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The first vanadium selenoiodide V4O(Se2)4I6·I2 was synthesized at a moderate temperature of 220 °C from V, Se, I2, and water. Its crystal structure (tetragonal space group P42/nbc, a = 11.838(1) A, c = 18.689(1) A) contains O-centered vanadium(IV) tetranuclear fragment [V4(μ4-O)(μ2-Se2)4(μ2-I)2I4], where the edges of the distorted tetrahedron V4 are bridged by four diselenide (Se2)2- and two iodide ligands; four terminal iodides coordinate V atoms additionally. This type of complex is known for Ti, Nb, and Ta but is new for vanadium. Magnetic susceptibility measurements of V4O(Se2)4I6·I2 showed four unpaired electrons on vanadium atoms at room temperature and drop of the effective magnetic moment at cool down, presumably due to partial electron pairing. Probability of this transition to the diamagnetic state is in accord with the calculated electronic structure.

New coordination compounds of copper(II) halides with 2-(3,5-dimethylpyrazol-1-yl)benzimidazole (L) are synthesized: CuLCl2 (I), [CuL2Cl]Cl⋅H2O⋅C2H5OH (II), and CuLBr2 (III). The compounds are characterized by IR spectroscopy, X-ray diffraction analysis, and static magnetic susceptibility. The crystal structure of compound II is determined by X-ray structure analysis (CIF file CCDC no. 2043452). The cytotoxic properties of ligands L and complexes I and II are studied.

In an assisted self-assembly approach starting from the [Mn6 O2 (piv)10 (4-Me-py)2 (pivH)2 ] cluster a family of Mn-Ln compounds (Ln=Pr-Yb) was synthesised. The reaction of [Mn6 O2 (piv)10 (4-Me-py)2 (pivH)2 ] (1) with N-methyldiethanolamine (mdeaH2 ) and Ln(NO3 )3 ⋅ 6H2 O in MeCN generally yields two main structure types: for Ln=Tb-Yb a previously reported Mn5 Ln4 motif is obtained, whereas for Ln=Pr-Eu a series of Mn7 Ln3 clusters is obtained. Within this series the GdIII analogue represents a special case because it shows both structural types as well as a third Mn2 Ln2 inverse butterfly motif. Variation in reaction conditions allows access to different structure types across the whole series. This prompts further studies into the reaction mechanism of this cluster assisted self-assembly approach. For the Mn7 Ln3 analogues reported here variable-temperature magnetic susceptibility measurements suggest that antiferromagnetic interactions between the spin carriers are dominant. Compounds incorporating Ln=NdIII (2), SmIII (3) and GdIII (5) display SMM behaviour. The slow relaxation of the magnetisation for these compounds was confirmed by ac measurements above 1.8 K.

In the plasma of pulsed high-voltage discharge, initiated between nickel electrodes in air, when the fluoroplastic is placed in the discharge gap, powder nanocomposite material has been synthesized. The nanocomposite contains NiF2 nanoparticles less than 5 nm in size, dispersed in a matrix consisting of carbon and fluorocarbon substances. The carbonaceous substance contains nanoscale disordered graphite-like regions. The fluorocarbon component of the composite contains fragments of PTFE molecules and fluorocarbon molecular fragments that differ in structure from PTFE molecule’s structure. After annealing the composite in air at 773 K, the initial nanocomposite is transformed into a nanocomposite containing nanosized PTFE and nanoparticles of NiF2 less than 5 nm in size, scattered in a matrix composed of nanographite and low-layer nanosized graphene, after aneling at 1173 K into a material containing NiO nanoparticles less than 10 nm in size. After annealing of the initial nanocomposite in argon atmosphere at 1073 K, the obtained nanocomposite contains Ni nanoparticles with sizes less than 5 nm and carbon and fluorocarbon components. The magnetic susceptibility of the unannealed nanocomposite is investigated. A transition to the antiferromagnetic phase at 73 K was detected. At T = 4K, exchange bias interaction of the AFM / FM type takes place in the composite. There is divergence of the FC and ZFC curves, which can be explained by the presence of a superparamagnetic phase or a spin glass phase in the sample. The field dependences of the magnetic susceptibility measured at T = 300 K show sharp changes that occur at certain values of the magnetic field. Elucidation of the nature of these changes requires additional research.

The influence of growth impurities (oxygen and carbon) on the thermalsdefect formation in silicon single crystals has been studied. Annealing was carried out in the temperature range 700-1100°C in steps of 50°C for 5 hours at each temperature. The magnetic, micromechanical and structural properties of annealed silicon single crystals have been experimentally studied. The distribution of defects formed at different annealing temperatures has been studied. The correlation between changes of magnetic susceptibility, microhardness and rearrangement of structural defects in crystals after their heat treatment is revealed. Concentrations and sizes of magnetically ordered clusters are estimated. Interpretation of the obtained experimental results is offered.

The superconducting magnetic separation was examined to reduce the volume of cesium contaminated soil by the Fukushima Daiichi nuclear power plant accident. By using superconducting high gradient magnetic separation, silt and clay with high radioactive concentration due to the large particle surface area per unit mass can be further separated into high-dose 2:1 type and low-dose 1:1 type clay minerals selectively. Here, we examined filter conditions to improve the magnetic separation performance in farmland soil that is rich in organic matter. The results of magnetic separation of uncontaminated soil suggested that the separation selectivity of 1:1 and 2:1 type clay minerals was larger with the filters with smaller wire diameter. On the other hand, it was found that it was difficult to magnetically separate 0–20 μm particles even with the filters with small wire diameter and high selectivity. To solve this problem, magnetic separation was performed under the same conditions on actual contaminated soil that was highly classified into 0–20 μm and 20–75 μm particles. As the result, it was found that the radioactivity can be further reduced by removed high-dose 0–20 μm particles and targeting the 20–75 μm particles.

This work describes an unexpected generation of a new 3D metal–organic framework (MOF), [Cu4(μ-Cl)6(μ4-O)Cu(OH)2(μ-PTA=O)4]n·2nCl-EtOH·2.5nH2O, from copper(II) chloride and 1,3,5-triaza-7-phosphaadamantane 7-oxide (PTA=O). The obtained product is composed of diamandoid tetracopper(II) [Cu4(μ-Cl)6(μ4-O)] cages and monocopper(II) [Cu(OH)2] units that are assembled, via the diamandoid μ-PTA=O linkers, into an intricate 3D net with an nbo topology. Magnetic susceptibility measurements on this MOF in the temperature range of 1.8–300 K reveal a ferromagnetic interaction (J = +20 cm–1) between the neighboring copper(II) ions. Single-point DFT calculations disclose a strong delocalization of the spin density over the tetranuclear unit. The magnitude of exchange coupling, predicted from the broken-symmetry DFT studies, is in good agreement with the experimental data. This copper(II) compound also acts as an active catalyst for the mild oxidation and carboxylation of alkanes. The present study provides a unique example of an MOF that is assembled from two different types of adamantoid Cu4 and PTA=O cages, thus contributing to widening a diversity of functional metal–organic frameworks., A unique 3D MOF composed of adamantoid tetracopper(II) and aminophosphine oxide blocks was assembled and fully characterized, and its magnetic and catalytic properties were investigated.

