The paper presents the synthesis and investigation of the magnetic properties of a new coordination polymer [Cu4((3-Ala)4(OH)2(ClO4)2]n(H2O)2n (1), the structure of the obtained compound was studied by SC-XRD, PXRD and IR spectroscopy. Compound 1 consists of 1D chains formed by [Cu4((3-Ala)4(OH)2(ClO4)2] subunits, which are further linked into a 3D network by hydrogen bonds. The core of each subunit is a tetranuclear [Cu4(OH)2]6+ cluster with a 'chair-like' topology and antiferromagnetic intrafragment superexchange. These structural units are linked into a 1D polymer chain via the carboxylate groups of (3-alanine in a syn-anti coordination. According to the results of quantum chemical calculations, this specific coordination accounts for the ferromagnetic interaction between the tetranuclear fragments. This fact significantly distinguishes magnetic properties of 1 from other compounds with a & laquo;chair-like & raquo; fragment. The (3-alanine ligand in complex 1 exhibits various functions: monodentate and bridging coordination, which is clearly manifested in the splitting of v(COO-) bands in the IR spectrum. The absorption bands of the IR spectrum are assigned based on isotopic substitution and quantum chemical calculations. In the DR spectrum of complex 1 transitions corresponding to two Cu(II) coordination polyhedra with different crystal field parameters were detected. The antibacterial activity of polymer 1 against E. coli Delta tolC, E. coli lptDmut and E. coli K12 strains was investigated.

Redox mediators (RMs) are highly effective in reducing a charge overpotential and preventing rapid degradation of lithium-oxygen (Li-O2) batteries. In this work, cyclometalated Ru (II) complexes with various substituents (RuXR, R = CH3, H, CN) were synthesized and investigated as promising RMs. Substituent variation in these compounds enable tuning the redox potential to identify the most efficient mediator. The complexes demonstrated a significant reduction in charge potential by up to 500 mV and exhibited higher efficiency than tetrathiafulvalene (TTF), ferrocene (Fc), and decamethylferrocene (Me10Fc). Kinetic studies of the key process catalyzed by the mediator during Li-O2 cell charging-namely, the oxidation of Li2O2-showed that an increase in the redox potential of similar compounds leads to greater RM efficiency. However, despite their high efficacy, the Ru complexes are unstable towards singlet oxygen (1O2), which forms during cycling of Li-O2 cells. These results provide important design guidelines for redox mediators in Li-O2 batteries, emphasizing the need to balance Li2O2 oxidation kinetics and chemical robustness.

A series of new heterometallic lanthanide(iii) and nickel(ii) metallacryptates [LnNi(Val)26][An]3 with l-valine (Ln = La—Gd, HVal = l-valine, An = BF4−, ClO4−, PF6−, NO3−, I−, I3−) were synthesized. The structures and composition of the complexes were studied by powder X-ray diffraction, single-crystal X-ray diffraction, IR spectroscopy, UV-Vis spectroscopy, diffuse reflectance spectroscopy (DRS), and elemental analysis. The composition and structure of the complexes in solution and their optical properties were investigated by UV-Vis absorption spectroscopy, DRS, and mass spectrometry. The crystal field splitting parameters Δo were determined. The conditional stability constants of a series of the complexes in methanol were evaluated. The stability of the complexes depends on the amino acid nature and is presumably associated with a change in the inductive l-effect of the amino acid functional group. The sphere packings of the complexes with different amino acids were determined and the anion preferences were established. Unlike the previously synthesized complexes with glycine and alanine, the complexes with l-valine are preferentially precipitated by small inorganic ions, making it possible to use the cationic complex [LnNi(Val)26]3+ for the selective extraction of early lanthanides(iii) from solution.

High-spin Fe 3+ ion imbedded in the extended solid displays field-induced slow relaxation of magnetization with enhanced relaxation time values.

The decomposition processes of plutonium hydroxo compounds formed under ozonation conditions in MOH (M = Li, Na, K) solutions of various concentrations were studied by UV–Vis spectroscopy using a modified nonlinear least squares method. The influence of the nature of alkali on the kinetics and mechanisms of spontaneous reduction of alkaline solutions of hydroxo compounds of plutonium(VII) was discovered. This influence and the “anomalies” in the UV–Vis spectra for ozonized plutonium solutions are associated with the presence in the systems of iron compounds in the form of impurities in commercially available LiOH, NaOH and KOH (analytically pure, chemically pure, and ultrapure grade). Even trace amounts of impurities in alkaline solutions of plutonium compounds change the mechanisms of their reduction through the active participation of iron in redox processes. They include the oxidation of iron to ferrate(VI) ions FeO42–, followed by reduction to Fe3+, probably through the stage of formation of an intermediate with a hydroxo derivative of plutonium(VI). As a result of the analysis of large arrays of spectral data, the spectra of individual components corresponding to compounds of plutonium(VI, VII) and iron (VI) were isolated.

