L = (DME), TMEDA). The protonation of M(II)-C bonds with HNRRBH affords amidoborane complexes [M(NRRBH)L], which under excess HNMeBH transform to [NMeBHNMeBH] derivatives, both serving as the dehydrocoupling intermediates.

The Reaction of Hydrogen Halides with Tetrahydroborate Anion and Hexahydro--hexaborate Dianion.

The mechanism of the consecutive halogenation of the tetrahydroborate anion [BH] by hydrogen halides (HX, X = F, Cl, Br) and hexahydro--hexaborate dianion [BH] by HCl via electrophile-induced nucleophilic substitution (EINS) was established by ab initio DFT calculations [M06/6-311++G(d,p) and wB97XD/6-311++G(d,p)] in acetonitrile (MeCN), taking into account non-specific solvent effects (SMD model). Successive substitution of H by X resulted in increased electron deficiency of borohydrides and changes in the character of boron atoms from nucleophilic to highly electrophilic. This, in turn, increased the tendency of the B-H bond to transfer a proton rather than a hydride ion.

Bifunctional activation of amine-boranes by the W/Pd bimetallic analogs of "frustrated Lewis pairs".

The reaction between basic [(PCP)Pd(H)] (PCP = 2,6-(CHP(-CH))CH) and acidic [LWH(CO)] (L = Cp (), Tp (); Cp = η-cyclopentadienyl, Tp = κ-hydridotris(pyrazolyl)borate) leads to the formation of bimolecular complexes [LW(CO)(μ-CO)⋯Pd(PCP)] (, ), which catalyze amine-borane (MeNHBH, BuNHBH) dehydrogenation. The combination of variable-temperature (H, P{H}, B NMR and IR) spectroscopies and computational (ωB97XD/def2-TZVP) studies reveal the formation of an η-borane complex [(PCP)Pd(MeNHBH)][LW(CO)] () in the first step, where a BH bond strongly binds palladium and an amine group is hydrogen-bonded to tungsten. The subsequent intracomplex proton transfer is the rate-determining step, followed by an almost barrierless hydride transfer.

Cellular Immune Response of an Endemic Lake Baikal Amphipod to Indigenous Pseudomonas sp.

Studies of invertebrates have shown that the internal environment of crustaceans is not always sterile in normal conditions, and in many species, it can be populated by microorganisms even in the absence of any visible pathological processes in the body. This observation raises the question of whether genetically modified indigenous hemolymph microorganisms can be used for biotechnological purposes inside the crustacean either as local producers of some compounds or as sensors to physiological parameters. In this study, we tested the ability of the bacteria isolated from the hemolymph of the amphipod Eulimnogammarus verrucosus to hide from the cellular immune response of the host as the most important feature for their potential long-term application in vivo.

Metagenomic 16S rDNA amplicon datasets from adolescents with normal weight, obesity, and obesity with irritable bowel syndrome from Eastern Siberia, Russia.

Childhood obesity and its consequences are a significant public health problem worldwide. Gut microbiota has a potential role in the development of. In the current datasets, we present 16S rDNA amplicon metasequencing of the gut microbiome of adolescents with normal weight, obesity, and obesity with irritable bowel syndrome (IBS) carried out using the Illumine platform.

Metagenome datasets from women with polycystic ovary syndrome from Irkutsk, Eastern Siberia, Russia.

For the metagenomic characterization of potential taxonomic and functional diversity of microorganisms associated with polycystic ovary syndrome (PCOS) in women, we surveyed five women with PCOS and collected samples of feces, saliva, and serum. After quality processing, we have obtained from 915,594 to 3,880,379 reads; these 16,693 sequences had ribosomal RNA genes, 2,091,990 sequences contained predicted proteins with known functions, and 3,750,261 sequences had predicted proteins with unknown functions. Host DNA accounted for ca.

Stereoisomerism as an Origin of Different Reactivities of Ir(III) PC(sp)P Pincer Catalysts.

Two stereoisomers of pentacoordinate iridium(III) hydridochloride with triptycene-based PC(sp)P pincer ligand (1,8-bis(diisopropylphosphino)triptycene), and , differ by the orientation of hydride ligand relative to the bridgehead ring of triptycene. According to DFT/B3PW91/def2-TZVP calculations performed, an equatorial Cl ligand can relatively easily change its position in , whereas that is not the case in . Both complexes and readily bind the sixth ligand to protect the empty coordination site.

Dichotomous Si-H Bond Activation by Alkoxide and Alcohol in Base-Catalyzed Dehydrocoupling of Silanes.