We report the structural, magnetic, and magnetocaloric properties of Bismuth (Bi)-substituted manganite La0.85-xBixNa0.15MnO3 (x=0, 0.1, 0.2, 0.25, and 0.3). X-ray diffraction data implicates the rhombohedral structure with $$ R\overline{3}c $$ R 3 ¯ c space group. Bi2O3 has helped in ensuring phase pure, densified compounds even at low sintering temperature and hence avoiding the evaporation of volatile sodium. The increase in grain size and decrease in magnetic transition temperature (TC) are due to the Bi chemical activity and electronic structure. The samples have shown indirect magnetic transformation from soft ferromagnet to canted ferromagnet/antiferromagnet with Bi. Griffiths phase-like behavior in the inverse magnetic susceptibility was observed for x=0.1; with further increase in Bi, the samples are found to develop the antiferromagnetic competing phase. The phenomenological model was used to model the thermomagnetic behavior of all the samples. The sample with x=0.1 shows an increase in magnetic entropy change upon Bi substitution and the maximum of magnetic entropy change is seen at 275K emphasizing its potential in room temperature magnetic refrigeration.

One new tri-nuclear nickel(II) coordination polymer, namely, [Ni3(μ3-O)(as-H2bptc)2(4,4′-bpy)2(H2O)4]n (H4bptc = 2,3,3′,4′-biphenyl tetracarboxylic acid, and 4,4′-bpy = 4,4′-bipyridine) has been synthesised under hydrothermal conditions, and its structure and properties have been characterised by X-ray single-crystal and powder diffraction, infrared spectrum analysis, elemental analysis, thermogravimetric analysis and magnetic susceptibility analysis. The single-crystal diffraction results showed that complex crystallised in the C2/c monoclinic space group was a 3D structure with tri-nuclear Ni(II) secondary building units, in which metal cations were in octahedral coordination geometries. The powder X-ray diffraction indicated that the complex was a pure phase and thermal analysis showed the excellent thermal stability of the complex. Additionally, variable temperature (2–300 K) magnetic measurements indicated antiferromagnetic coupling or spin inclination behaviour in the Ni3 core in the complex.

Reaction of [NiCl2(PnH)4] (1) (PnH=6‐tert‐butyl‐pyridazine‐3‐thione) with NiCl2 affords the binuclear paddlewheel (PW) complex [Ni2(Pn)4] (2). Diamagnetic complex 2 is the first example of a PW complex capable of reversibly binding and releasing NH3. The NH3 ligand in [Ni2(Pn)4(NH3)] (2⋅NH3) enforces major spectroscopic and magnetic susceptibility changes, thus displaying vapochromic properties (λ max(2)=532 nm, λ max(2⋅NH3)=518 nm) and magnetochemical switching (2: S=0; 2⋅NH3: S=1). Upon repeated adsorption/desorption cycles of NH3 the PW core remains intact. Compound 2 can be embedded into thin polyurethane films (2 P) under retention of its sensing abilities. Therefore, 2 qualifies as reversible optical probe for ammonia. The magnetochemical switching of 2 and 2⋅NH3 was studied in detail by SQUID measurements showing that in 2⋅NH3, solely the Ni atom coordinated the NH3 molecule is responsible for the paramagnetic behavior., The Ni2 paddlewheel complex can reversibly bind ammonia. This triggers spin‐state switching from dia‐ to paramagnetic and a change of color. Coordination of NH3 is fully reversible in solution, in solid state as well as encapsulated in a polyurethane foil.

Ferroelectric spin crossover (SCO) behavior is demonstrated to occur in the cobalt(II) complex, [Co(FPh-terpy)2 ](BPh4 )2 ⋅3ac (1⋅3 ac; FPh-terpy=4'-((3-fluorophenyl)ethynyl)-2,2':6',2''-terpyridine) and is dependent on the degree of 180° flip-flop motion of the ligand's polar fluorophenyl ring. Single crystal X-ray structures at several temperatures confirmed the flip-flop motion of fluorobenzene ring and also gave evidence for the SCO behavior with the latter behavior also confirmed by magnetic susceptibility measurements. The molecular motion of the fluorobenzene ring was also revealed using solid-state 19 F NMR spectroscopy. Thus the SCO behavior is accompanied by the flip-flop motion of the fluorobenzene ring, leading to destabilization of the low spin cobalt(II) state; with the magnitude of rotation able to be controlled by an electric field. This first example of spin-state conversion being dependent on the molecular motion of a ligand-appended fluorobenzene ring in a SCO cobalt(II) compound provides new insight for the design of a new category of molecule-based magnetoelectric materials.

The interaction of rhenium(III) halides Re3Br9 and Re3I9 with aqueous solution of sodium cyanide resulted in the formation of the first trinuclear halide-cyanide rhenium cluster complexes [{Re3X3}(CN)9]5-/[{Re3X3}(CN)9]4- (X = Br or I) crystallized as salts of the compositions Cs4Na[{Re3Br3}(CN)9]·5.25H2O (1), Cs4Na[{Re3I3}(CN)9]·6H2O (2), Cs4[{Re3Br3}(CN)9]·2H2O·0.5CsCl (3), and Cs4[{Re3I3}(CN)9]·(4). All of the compounds are stable in air in the solid state and in aqueous solution. The substitution of apical halide ligands in the parent compounds Re3X9 by cyanides led to reduction of the original metallocluster Re39+ (12 cluster valence electrons (CVEs)) to Re37+ (14 CVEs), forming the compounds 1 and 2. The apical CN- ligands affect the electronic structure of the Re3 metallocluster stabilizing reduced form. Complexes 1 and 2 represent the first examples of triangular rhenium clusters with the Re37+ metallocluster. The reaction of 1 and 2 with H2O2 resulted in formation of compounds 3 and 4 with the formal charge of the Re3 metallocluster equal to 8+, and no further oxidation to Re39+ occurred. The compounds were characterized by the X-ray diffraction analysis, NMR and UV-vis spectroscopies, mass spectrometry, cyclic voltammetry, and magnetic susceptibility measurements.

The magnetic susceptibility of the V3Si vanadium silicide synthesized from high-purity starting materials is measured in a 20−300 К temperature range. The dependence of the magnetic susceptibility of single-crystal on its orientation relative to the magnetic field is studied at room temperature, and the anisotropy of the magnetic susceptibility is found. Anomalies of different properties, which are observed in the 65–75 К temperature range, and the existence of anisotropy of the magnetic susceptibility are compared with those for pure vanadium; the genetic relationship (hereditivity) of many characteristics of the electronic structure of vanadium forming the silicide is noted.