A series of 32 heterometallic ionic complexes [CeNi 6 (Ala) 12 ][(Ln x Ce 1 – x )(NO 3 ) 3 (OH) 3 (H 2 O)] (Ln = Tb, Ho, Er, Tm, Yb, Lu) have been synthesized and characterized by XRD and IPC-MS. The dependence of the degree of substitution of lanthanides in the anionic position on the nature of Ln 3+ and precipitation conditions has been determined. The processes occurring during the formation of the complexes have been studied by UV-Vis, diffuse reflectance electronic spectroscopy, and ICP-MS. Based on these data, a model of equilibria in the system was proposed to explain the increase in the degree of substitution of Ln in the anionic position in the lanthanide series and with a decrease in the concentration of Ce and Ln in the solution from which precipitation is performed.

Синтезированы и охарактеризованы при помощи РФА и ИСП-МС 32 гетерометаллических ионных комплекса [CeNi 6 (Ala) 12 ][(Ln x Ce 1 – x )(NO 3 ) 3 (OH) 3 (H 2 O)] (Ln = Tb, Ho, Er, Tm, Yb, Lu). Определена зависимость степени замещения лантанидов в анионной позиции от природы Ln 3+ и условий осаждения. Процессы, протекающие в ходе образования изученных комплексов, исследованы методами ЭСП, ЭСДО и ИСП-МС. На основании этих данных предложена модель равновесий в растворе, объясняющая увеличение степени замещения Ln в анионной позиции по ряду лантанидов и при снижении концентрации Ce и Ln в растворе, из которого проводится осаждение.

A series of cyclometalated complexes of ruthenium (II) with four different substituents in the aryl fragment of benzimidazole was synthesized in order to study the effect of substituent donation on the electronic structure of the substances. The resulting complexes were studied using X-ray diffraction, NMR spectroscopy, MALDI mass spectrometry, electron absorption spectroscopy, luminescence spectroscopy, and cyclic voltammetry as well as DFT/TDDFT was also used to interpret the results. All the complexes have intense absorption in the range of up to 700 nm, the triplet nature of the excited state was confirmed by measurement of luminescence decay. With an increase in substituent donation, a red shift of the absorption and emission bands occurs, and the lifetime of the excited state and the redox potential of the complex decrease. The combination of these properties shows that the complexes are excellent dyes and can be used as photosensitizers.

New complex [RuL(Dmdcbp)2]PF6 (I) is synthesized by the consecutive reactions of [Ru-p-cymene]2Cl4 with 3,3',5,5'-tetramethyl-1,1'-biphenyl-4,4'-bipyrazole (L) and 4,4'-dicarboxy-2,2'-bipyridine in a methanol–chloroform medium. The composition of complex I is confirmed by NMR and elemental analysis, and the optical and luminescence properties of the complex are studied. Ligand L is characterized for the first time by X-ray diffraction (CIF file CCDC no. 2118676). Quantum chemical calculations in terms of the density functional theory are performed for the interpretation of the absorption and emission spectra. Complex I is promising for using as a photosensitizer.

Three novel lanthanide complexes with the ligand 4,4-difluoro-1-(1,5-dimethyl-1H-pyrazol-4-yl)butane-1,3-dione (HL), namely [LnL3(H2O)2], Ln = Eu, Gd and Tb, were synthesized, and, according to single-crystal X-ray diffraction, are isostructural. The photoluminescent properties of these compounds, as well as of three series of mixed metal complexes [EuxTb1-xL3(H2O)2] (EuxTb1-xL3), [EuxGd1-xL3(H2O)2] (EuxGd1-xL3), and [GdxTb1-xL3(H2O)2] (GdxTb1-xL3), were studied. The EuxTb1-xL3 complexes exhibit the simultaneous emission of both Eu3+ and Tb3+ ions, and the luminescence color rapidly changes from green to red upon introducing even a small fraction of Eu3+. A detailed analysis of the luminescence decay made it possible to determine the observed radiative lifetimes of Tb3+ and Eu3+ and estimate the rate of excitation energy transfer between these ions. For this task, a simple approximation function was proposed. The values of the energy transfer rates determined independently from the luminescence decays of terbium(III) and europium(III) ions show a good correlation.

