Two new binuclear copper(I) complexes [Cu2X2L2] (X = Br, I) based on chiral nopinane-annelated spirodiazafluorene L have been synthesized and characterized. X-ray diffraction analysis reveals that the complexes consist of flat rhomboid {Cu2X2} fragments whose copper atoms are chelated by the N,N '-donor ligand L. Strong deviation from the tetrahedral geometry around the Cu atoms is observed in the complexes due to the presence of intermolecular pi-pi stacking interactions and the steric effects of the bulky ligand L. DFT studies were performed to explore geometries, electronic structures, and absorption properties of the complexes in CH2Cl2 solution. The [Cu2X2L2] complexes exhibit bright photoluminescence with short decay lifetimes (< 2.5 mu s) and an emission color that depends on the nature of the mu(2)-halide atom.

ABSTRACT A series of 1‐aryl‐5‐aminopyrazoles was synthesized from 3‐iminobutanenitrile and substituted arylhydrazines under microwave irradiation (115°C–120°C) in ethanol, affording the target compounds in moderate to excellent isolated yields (28%–89%). Subsequently, the synthesized 1‐aryl‐5‐aminopyrazoles were reacted with myrtenal under catalyst‐free microwave conditions (140°C–165°C) to afford a series of novel nopinane‐annelated pyrazolo[3,4‐ b ]pyridines in isolated yields of 31%–68%. A reasonable mechanism for the condensation of 5‐aminopyrazoles with myrtenal is proposed. The structures of the newly synthesized compounds were established by spectroscopic methods, supported by density functional theory (DFT) calculations, and confirmed by single‐crystal x‐ray diffraction analysis. Owing to the presence of a rigid chiral nopinane framework and multiple nitrogen donor sites, the synthesized pyrazolo[3,4‐ b ]pyridines represent promising candidates for the development of chiral ligands for luminescent metal complexes.

The nuclear quadrupole resonance study of the electron-deficient substitution in the promising thermoelectric material FeGa3 resulting in the poorly studied Fe0.92Re0.08Ga3 and Fe0.92Mn0.08Ga3 compounds has been carried out. The doping of compounds of this structure type promotes the study of the dependence of the thermoelectric characteristics on the electronic structure and finally makes it possible to increase the thermoelectric efficiency, which is very important for applications. Both compounds exhibit pronounced signatures of the formation of an additional acceptor band inside the main band gap, which is determined by rhenium and manganese substituent atoms. Nuclear quadrupole resonance spectra, as well as nuclear spin–lattice relaxation and its temperature evolution, are significantly different for the compounds under study. This difference is due to different statistical distributions of substituent atoms (predominant formation of homo- and heterogeneous dumbbells in the rhenium- and manganese-substituted compounds, respectively) caused by their outer electron shells.

The 10 % substitution of arsenic for phosphorus in FeP represents an excellent example of the preservation of the crystal and helimagnetic structure, accompanied by stabilization of the latter. Although magnetic order in FeP 0.9 As 0.1 forms at lower temperature of 90 K, it turns out to be much more resistant to an external magnetic field. Namely, no spin-reorientation transition was observed up to 12 T, as well as any other distortion of the helical magnetic structure, in contrast to the parent compound FeP.

Recent studies have suggested that the commensal microbiome positively affects cancer prognosis and treatment outcomes. However, only a few strategies for regulating the microbiome composition have been reported. In this study, we identified gold(I) complexes that selectively inhibited nonbeneficial bacterial strains in vitro without affecting commensal Lactobacillus strains. In contrast, clinically used drugs demonstrated comparable effects on both commensal and noncommensal strains. Consistent with the in vitro results, the selected gold(I) complex induced favorable changes in the intratumoral and gastrointestinal microbiomes in vivo. Furthermore, its anticancer efficacy was found to be dependent on the composition of microbiome and correlated with the production of short-chain fatty acid bacterial metabolites. Structure-activity relationship studies have dissected the contribution of each structural component in both the in vivo efficacy and microbiome-modulating properties. Transcriptomic analysis of tumors revealed microbiome-associated gene signaling pathways. These findings provide valuable insights for future research on microbiome-modulating anticancer drugs, presenting potential avenues to optimize cancer treatment outcomes and mitigate side effects such as gastrointestinal dysbiosis. Furthermore, our study provides insights into the involvement of microbiome in the mechanism of action of metal-based chemotherapeutics.