The structural and magnetic properties of La 0.6 − x Y x Sr 0.4 MnO 3 (x = 0–0.3) manganite synthesized by the sol-gel method was systematically investigated. The structural properties of the samples were investigated using X-ray diffraction (XRD) patterns and confirmed by Rietveld refinement analysis. Using the energy dispersive X-ray (EDX) analysis, the atomic percentage of the elements in the samples was confirmed. To investigate the surface morphology of the specimens, a field emission scanning electron microscopy (FESEM) analysis of the specimens was performed. The effect of yttrium substitution on the magnetic properties of the samples was also investigated. The Curie constant, magnetic moment, blocking temperature, and Curie temperature (Tc) were calculated using the Curie-Weiss law and the magnetic susceptibility of the samples.

Reaction of 1 equiv of KN(SiMe3)2 with 9-fluorenone results in the formation of (Me3Si)N═C13H8 (1) in high yield after work-up. Addition of 1 equiv of phenol to 1 results in rapid desilylation and formation of 9-fluorenone imine, HN═C13H8 (2). Subsequent reaction of 2 with 1 equiv of LiNiPr2 results in deprotonation and formation of [Li(Et2O)]4[N═C13H8]4 (3) in good yield. Reaction of 1 equiv of KN(SiMe3)2 with 2-adamantanone for 7 days at room temperature results in the formation of (Me3Si)N═C10H14 (4) in good yield. Dissolution of 4 in neat MeOH results in rapid desilylation concomitant with formation of 2-adamantanone imine, HN═C10H14 (5). Subsequent reaction of 5 with 1 equiv of LiNiPr2 results in formation of [Li(THF)]4[N═C10H14]4 (6). Both 3 and 6 were characterized by X-ray crystallography. Finally, reaction of CrCl3 with 3.5 equiv of 6 results in formation of the [Cr2]6+ dimer, [Li][Cr2(N═C10H14)7] (7), which can be isolated in modest yield after work-up. Complex 7 features a Cr-Cr bond length of 2.653(2) A. Additionally, solid-state magnetic susceptibility measurements reveal strong antiferromagnetic coupling between the two Cr centers, with J = -200 cm-1.

Gadolinium stearate is synthesized in the form of a micropowder. Its composition is determined by elemental and energy dispersive X-ray analyses: [Gd(C17H35COO)3]·(H2O)2.42. The splitting parameters in the zero field (D and E) are determined for the EPR spectrum of the gadolinium stearate powder synthesized at 77 K. The magnetic susceptibility is calculated from the integral intensities of the EPR spectra of the gadolinium stearate powder recorded in a range of 77–293 K. The Curie temperature (θ = 0.16 K) and Weiss constant (С = 7.53 cm3 K mol–1) are determined. The effective magnetic moment is calculated (μeff = 7.8 ± 0.14 μВ), which is constant in the whole temperature range studied for the synthesized gadolinium stearate powder.

Two series of Bi2Mg1-xCoxNb2O9 and Bi2MgNb2-2xCo2xO9-δ preparations with pyrochlore structure were synthesized using solid phase method. It was found that solid solutions are formed in Bi2MgNb2-2xCo2xO9-δ series, foreign phases of MgNb2O6 and Bi5Nb3O15 are fixed in Bi2Mg1-xCoxNb2O9 samples, no impurity cobalt-containing phases were detected. The method of magnetic susceptibility and NEXAFS-spectroscopy investigated the electronic state and character of exchange interactions of cobalt atoms in solid solutions with the pyrochlore structure. According to X-ray spectroscopy and magnetic susceptibility of cobalt atoms in solid solutions in a dominant amount are in the charge state of Co(II) in the form of monomers and exchange-bound clusters mainly with antiferromagnetic type of exchange. Ceramics Co-doping of multicomponent bismuth niobate pyrochlore has at room temperature a high dielectric permeability of 84 and small dielectric losses of 0.001. The energy of activation of conductivity is equal to 0.75–1.03 eV. This type of ceramics with excellent dielectric properties can potentially be used as multilayer ceramic capacitors.

Composite materials that contain tetracationic hydrotalcite-like layered double hydroxide and a cobalt-iron spinel phase were prepared by coprecipitation from a solution of a mixture of magnesium, aluminum, cobalt(II), and iron(III) salts followed by hydrothermal treatment. The iron and cobalt contents in the samples were varied within a broad range. The thermal transformations of the prepared composites were examined by high-temperature X-ray diffraction, and the layered hydroxide phase was found to remain when heated up to 300°C. The specific magnetization and magnetic susceptibility of the materials were determined using a vibrating sample magnetometer; a rise in the iron and cobalt contents was found to increase the magnetization up to a certain limit. The obtained samples can be used as magnetic sorbents. The sorption capacity of materials was estimated using Congo red anionic dye as an example.

A cycle of experimental investigations is carried out, specifically, the measurements and analysis of field dependences of the static magnetic susceptibility in samples of single-crystal SiC thin films grown on the (100), (110), and (111) surfaces of a Si single crystal by the method of the self-consistent substitution of atoms due to the chemical reaction of silicon with carbon-monoxide (CO) gas. As a result of investigations in SiC structures grown on Si(110) and Si(111), the appearance of two quantum effects is found in weak magnetic fields at room temperature. These effects are, first, the formation of hysteresis of the static magnetic susceptibility and, second, the generation of Aharonov–Bohm oscillations in the field dependences of the static magnetic susceptibility. The first effect is associated with the Meissner–Ochsenfeld effect and the second effect, with the presence of microdefects in the form of nanotubes and micropores formed during the synthesis of structures in them under the SiC layer. In the SiC structures grown on Si(100), these effects are not detected, which is related to a different mechanism of SiC formation on the Si(100) surface.

A heteroligand complex of gadolinium stearate with acetylacetone is synthesized. Its composition is determined via thermogravimetry and energy dispersive analysis. Scanning electron microscopy shows that the synthesized material consists of layered particles with an average size of 50–60 μm. According to data from X-ray phase analysis, the complex of gadolinium stearate with acetylacetone has a tetragonal crystal lattice with parameters a = b = 24.03 A and c = 27.81 A. Diffuse light reflectance spectra of the complex are used to determine its band gap (3.04 eV). The magnetic susceptibility of the complex in the 2 MHz–2.5 GHz range is calculated from the experimentally measured impedances using a vector network analyzer.