The activation of silanes in dehydrogenative coupling with alcohols under general base catalysis was studied experimentally (using multinuclear NMR, IR, and UV-visible spectroscopies) and computationally (at DFT M06/6-311++G(d,p) theory level) on the example of PhSiH ( = 1-3) interaction with (CF)CHOH in the presence of EtN. The effect of the phenyl groups' number and H substitution by the electron-withdrawing (CF)CHO group on Si-H bond hydricity (quantified as hydride-donating ability, HDA) and Lewis acidity of silicon atom (characterized by maxima of molecular electrostatic potential) was accessed. Our results show the coordination of Lewis base (Y = MeN, ROH, OR) leads to the increased hydricity of pentacoordinate hypervalent PhSi(Y)H complexes and a decrease of the reaction barrier for H release.

Thermodynamic Hydricity of Small Borane Clusters and Polyhedral -Boranes.

Thermodynamic hydricity (HDA) determined as Gibbs free energy (ΔG°[H]) of the H detachment reaction in acetonitrile (MeCN) was assessed for 144 small borane clusters (up to 5 boron atoms), polyhedral -boranes dianions [BH], and their lithium salts Li[BH] (n = 5-17) by DFT method [M06/6-311++G(d,p)] taking into account non-specific solvent effect (SMD model). Thermodynamic hydricity values of diborane BH (HDA = 82.1 kcal/mol) and its dianion [BH] (HDA = 40.

Steric and Electronic Effect of Cp-Substituents on the Structure of the Ruthenocene Based Pincer Palladium Borohydrides.

Ruthenocene-based PCP pincer ligands were used to synthesize novel pincer palladium chloride Rc[PCP]PdCl () and two novel palladium tetrahydroborates Rc[PCP]Pd(BH) () and Rc[PCP]Pd(BH) (), where Rc[PCP] = κ-{2,5-(tBuPCH)CH}Ru(Cp) (Cp = CMeCF), and Rc*[PCP] = κ-{2,5-(tBuPCH)CH}Ru(Cp*) (Cp* = CMe). These coordination compounds were characterized by X-ray, NMR and FTIR techniques. Analysis of the X-ray data shows that an increase of the steric bulk of non-metalated cyclopentadienyl ring in and relative to non-substituted Rc[PCP]Pd(BH) analogue (; where Rc[PCP] = κ-{2,5-(tBuPCH)CH}Ru(Cp), Cp = CH) pushes palladium atom from the middle plane of the metalated Cp ring in the direction opposite to the ruthenium atom.

Mechanistic diversity in acetophenone transfer hydrogenation catalyzed by ruthenium iminophosphonamide complexes.

A series of arene ruthenium iminophosphonamide complexes, [(Arene)RuCl{RP(NR')}] (1), bearing various arenes and R,R' substituents on the NPN ligand have been investigated as precatalysts in acetophenone transfer hydrogenation in basic and base-free isopropanol. The results clearly demonstrate the presence of two distinct reaction mechanisms, which are controlled by the basicity of the N-atoms. Complexes 1 in which both R' substituents are aryl groups are only active once the neutral hydride complex [(Arene)RuH{RP(NR')}] (2) is generated in basic isopropanol, the latter being able to reduce a ketone via a stepwise hydride and proton transfer.

Metagenomic analysis of mycobacterial transrenal DNA in patients with HIV and tuberculosis coinfection.

The existence of "transrenal" DNA (tr-DNA), i.e. cell-free DNA that has distributed through the renal barrier to the urine, was first shown from a pathogen in 2000 (Botezatu et al.

Synthesis, structural properties and reactivity of ruthenocene-based pincer Pd(ii) tetrahydroborate.

Two novel ruthenocene-based pincer palladium tetrahydroborates were characterized by XRD, NMR and FTIR. The alcoholysis of Pd(ii) tetrahydroborate LPd(BH) (L = κ-[{2,5-(BuPCH)CH}Ru(CH)]) yields the dinuclear cationic Pd(ii) tetrahydroborate with the bridging BH ligand [(LPd)(μ,η:η-BH)]. The bifurcate dihydrogen-bonded complexes are the active intermediates of the first proton transfer in the step-wise alcoholysis of LPd(BH), yielding eventually [(LPd)(μ,η:η-BH)].

The Phylogenetic Position of Spironucleus sp. (Diplomonadida: Hexamitidae) from the Intestine of Chinese Sleeper Perccottus glenii Dybowski, 1877 (Actinopterygii: Odontobutidae).

Introduction: The Chinese (Amur) sleeper (Perccottus glenii Dybowski, 1877) (Actinopterygii: Odontobutidae) is a freshwater fish species with high invasive potential. Diplomonads have been detected in the intestines of Chinese sleepers using light microscopy.

Aim: The aim of this study was to identify the diplomonads in Chinese sleepers using molecular-genetic methods.

Diversity and shifts of the bacterial community associated with Baikal sponge mass mortalities.

The disease of freshwater sponges was first discovered in 2011, when pink samples were found in the Central Basin of Lake Baikal. Subsequently, the visible signs of the disease have changed, and now sponges appear with various symptoms of damage to the body, such as discoloration, tissue necrosis, the formation of brown patches and dirty-purple biofilms on some branches. These signs of the disease are accompanied by the mass death of sponges.