A new 1,10-phenanthroline derivative bearing two (-)-borneol moieties (L) has been employed to design highly luminescent nitrate [LnL2(NO3)3] (Ln = Eu, Gd, Tb) and beta-diketonate [LnL(A)3] (Ln = Eu, Tb; A = hexafluoroacetylacetonate ion - hfac-, thenoyltrifluoroacetonate ion - tta-) complexes, containing 10- and 8-coordinated Ln3+ ions, respectively. The photoluminescent properties of the complexes have been studied in detail in solution and in the solid state at 298 and 77 K. The ligand L demonstrates the best sensitizing ability towards the Eu3+ ion, resulting in bright luminescence with a quantum yield of up to 0.70 observed for [EuL2(NO3)3]. The nature of the counterion has been found to play a key role in the ligand-to-Ln3+ energy transfer process. The influence of the molecular composition and the nature of the Ln3+ ion on the photophysical properties of the complexes is also discussed, as well as possible energy transfer pathways from the chromophore ligands to the lanthanide are considered.

Nopinane-annelated 4,5-diazafluorene and its derivatives can be easily converted into its mono-and diquaternized derivatives by reaction with methyl iodide and 1,2-dibromoethane respectively. 9,9-Dimethylated diquaternized dibromide salt has been converted into PF6-salt by anion-exchange reaction. The chemical structures of new compounds were proven by spectroscopic methods and X-ray study. Electrochemical and photophysical studies for diquaternized compounds were made. PF6-salt of dimethyldiazafluorene derivative demonstrates two-step reversible electrochemical reduction.

A rare example of the palladium-catalyzed sp3 C-H bond activation in a monoterpene-based compound has been observed in the reaction of PdCl2 with a (+)-3-carene-based ligand HL (HL=N-((1aS,3S,7bR)-1,1,3-trimethyl-7-phenyl-5-(pyridin-2-yl)-1a,2,3,7b-tetrahydro-1H-cyclopropa[f]quinolin-3-yl)acetamide), which yielded the [PdLCl] complex. In contrast to the vast majority of C(sp3)-H activation reactions which require prolonged heating and mixing due to the inert character of the corresponding bond, the reaction reported herein proceeds rapidly under mild conditions. A theoretical insight into the ligand deprotonation has been performed by DFT calculations. The mechanism of the C-H activation involves (i) simultaneous coordination of the CH3 group of HL to the Pd2+ ion and decoordination of the Cl- anion with consequent formation of a Cl⋅⋅⋅H-N hydrogen bond with the amide group, (ii) approximation of the out-of-sphere Cl- anion to one of the hydrogen atoms of the CH3 group mediated by the crane motion of the amide group and (iii) the ejection of the HCl molecule, which increases the entropy of the system and serves as a driving force for the reaction.

Samarium hydrogen iodate Sm(IO3)3HIO3 was successfully synthesized by the unconven-tional low-temperature solution-melt method, its structure was determined by X-ray dif-fraction analysis of single crystals. This compound crystallizes in the monoclinic space group P21/c with lattice parameters: a = 10.4637(6) Å, b = 7.4629(5) Å, c = 14.0174(13) Å, β = 110.53(0), Z = 6. In the studied structure, samarium atoms are surrounded by 8 ox-ygen atoms in a polyhedron in the form of a distorted square antiprism. The iodate groups are linked through common oxygen atoms of the SmO8 antiprism into a three-dimensional framework. The compound was characterized by X-ray diffraction, IR and NQR spectros-copy and EDX analysis.

Picoline ester of dimethylaminooxime of the (+)-3-carene series (L) and mononuclear complexes [ZnLCl2] (I) and [CdLCl2] (II) have been synthesized. In the structure of the complexes, the Zn2+ and Cd2+ ions coordinate three N atoms of the tridentate cyclic ligand L and two Cl atoms. The Cl2N3 coordination polyhedron of complex I is noticeably distorted. In the structure of complex II consisting of two independent molecules, the coordination polyhedron of one independent molecule is a square pyramid and the other is a trigonal bipyramid. The photophysical properties of solid samples of L, I and II have been studied. The ligand L exhibits emission that depends on the luminescence excitation wavelength. The lifetimes of the excited states of L are in the nanosecond range. Complexes I and II exhibit ligand-centered photoluminescence with luminescence quantum yields reaching 11