Herein, two new Co(II) CPs, {[Co(H3L)(bpa)]·H2O}n (1) and {[Co2(H3L)2(phen)2(H2O)2]·3H2O}n (2) were hydrothermally obtained based on O-donor semi-rigid polycarboxylic acid ligand H5L (5,5’-((5-carboxy-1,3-phenylene)bis(oxy))diisophthalic acid) and N-donor coligands, such as bpa (1,2-bis(4-pyridyl)ethane), phen (1,10-phenanthroline hydrate). Both of them were studied by single crystal X-ray diffraction analysis, thermogravimetric analysis, infrared spectra, powder X-ray diffraction and variable-temperature magnetic susceptibilities. CP 1 features a one-dimensional chain, further stacked to a two-dimensional layer and three-dimensional structure through π···π stacking interactions and hydrogen bonds. CP 2 displays two-dimensional layers, which further extended into three-dimensional frameworks through C−H···π interactions and hydrogen bonds. In addition, variable-temperature magnetic susceptibility data were investigated, indicating that the CPs 1 and 2 exhibited antiferromagnetic interactions.

A new mononuclear complex Cu(tdp)Br2·MeCN (1, tdp = 2,2′-(1H-1,2,3-triazole-1,4-diyl)dipyridine) has been synthesized, which can transform to a 1D coordination polymer [Cu(tdp)Br2]n (2) under ambient conditions through an irreversible single-crystal-to-single-crystal transformation process. The loss of lattice MeCN molecules in 1 was accompanied by the generation of new covalent bonds and an increase in dimensionality from 0 to 1D, leading to a change in magnetic exchange couplings between the adjacent Cu(II) ions. Magnetic susceptibility measurements indicate that 1 exhibits ferromagnetic interactions between the adjacent Cu(II) centers, while the intrachain magnetic interactions between Cu(II) ions are antiferromagnetic within 2.

Francisites, Cu3M(YO3)2O2X (M = Bi or rare earth, Y = Se, Te, X = Br, Cl, or I), attract close attention from researchers because of their interesting magnetic properties, such as metamagnetic transitions in relatively weak magnetic fields and magnetic phase transitions with spin reorientation; they also can serve as model systems for the study of two-dimensional and frustrated magnetism. In this work, we have performed a low-temperature optical spectroscopic study of erbium francisite, Cu3Er(SeO3)2O2Cl. The observed splitting of spectral lines corresponding to f–f transitions in the Er3+ Kramers ion unambiguously indicates the magnetic ordering of the crystal at a temperature of TN = 37.5 K. The temperature dependence of the splitting of the ground doublet of the erbium ion is determined. The contributions of erbium to the heat capacity and to the magnetic susceptibility of Cu3Er(SeO3)2O2Cl are calculated.

We report on the growth of single crystals of an electron-doped titanium oxyfluoride, Li2Ti(O,F)3, employing high-temperature electrolysis of TiO2 with a eutectic Li2MoO4-LiF melt. Greenish octahedral-shaped crystals (∼30 μm in size) with a cubic rocksalt-type structure were successfully obtained by precisely tuning the applied voltage. The temperature-dependent magnetic susceptibility data revealed a paramagnetic behavior at low temperatures, ensuring the presence of Ti3+ ions (mean valence number of +3.78; F/Ti ∼ 0.15). The crystals exhibited clear visible-light absorption and produced H2 from water in the presence of a sacrificial reagent under UV-light irradiation. Li2Ti(O,F)3 more efficiently produced H2 compared with a nondoped oxyfluoride Li5Ti2O6F, likely due to the doped electrons for the former. This work highlights a promising electrochemical approach toward growing electron-doped oxyfluoride crystals.

In addition to previously studied {CuII3Gd6}, {CuII8Gd4}, {CuII15Ln7} and {CuII4Ln8} coordination clusters (Ln = trivalent lanthanide) containing pdm2− or Hpdm− ligands (H2pdm = pyridine-2,6-dimethanol) and ancillary carboxylate groups (RCO2−), the present work reports the synthesis and study of three new members of a fifth family of such complexes. Compounds [Cu5Ln4O2(OMe)4(NO3)4(O2CCH2But)2(pdm)4(MeOH)2] (Ln = Dy, 1; Ln = Tb, 2; Ln = Ho, 3) were prepared from the reaction of Ln(NO3)3·xH2O (x = 5, 6), CuX2·yH2O (X = ClO4, Cl, NO3; y = 6, 2 and 3, respectively), H2pdm, ButCH2CO2H and Et3N (2 : 2.5 : 2 : 1 : 9) in MeCN/MeOH. Rather surprisingly, the copper(II)/yttrium(III) analogue has a slightly different composition, i.e. [Cu5Y4O2(OMe)4(NO3)2(O2CCH2But)4(pdm)4(MeOH)2] (4). The structures of 1·4MeCN·1.5MeOH and 4·2MeOH were solved by single-crystal X-ray crystallography. The five CuII and four DyIII centres in 1 are held together by two μ5-O2−, four μ-MeO−, two syn,syn η1:η1:μ ButCH2CO2−, four η2:η1:η2:μ3 pdm2− (each of these groups chelates a CuII atom and simultaneously bridges two DyIII atoms through its two –CH2O− arms) and two μ-MeOH ligands. The four terminal nitrato groups each chelate (η1:η1) a DyIII centre. The five CuII atoms are co-planar (by symmetry) forming a bow-tie arrangement; the four outer CuII atoms form a rectangle with edges of 3.061(1) and 6.076(1) A. The four DyIII centres also form a rectangle that lies above and below the plane of the CuII centres, with edges of 3.739(1) and 5.328(1) A. The two strictly planar rectangles are almost perpendicular. Two trigonal bipyramidal μ5-O2− groups link the perpendicular Cu5 and Dy4 frameworks together. The molecule 4 has a very similar structure to that of 1, differences being the replacement of the two chelating nitrato groups of 1 by two chelating ButCH2CO2− ligands in 4 and the coordination polyhedra of the LnIII and YIII atoms (Snub diphenoids in 1 and biaugmented trigonal prisms in 4). Dc magnetic susceptibility data (χM) on analytically pure samples of 1–3, collected in the 300–2 K range, indicate that ferromagnetic exchange interactions dominate leading to large spin ground states. The χMT vs. T data for 4 suggest moderately strong antiferromagnetic CuII⋯CuII exchange interactions. Studies of the dynamic magnetic properties of the {Cu5Ln4} clusters show that 1 behaves as a SMM at zero field and 2 is a very weak field-induced SMM, while 3 exhibits only weak tails in the χ′′Mvs. T plots at various ac frequencies at zero dc field.

Abstract The tetrahedral cobalt(II) complex [CoL2](HNEt3)2 (I), where L is 1,2-bis(methanesulfonamido)benzene, exhibiting the properties of a single-molecule magnet is synthesized and characterized. The electronic structure parameters of complex I are determined by paramagnetic NMR spectroscopy. They completely reproduce the results of less available methods of studying single-molecule magnets. The value of axial anisotropy of the magnetic susceptibility estimated for complex I (Δχax = 34.5 × 10–32 m3 at 20°C) is record-breaking among all transition metal complexes studied by the NMR method, which provides wide possibilities for the use of complex I as a paramagnetic label for structural biology or as a contrast agent and even a temperature sensor for medical diagnostics. The data obtained indicate the advantages of paramagnetic NMR spectroscopy as a method of investigation of the magnetic properties and electronic structures of highly anisotropic transition metal complexes, which are precursors of many functional materials.