Cyclometalated Ru(ii) complexes with 2-arylbenzimidazole antenna ligands bearing electron-donor/withdrawing substituents and anchoring 4,4'-dimethoxycarbonyl-2,2'-bipyridine have been prepared and their structure, optical and electrochemical properties have been studied. The complexes possess enhanced light-harvesting characteristics compared to those of the standard N719 dye and absorb light up to 750 nm. In addition, they demonstrate reversible redox behavior with Ru3+/Ru2+ potentials being finely tuned by the change of the electron-donating ability of cyclometalated ligands. After a mild hydrolysis of dimethoxycarbonyl groups the excellent optical properties of the complexes remain unchanged and they show good efficiency when tested in dye-sensitized solar cells.

A novel β‐diketone ligand bearing a thiophene moiety and an anchoring Ph‐COOCH 3 unit has been designed, prepared and used in synthesis of cyclometalated benzimidazole‐based iridium(III) complexes for application in dye‐sensitized solar cells (DSSC). The replacement of traditional 4,4'‐dicarboxy‐2,2'‐bipyridine by this aromatic β‐diketone results in excellent tuning the redox potentials and excited state properties of these Ir III complexes, one of which exhibits good efficiency when used as a dye in DSSC. All the complexes demonstrate reversible redox behavior, with oxidation potentials (Ir 4+ /Ir 3+ ) strongly depending on the electron‐donor/withdrawing nature of the substituents in the cyclometalated ligands. Surprisingly, the latter has just a little effect on their luminescence spectra, in which structured emission bands are observed. Time‐resolved spectroscopic studies in combination with DFT calculations show that the complexes emit light by mixed 3 MLCT– 3 LC excited states predominantly composed of the diketone ligand‐centered triplet state.

The dependence of lead silicate glass color, applied using copper(ii) ions, on lead content in the glass, the nature of the alkali metal, and copper content was studied. It was shown that the principal contribution to the color is made by the shift of the fundamental absorption edge, which correlates with the amount of lead and copper ions. According to EPR results for glasses with the studied compositions, copper ions have a tetragonally distorted octahedral coordination environment, which does not change considerably with composition. The Cuii d—d-transition bands also do not undergo considerable changes.

New cyclometalated neutral iridium(III) complexes [Ir(L) 2 (dbm)] have been synthesized, where L is 2-arylphenanthroimidazoles with various electron-donor or acceptor substituents, dbm is dibenzoyl-methane. The compositions and structures of the ligands and complexes have been studied by X-ray diffraction and high-resolution mass spectrometry. In the absorption spectra of the complexes, a bathochromic shift of the absorption maxima is observed with an increase in the electron donor properties of the ligands. All the complexes show the reversible redox behavior; redox potentials fall in the range of 0.8–1.6 V. The combination of the obtained results allows us to consider the synthesized compounds as potential photosensitizers in solar cells.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Iridium(III) is often considered to be one of the most inert octahedral metal ions. Herein we present a phenanthroimidazole-based bis-cyclometalated iridium(III) chloride undergoing a facile chloro ligand exchange with iodine, in a gas-solid reaction under ambient conditions. Monitoring the progress of the reaction by X-ray diffraction analysis reveals the crystal-packing-induced exceptional stereoselectivity of this topochemical transformation. The results provide excellent opportunities to modulate the geometry and kinetic properties of cyclometalated iridium(III) complexes that may be very promising in catalysis and design of anticancer agents.

The paramagnetic properties of compounds resulting from the synthesis of nanohydroxyapatite in the presence of Fe(III) ions have been studied by electron paramagnetic resonance, Mössbauer spectroscopy, and magnetochemistry. Based on the obtained results on the mechanism of the reaction between an orthophosphoric acid solution and an aqueous calcium hydroxide suspension, we have found conditions for incorporating Fe(III) impurity ions into hydroxyapatite. We have studied samples differing in the sequence in which reagents were mixed and in hydroxyapatite crystallite formation conditions. It has been shown that, in all instances, the composition and properties of the iron-containing phases in the composites depend significantly on both synthesis and heat treatment conditions.