A series of novel hybride chiral macrocyclic compounds is described. The macrocyclic core of the new compounds is decorated with monoterpene fragments and includes 2 imine nitrogens and 2 tertiary amine nitrogens of the N,N-piperazine linkage as well as several repeating ethyleneoxy units resembling those of crown ethers. The macrocyclic compounds are prepared in moderate preparative yield (16–31%) upon treatment of a mixture of bis(α-amine oximes) and α,ω-dichloro derivatives of tri-, tetra- and hexa-ethylene glycol with sodium methylsulfinylmethylide. Chemical structure of the new macrocycles was established by a complex of spectroscopic techniques and X-ray analysis. The new macrocyclic compounds demonstrate remarkable selectivity with respect to Pd(II) and Au(III) and are able to efficiently extract these metals from acidic media containing a complex mixture of alkali metals, 3d-elements and noble metals. The features of conformational behavior, the ability to form complexes and the selectivity of extraction were studied using quantum chemical calculations at the DFT level. Based on the data obtained, a consistent scheme has been formulated to explain the features of extraction and the extraction selectivity of individual macrocycles.

We prepared an organically templated magnet, (enH(2))(0.5)VPO4OH (enH(2) = diprotonated ethylenediamine), hydrothermally and characterized its crystal structure by powder X-ray diffraction and Fourier-transform infrared spectroscopy, and its physical properties by magnetization, specific heat and nuclear magnetic resonance measurements and density functional theory calculations. (enH(2))(0.5)VPO4OH consists of uniform chains of V3+ (d(2), S = 1) ions and exhibits Haldane magnetism with spin gap Delta = 59.3 K from the magnetic susceptibility chi(T) at mu H-0 = 0.1 T, which is reduced to 48.4 K at mu H-0 = 9 T according to the P-31 shift. The NMR data evidence the formation of a spin-glass state of unpaired S = 1/2 spins at TS-G approximate to 3 K and indicate that the Haldane S = 1 spin chain segments are much longer in the organically templated magnet (enH(2))(0.5)VPO4OH than in the ammonium counterpart NH4VPO4OH. The single-ion anisotropy D and the interchain exchange J ' in (enH(2))(0.5)VPO4OH and NH4VPO4OH were estimated in density functional calculations to find them very weak compared to the intrachain exchange J.

Copper(II), zinc(II) and cadmium(II) complexes, [CuLCl2], [ZnLCl2] and [CdLCl2], with a new derivative of chiral alpha-aminooxime of natural (+)-limonene bearing a pycolyl group (L) were synthesized. The complexes are mononuclear, the L molecules act as N , N , N-tridentate chelating ligands. The computations support the fact that the N,N,N -chelation by a metal ion is thermodynamically preferred over the N,N -chelation for all complexes. The ligand L and the complexes [ZnLCl2] and [CdLCl2] exhibit fluorescence, with the emission spectra depending on the excitation wavelength. L emits in close to white region, while the Zn(II) and Cd(II) complexes demonstrate blue emission. Due to chelation-induced fluorescence enhancement effect, the fluorescence quantum yield increases when going from L to [ZnLCl2] and [CdLCl2]. The complex [CdLCl2] displays cytotoxicity against the HepG2 cell line (IC50 = 14.3 +/- 1.5 mu M), which is almost twice as high as that of cisplatin. The human breast adenocarcinoma cell line (MCF-7) is more sensitive to [CuLCl2] (IC50 = 43.4 +/- 0.4 mu M) than to [CdLCl2].

Конденсаты, получаемые при сушке древесины, представляют собой разбавленные водные растворы летучих веществ и по свойствам наиболее близки широко известным гидролатам. Анализ состава гидролатов часто проводится с использованием предварительной их экстракции органическими растворителями. Однако при этой процедуре могут теряться некоторые гидрофильные соединения, в результате чего результаты анализа не будут соответствовать нативному составу гидролата. В настоящей работе разработана модифицированная методика ГЖХ-анализа с предподготовкой образца, включающей экстракцию конденсата органическим растворителем, путем использования при анализе внутреннего стандарта гидрофобной природы. Разработанная методика опробована на конденсатах древесины сосны обыкновенной (Pinus sylvestris var. mongolica Litv.), но может применяться как к конденсатам, получающимся при сушке других древесных материалов и иного растительного материала, так и к гидролатам. The condensates obtained during wood drying are dilute aqueous solutions of volatile substances and are the closest in their properties to widely known hydrolates. The analysis of the composition of hydrolates is often carried out using their preliminary extraction with organic solvents. However, some hydrophilic compounds may be lost during this procedure, so that analysis results might not correspond to the native composition of the hydrolate. In this work, we have developed a modified technique of GLC analysis with preliminary sample preparation, including the extraction of condensate with an organic solvent, by using an internal standard of hydrophobic nature in the analysis. The developed technique has been tested on hydrolates of ordinary pine wood ( Pinus sylvestris var. mongolica Litv.), but it can also be applied both to condensates obtained during drying of other wood materials and other plant material, and to hydrolates.