Using the deprotonated forms of the tetradentate phenol amine ligands 2-((((1-methylbenzimidazol-2-yl)methyl)(pyridin-2-ylmethyl)amino)methyl)phenol (HL1) and 2-(((pyridin-2-ylmethyl)(quinolin-2-ylmethyl)amino)methyl)phenol (HL2), dinuclear copper(II) complexes were synthesized. These ligands yielded two binuclear complexes with the composition [Cu2(Ln)2](ClO4)2 [n = 1, (1) and n = 2, (2)] and two mononuclear complexes with the compositions [Cu(HL1)(CH3CN)](ClO4)2 (3) and [Cu(HL2) (CH3CN)(OClO3)](ClO4) (4), which have been characterized using X-ray crystallography, UV-Vis, and magnetic susceptibility measurements. The magnetic susceptibility studies of 1 and 2 indicate moderate antiferromagnetic coupling between the CuII ions through the μ-phenoxo bridges [J = −38(2) and −145(1) cm−1, respectively], which is described by the Bleaney–Bowers dinuclear model. In contrast, 3 and 4 are devoid of any significant magnetic interactions between the mononuclear units. 3 and 4 show axial spectra typical of the d9 (dx2–y2 as the ground state) configuration. The dimer complexes 1 and 2 can be converted into the corresponding monomeric Cu(II) complexes 3 and 4via adding two equivalents of an acid, such as perchloric acid (HClO4), to a CH3CN solution of the dimer. The dimeric core can be regenerated via adding an equivalent of a base, such as triethylamine (Et3N). Time-dependent density functional theory (TD-DFT) calculations using the M06 functional were performed in order to rationalize the electronic structures of the complexes and to shed light on the origin of the observed electronic transitions. Additionally, DFT/B3LYP calculations helped us to unambiguously state the sign and magnitude of the magnetic coupling constants along with an approximation of the spin density distribution.

We describe the synthesis and characterization of a new trinuclear Ni(ii) Schiff base complex of formula [Ni3(L)2(NCS)2(OAc)2(CH3OH)2] (1) where HL is the 1 : 1 condensation product of 2-picolylamine and o-vanillin. The crystal structure of complex 1 shows that the two terminal Ni(ii) ions are connected to the central one through a phenoxido- and a syn-syn acetato bridge, giving rise to a very bent configuration in the Ni3-core. Magnetic susceptibility measurements show the presence of a weak antiferromagnetic coupling with J = -3.22(2) cm-1. We also report a magneto-structural correlation, performed with all the magnetically characterized Ni(ii) trimers with similar bridges, showing a linear dependence between the J value and the dihedral angle (θ) between the planes containing the Ni-O-Ni and the carboxylate bridges. The super-exchange interaction is investigated by extensive density functional calculations within the broken symmetry approximation which show good agreement with the experimental data. The analysis of the spin density distribution and the shape of the magnetically active single occupied molecular orbitals (SOMO) provide a mechanism of exchange coupling through the bridging groups.

This paper describes the synthesis and structures of three dinickel(II) complexes, namely [Ni2(μ-L)(μ-OH)](ClO4)2 (1), [Ni2(μ-H2L)(μ-OH)(NCS)3](NCS) (2), and [Ni2(μ-HL)(μ-OBz)(μ-H2O)(OBz)](ClO4)2·2.5H2O (3) (where HOBz = benzoic acid), with an end-off compartmental ligand (HL) obtained via the Schiff base condensation of 2,6-diformyl-4-methylphenol and N,N-dimethyldipropylenetriamine in methanol. Structural characterization reveals that both 1 and 2 are phenoxo- and hydroxo-bridged compounds, while complex 3 is a unique triple aqua-, phenoxo- and carboxylato-bridged dinickel(II) complex. Although similar bridging patterns to that found in 3 are known, the combination of aqua-, carboxylato- and phenoxo-bridging in a dinickel(II) complex has not been reported in the literature. Variable temperature magnetic susceptibility analysis reveals that the two nickel centres are antiferromagnetically coupled, with J values ranging from −12 to −143 K, in these complexes. The phenoxazinone-synthase-like activities of these complexes have been investigated using o-aminophenol as a model substrate in a methanol medium, as this area is yet to be explored for nickel(II) systems. Mass spectrometry and EPR spectroscopic studies were further carried out to gain insight into the course of the reaction, and the reactivity trend has been further explored. The present work highlights the novel triply bridged dinickel(II) complex and its magnetic properties and demonstrates a comparative biomimetic catalytic study relating to phenoxazinone synthase.

Two new dinuclear nickel(II) complexes, [(H2O)Ni(N3)(L1)(μ1,1-N3)Ni(L1)] and [(H2O)Ni(N3)(L2)(μ1,1-N3)Ni(L2)]·MeOH, derived from two isomeric Schiff base ligands, HL1 [2-{(2-(ethylamino)ethylimino)methyl}-6-ethoxyphenol] and HL2 [2-{(2-(dimethylamino)ethylimino)methyl}-6-ethoxy-phenol], have been synthesized and characterized. Variable temperature (2–300 K) magnetic susceptibility measurements indicate the presence of moderate ferromagnetic exchange coupling between nickel(II) centers. In each complex, antiferromagnetic exchange takes place through the phenoxido bridge and ferromagnetic through the μ1,1-azido bridge. The competitive interactions therefore reduce the overall magnetic coupling. In a theoretical complex, where the bridging azido ligand has been eliminated and the rest of the geometry is kept frozen, the magnetic coupling becomes antiferromagnetic which suggests that the ferromagnetic exchange occurs via the μ1,1-azido bridge. Mulliken population analysis and spin density plots clearly show that the spin distributed spherically in the Ni centers is due to the presence of one unpaired electron in both the and orbitals. The shape of the spin density at the bridging O-atom and azide evidences the participation of their p orbitals in the magnetic coupling. The SOMO is basically constituted by the orbital of one nickel(II) center with the participation of the azide π-system. The SOMO−1 is constituted by the orbital of the other nickel(II), an oxygen atom and the azide π-system.

The clathrate-I borosilicide K8−xBySi46−y (0.8 ≤ x ≤ 1.2 and 6.4 ≤ y ≤ 7.2; space group Pmn) was prepared in sealed tantalum ampoules between 900 °C and 1000 °C. By high-pressure preparation at 8 GPa and 1000 °C, a higher boron content is achieved (x = 0.2, y = 7.8). Crystal structure and composition were established from X-ray diffraction data, chemical analysis, WDX spectroscopy, and confirmed by 11B and 29Si NMR, and magnetic susceptibility measurements. The compositions are electron-balanced according to the Zintl rule within one estimated standard deviation. The lattice parameter varies with composition from a = 9.905 A for K7.85(2)B7.8(1)Si38.2(1) to a = 9.968(1) A for K6.80(2)B6.4(5)Si39.6(5).

The purpose of this paper is to understand the valorization of gold showings in the Seribaya deposit, western Mali. Samples taken from Air Core (AC) boreholes were subjected respectively to the magnetic susceptibility test and the X-ray fluorescence analysis. These results lead to the development of a simple methodology, based on signatures/indicators geochemical to identify lithology or to locate mineralization. We note that, compared to other chemical elements, Arsenic remains the most correlated with gold in the study area. Since this correlation remains weak (r = 0.16), it shows that Arsenic does not always accompany gold. There would be a generation of Arsenic related to mineralization, and other generations that would not be. The observation of the strip logs led to the identification of the lithologies (focusing on the immobile elements, Ti, V, Cr, Y, Zr) and the establishment of the alteration profile. Highly altered levels (Saprolite ± Saprock) are characterized by the disappearance of most mobile elements. A medium to strong correlation between gold mineralization and magnetic susceptibility measurements has been observed, in some places, and at depths. These mineralized intervals typically consist of quartz veins, suggesting that they have structural control over the mineralization. Gold mineralization is believed to be related to quartz veins. In addition, gold would be in paragenesis with a generation of Arsenic hosted in coarse sediments.

International audience; Assembly of dysprosium(III) salts with a multidentate ligand H3L ((2-hydroxy)-N'-((8-hydroxyquinolin-2-yl)methylene)-benzohydrazide) affords a variety of products with different topological structures, namely [Dy(H2L)(HL)]center dot CH3OH (1), [Dy-2(HL)(2)(C6H5COO)(2)(CH3OH)(2)]center dot 3CH(3)OH (2), [Dy-2(HL)(2)(NO3)(2)(DMF)(4)]center dot 4DMF (3), [Dy4L4(CH3OH)(4)]center dot 2CH(3)OH center dot 4H(2)O (4) and ([Dy-4(HL)(4)(C6H5COO)(4)(CH3OH)(H2O)]center dot 2CH(3)OH center dot CH3CN center dot H2O)(n) (5). The versatile and flexible coordination modes of phenoxo groups from salicylic hydrazide prove to be a key factor in the assembly of corresponding structures depending upon the reaction conditions. It is noteworthy that ligands HL2- act as a long-distance link and further connect the Dy-2 fragments into an infinite 1D chain due to the conformational flexibility resulting from the rotatable C-C bond in 5. Furthermore, the magnetic measurements were performed on all complexes. The dc magnetic susceptibility data evidence distinct magnetic coupling interactions in the dinuclear complexes 2 (antiferromagnetic) and 3 (ferromagnetic) despite their similar structures, and only complex 3 shows slow relaxation behavior of magnetization. Ab initio calculations and electrostatic potential analysis on complexes 2, 3, and three other complexes (6, 7, 8) incorporating different kinds of ligands reveal the important inter-relationship of magnetic anisotropy, magnetic coupling interactions and SMM properties.

The functionalized cage-like silsesquioxanes (POSSs) have attracted substantial interest because of their indisputable role in coordination chemistry as multi-donor ligands. In this paper, we report on the synthesis and structural properties of a novel POSS-based ligand created by the two mono-substituted cubic silsesquioxanes bound by trifunctional aromatic acyl chloride that may play the role of a multi-donor N,O-type ligand in copper(II) coordination chemistry. The solution absorption spectra of the obtained ligand with three different Cu2+ salts confirm the formation of coordination entities by the occurrence of characteristic d–d transition bands. The coordination mode depends on the pH of the environment and suggests oxygen donors at acidic pH and one or a maximum of two nitrogen atoms at higher pH values. Electron paramagnetic resonance (EPR) investigations are in agreement with UV-Vis studies, confirming possible coordination modes in solution. Direct current (DC) variable-temperature magnetic susceptibility measurements on polycrystalline samples of the resulting complexes were carried out in the temperature range of 1.8–300 K. The magnetic behavior of these complexes indicates a very weak antiferromagnetic interaction between copper(II) ions in the crystal lattice. From the magnetic point of view, the formed complexes can be considered as mononuclear species.

Gd3+ compounds receive special interest because of the maximum number of unpaired spins and they are useful in NMR spectroscopy and MRI. So, study on Gadolinium tri chloride has been reported here. The compound crystallizes in hexagonal structure. The particles are spherical and exhibit flake like structure. Low temperature magnetic study from 300 K to 20 K shows decrease of magnetic susceptibility with increase of temperature. M-H curve shows paramagnetic behavior. The compound can be used for UV filters and for optoelectronic applications. Low temperature magnetic study indicates cooperative interaction between the gadolinium spins in the compound.

Two new families of cobalt(II/III)–lanthanide(III) coordination aggregates have been reported: tetranuclear [LnIII2CoIII2L2(N-BuDEA)2(O2CCMe3)4(H2O)2]·(MeOH)n·(H2O)m (Ln = Gd, 1; Tb, 2; Dy, 3; n = 2, m = 10 for 1 and 2; n = 6, m = 2 for 3) and pentanuclear LnIII2CoIICoIII2L2(N-BuDEA)2(O2CCMe3)6(MeOH)2 (Ln = Dy, 4; Ho, 5) formed from the reaction of two aggregation assisting ligands H2L (o-vanillin oxime) and N-BuDEAH2 (N-butyldiethanolamine). A change in preference from a lower to higher nuclearity structure was observed on going across the lanthanide series brought about by the variation in the size of the LnIII ions. An interesting observation was made for the varying sequence of addition of the ligands into the reaction medium paving the way to access both structural types for Ln = Dy. HRMS (+ve) of solutions gave further insight into the formation of the aggregates via different pathways. The tetranuclear complexes adopt a modified butterfly structure with a more complex bridging network while trapping of an extra CoII ion in the pentanuclear complexes destroys this arrangement putting the Co–Co–Co axis above the Ln–Ln axis. Direct current (dc) magnetic susceptibility measurements reveal weak antiferromagnetic coupling in 1. Complexes 2 and 5 display no slow magnetic relaxation, whereas complexes 3 and 4 display out-of-phase signals at low temperature in ac susceptibility measurements. All compounds were analyzed with DFT and CASSCF calculations and informations about the single-ion anisotropies and mutual 4f–4f/4f–3d magnetic interactions were derived.