In this work, we present the studies of structural phase transitions in Fe(Se,Te) crystals in the range of about 30 tellurium. We found a significant change in the properties of the ordered state of these compositions compared to the case of pure FeSe. The resistivity at low temperatures for the studied Fe(Se,Te) is proportional to the square of the temperature while for pure FeSe below the structural transition it depends almost linearly on temperature. The NMR data show a noticeable line broadening below the structural transition and an anomaly in the temperature dependence of the relaxation rate in the tellurium-substituted compounds, which was not observed in the pure FeSe. This reveals in quasi-binary compounds of iron-based superconductors a region of quantum criticality similar to that which exists when the nematicity of FeSe is suppressed under pressure and which precedes the emergence of high-temperature superconductivity in FeSe under hydrostatic pressure.

The condensates obtained during wood drying are dilute aqueous solutions of volatile substances and are the closest in their properties to widely known hydrolates. The analysis of the composition of hydrolates is often carried out using their preliminary extraction with organic solvents. However, some hydrophilic compounds may be lost during this procedure, so that analysis results might not correspond to the native composition of the hydrolate. In this work, we have developed a modified technique of GLC analysis with preliminary sample preparation, including the extraction of condensate with an organic solvent, by using an internal standard of hydrophobic nature in the analysis. The developed technique has been tested on hydrolates of ordinary pine wood (Pinus sylvestris var. mongolica Litv.), but it can also be applied both to condensates obtained during drying of other wood materials and other plant material, and to hydrolates.

We report a detailed study of the nature of the RuGa3 in-gap states by means of precision microscopic methods: nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR), and pump-probe spectroscopy. We observe a pronounced splitting of 69Ga nuclear spin-lattice relaxation curves below-40 K and between 70 and 145 K, although the corresponding NQR lines remain narrow over the entire tem-perature range under study. The slow relaxing component behaves like a typical phonon-induced relaxation way, while the fast relaxing one demonstrates signatures of paramagnetic (below-40 K) and activation (between 70 and 145 K) mechanisms. Moreover, additional Ga' and Ga" positions with anomalously low electric field gradient were revealed for the first time for IrIn3-type structure gallides, which stay almost unchanged, at least up to 77 K. The observed microscopic features are accompanied with in-gap states saturation or depleting, which is seen as the resistivity mechanism crossover at-180 K and electron lo-calization below 145 K evidenced by pump-probe spectroscopy. Based on our experimental results, we associate this pseudo-gap like behavior with inhomogeneously distributed electronic density defects, which manifest at both micro-(nuclear spin and phonon dynamics) and macroscale (bulk transport properties such as resistivity). (c) 2022 Elsevier B.V. All rights reserved.

Dipinodiazafluorenes are hybrid nopinane-annelated heterocycles whose molecules include a heterocyclic core of 4,5-diazafluorene condensed with fragments of terpene hydrocarbon, capable of selectively extracting palladium (88−100%), gold (42−96%) and ruthenium (8−19%) by single extraction from acidic aqueous solutions (pH 1.2) containing complex mixtures of 3d-elements and precious metals.

A comprehensive study of the intermetallic superconductor Mo8Ga41 was conducted by means of HRPXRD, abinitio calculations, NMR and NQR spectroscopy on Ga-69 and Ga-71 nuclei, as well as tunneling spectroscopy. All experimental methods used demonstrated the presence of an inherent surface superconducting phase in addition to the bulk superconducting phase. For the latter, the s-wave type single-gap superconducting behavior was observed with a slightly increased 2 Delta(0)/k(B)T(c) = 3.89 in agreement with the known enhanced electron-phonon coupling in this compound. From nuclear spin-lattice relaxation experiment, the estimated superconducting gap value of the surface phase was 2 Delta*(0) = 22.2 K, which corresponds to the T*(c) approximate to 6.3 K in the weak-coupling BCS limit. Meanwhile, the tunneling spectroscopy reveals similar values of T*(c) similar to 6.0-7.3 K for this surface phase. Thus, the known evidence of the Mo8Ga41 multi-gap behavior can be explained by the influence of the inherent surface superconducting phase.