Two zirconyl complexes, [ZrO(AAPAAC)2(NO3)2] & [ZrO(AAPAAC)2Cl2], where (AAPAAC = 1,2-dihydro-1-phenyl-2,3-dimethyl-4-[2′,4′-pentanedione-3′-hydrazono]pyraol-5-one were synthesized and characterized by physico chemical and spectroscopic methods. The intramolecularly hydrogen bonded hydrazone structure of the ligand, AAPAAC was confirmed by spectral studies. The magnetic susceptibility measurements and low conductance data provide evidence for the monomeric and non-electrolytic natures of the complexes respectively. Thermal study of one of the complexes reveals its stability and anhydrous nature. The ligand shows neutral bidentate behavior in the complexes and the spectral studies confirm an octahedral geometry around the [ZrO]2+ in the complexes. The ligand and its complexes were screened for their antibacterial activities using disc diffusion method.

Two series of iron-containing solid solutions Bi2Mg1−x Fe x Nb2O9+δ and Bi2MgNb2−2x Fe2x O9−δ of pyrochlore structure were obtained by the traditional solid phase synthesis method. The electronic state and character of exchange interactions of iron atoms in solid solutions were investigated by methods of magnetic dilution and NEXAFS-spectroscopy. According to X-ray spectroscopy and magnetic susceptibility data, iron(III) atoms are distributed mainly in octahedral positions of niobium(V) and in a dominant amount are in the charge state of Fe(III) in the form of monomers and exchange-bonded clusters mainly with antiferromagnetic type of exchange. Differences in magnetic behavior of iron-containing solid solutions of both series have been revealed. Antiferromagnetic and ferromagnetic exchange can be realized between iron atoms, which, with increasing concentration of paramagnetic atoms and averaging structure distortions, becomes less significant. The parameters of exchange interactions in clusters and distribution of iron paramagnetic atoms depending on the concentration of solid solutions have been calculated.

The possibility of determining the magnetic susceptibility of metal inclusions from measured material parameters of binary composites using known mixing models is considered. A model is proposed that considers the inversion of the matrix structure of the Maxwell–Garnett model for a filler concentration close to the percolation threshold. It is determined that restructuring the composite occurs gradually in the region of transition concentrations the width of which is an additional parameter determined from the experiment. The proposed model is compared with the effective medium model in terms of the dependences of complex susceptibility on filling and frequency. The reliability of the model is illustrated by processing the material parameters of composites with carbonyl nickel as a filler measured in the frequency range 0.1–20 GHz.

Earlier, we experimentally showed a significant effect of oxygen on the magnetic and structural properties of Mn5Ge3 due to the formation of a Nowotny phase of Mn5Ge3Ox. Here, in continuation of this study, we present a theoretical study of the magnetic and electronic properties of Mn5Ge3 and Mn5Ge3Dx (D = B, C, O). It was found that hexagonal Mn5Ge3 is a ferromagnetic metal with two nonequivalent manganese atoms in the structure. Our ab initio calculations also predict the existence of a spin-crossover in Mn5Ge3 under pressure. Impurities reduce saturation magnetization and electrical and thermal conductivity; however, the magnetic susceptibility and Curie temperature increase. Microscopic mechanisms of the effect of the impurities on the magnetic and electronic properties Mn5Ge3 are discussed.

International audience; A multi-analytical methodology is implemented to characterize several sieving fractions of industrial samples of Black Mass (BM) powders originating from the thermo-mechanical treatment of cylindrical and prismatic-type spent nickel metal-hydride (Ni-MH) batteries. Elemental analyses of 17 elements (including C and O) indicate that the elemental composition of the powders (greater than93 %wt) does not depend on the battery type nor on the sieving fraction. XRD analyses evidence several phases (including Ni, NiO, CeO2 and C) but their quantification is not possible. Beyond these standard characterisations, magnetic susceptibility measurements demonstrate that the amount of metallic nickel versus nickel oxide increases with the sieving fraction, and that powders from prismatic-type batteries contain twice as much metallic nickel than cylindrical ones. Thanks to statistical analysis (based on clustering algorithms) of an electron probe µ-analysis (EPMA) compositional map, the complete methodology allows us to propose a full phase distribution for the BM particles. Three types of particles are identified and quantified. They originate from the partial oxidation of the battery components (anode active mass, anode current collector, cathode active mass and cathode current collector). The whole picture highlights the joint importance of battery ageing mechanisms, thermal deactivation and BM sieving steps on powder composition

Dinuclear copper(II) complex [Cu2(L)2(μ2-1,1-N3)2(N3)2] (1) with double μ1,1-azido bridges and polynuclear nickel(II) complex [Ni(L)(μ2-1,1-N3)(μ2-1,3-N3)]n (2) with alternate double μ1,1-azido and μ1,3-azido bridges [L = 1-amino-2-(dimethylamino)ethane, N 3 − = azide ion] have been synthesized and were characterized by physicochemical and spectroscopic methods. X-ray structural analysis revealed that each Cu(II) center of 1 adopts a distorted square-pyramidal geometry with a CuN5 chromophore ligated through two N atoms of L, two N atoms of double bridging (μ1,1-N3), and one N atom of terminal azide ion. On the other hand, each Ni(II) center around the asymmetric unit of 2 adopts a distorted octahedral geometry with a NiN6 chromophore ligated through two N atoms of L, two N atoms of double μ1,1-N3, and two N atoms of double μ1,3-N3 bridges. The adjacent nickel centers are connected to alternate double μ1,1-N3 and double μ1,3-N3 bridges, affording a one-dimensional (1D) polymeric chain structure. Temperature-dependent magnetic susceptibility measurements evidenced a dominant antiferromagnetic interaction between the metal centers of both complexes 1 and 2.

New iron(II) complexes with 2,6-bis(benzimidazol-2-yl)pyridine (L) and closo-borate(2–) anions—[FeL2][B10H10] ⋅ 2H2O and [FeL2][B12H12] ⋅ H2O—have been synthesized. The complexes have been characterized by static magnetic susceptibility measurements, electronic (diffuse reflectance spectra), IR, and EXAFS spectroscopy, and X-ray diffraction analysis. A study of the μeff(T) dependence in the temperature range 80–500 K has shown that the complexes exhibit a high-temperature spin crossover 1А1 ⇔ 5Т2.

New heteroligand cobalt(II), iron(II), and manganese(II) complexes of the M(3,6-SQ)2L type bearing 3,6-di-tert-butyl-o-benzosemiquinonato ligands (3,6-SQ) and 2,2'-biquinoline or 1,4-di-tert-butyl-1,4-diazabutadiene-1,3 as neutral ligands (L) have been synthesized and characterized. It was shown on the basis of the magnetic susceptibility measurements and spectroscopic studies that all complexes contain metal(II) ions in the high-spin state and two radical-anionic o-semiquinonato ligands. It was found in the result of analysis of magnetic susceptibility temperature dependence by magnetic coupling parameters modeling that the antiferromagnetic ligand-ligand coupling takes place in the cobalt(II) and iron(II) complexes, while antiferromagnetic metal-ligand interactions dominate in the manganese(II) complexes.

Three new hetero-metallic copper(II)-manganese(II) complexes, [(CuL)2 Mn3 (C6 H5 CO2 )6 ] (1), [(CuL)2 Mn(CH3 CO2 )2 ] (2), and {[(CuL)2 Mn(C6 H5 CH2 CO2 )2 ] ⋅ 2CH3 CN} (3), have been synthesized using [CuL] as ''metalloligand'' (where H2 L=N,N'-bis(2-hydroxynaphthyl-methylidene)-1,3-propanediamine). Single-crystal structural analyses show an almost linear penta-nuclear structure for complex 1 where a square planar [CuL] unit is connected to each of the two terminal MnII ions of a linear, centrosymmetric [Mn3 (benzoate)6 ] unit through the double phenoxido bridges. Both complexes 2 and 3 possess a linear tri-nuclear structure where two terminal square-pyramidal [CuL] units are bonded to the central MnII ion through double phenoxido oxygen atoms along with a syn-syn bridging acetate (for 2)/phenyl acetate (for 3). All three complexes exhibit catecholase, and phenoxazinone synthase-like activities under aerial conditions. For catecholase like activity, the turnover numbers (kcat ) are 595, 40, and 205 h-1 whereas, for phenoxazinone synthase like activity, the turnover numbers are 25, 4, and 11 h-1 for complexes 1-3, respectively. The mechanism of both catalytic oxidase activities is proposed on the basis of mass spectral evidences. Variable-temperature (2-300 K) dc molar magnetic susceptibility measurements of 1 reveal antiferromagnetic interactions between the Cu-Mn centres (J1 =-29.3 cm-1 ), and also between the Mn-Mn centres of the [Mn3 (benzoate)6 ] unit (J2 =-0.68 cm-1 ). On increasing the magnetic field at 2 K, its ground spin state changes from S=3/2 to S=5/2 at 4 T, attributable to the low value of J2 which makes the excited spin states close in energy with the ground spin state. Complexes 2 and 3 show antiferromagnetic coupling interactions between the Cu-Mn pairs with J values of -9.51, and -5.32 cm-1 , respectively.

One of the long-standing challenges in experimental physics is the observation of room-temperature superconductivity1,2. Recently, high-temperature conventional superconductivity in hydrogen-rich materials has been reported in several systems under high pressure3–5. An important discovery leading to room-temperature superconductivity is the pressure-driven disproportionation of hydrogen sulfide (H2S) to H3S, with a confirmed transition temperature of 203 kelvin at 155 gigapascals3,6. Both H2S and CH4 readily mix with hydrogen to form guest–host structures at lower pressures7, and are of comparable size at 4 gigapascals. By introducing methane at low pressures into the H2S + H2 precursor mixture for H3S, molecular exchange is allowed within a large assemblage of van der Waals solids that are hydrogen-rich with H2 inclusions; these guest–host structures become the building blocks of superconducting compounds at extreme conditions. Here we report superconductivity in a photochemically transformed carbonaceous sulfur hydride system, starting from elemental precursors, with a maximum superconducting transition temperature of 287.7 ± 1.2 kelvin (about 15 degrees Celsius) achieved at 267 ± 10 gigapascals. The superconducting state is observed over a broad pressure range in the diamond anvil cell, from 140 to 275 gigapascals, with a sharp upturn in transition temperature above 220 gigapascals. Superconductivity is established by the observation of zero resistance, a magnetic susceptibility of up to 190 gigapascals, and reduction of the transition temperature under an external magnetic field of up to 9 tesla, with an upper critical magnetic field of about 62 tesla according to the Ginzburg–Landau model at zero temperature. The light, quantum nature of hydrogen limits the structural and stoichiometric determination of the system by X-ray scattering techniques, but Raman spectroscopy is used to probe the chemical and structural transformations before metallization. The introduction of chemical tuning within our ternary system could enable the preservation of the properties of room-temperature superconductivity at lower pressures. Room-temperature superconductivity is observed in a photochemically synthesized ternary carbonaceous sulfur hydride system at 15 °C and 267 GPa.

Magnetic susceptibility of a series of hypoeutectic Al-Yb alloys has been investigated in a wide temperature range from 300 to 1650 K. A step-like drastic change in the magnetic susceptibility at melting point has been discovered for the first time. The anomaly is interpreted as a temperature-induced valence transition. The substitution aluminum by gallium shifts the valence transition to room temperature. The valence states of ytterbium in both systems are discussed for solid and liquid phases.

Aim and objective Platinum (II) and platinum (IV) of pyrophosphate complexes have been prepared and characterized to discover their potential as antitumor drugs. This study was conducted to prepare and characterize new ternary platinum (II) complexes with formamidine and pyrophosphate as an antitumor candidate. Materials and methods The complexes have been characterized by mass, infrared, UV-Vis. spectroscopy, elemental analysis, magnetic susceptibility, thermal analyses, and theoretical calculations. They have been tested for their cytotoxicity, which was carried out using the fastcolorimetric assay for cellular growth and survival against MCF-7 (breast cancer cell line), HCT- 116 (colon carcinoma cell line), and HepG-2 (hepatocellular cancer cell line). Results All complexes are diamagnetic, and the electronic spectral data displayed the bands due to square planar Pt(II) complexes. The optimized complexes structures (1-4) indicated a distorted square planar geometry where O-Pt-O and N-Pt-N bond angles were 82.04°-96.44°, respectively. Results also show that all complexes are neutral, stable and non-hygroscopic and have noticeable cytotoxicity with IC50 (μM): 0.035-0.144 MCF-7(breast cancer cell line), 0.042-0.187 HCT-116 (colon carcinoma cell line), and 0.063-0.168 HepG-2 (hepatocellular cancer cell line). Moreover, the results show that the complex (4) has the best IC50 value. Conclusion The complexes showed noticeable cytotoxicity and are considered as promising antitumor candidates for further applications.

Summary High saturation magnetization, hysteresis-less long linear response range, and resistance to device fabrication conditions are figures of merit for magnetic materials. Despite advances in materials research, many high-saturating micro- and nanomagnetic materials are hysteresis-prone, have short linear ranges, and are sensitive to oxidation, resulting in device inefficiencies in high-frequency electronics and unpredictable responses in magnetic sensing applications. Holmium oxide is a promising material because of its high magnetic susceptibility, but synthetic options are limited, with low-temperature magnetism incompletely characterized. Here, we present physical vapor deposition synthesis and material characterization of polycrystalline holmium oxide thin films. The product has saturation magnetization exceeding 2 Tesla, linear range (μ0H) also exceeding 2 Tesla, zero magnetic remanence and coercivity, and resistance to harsh processing conditions including oxygen plasma and concentrated hydrofluoric acid etching, making these thin films ideal for fabricating next-generation nanoscale magnetic devices in advanced scientific and engineering applications.