O-centered tetranuclear vanadium selenoiodide [V4OSe8I5]infinity (1) was synthesized by an ampoule method from the elements with addition of water. Its X-ray crystal structure (space group C2/c, a = 21.146(2) & Aring;, b = 5.8953(5) & Aring;, c = 18.735(1) & Aring;, beta = 126.421(2)degrees, V = 1879.4(3) & Aring;3, T = 150 K, Z = 4) is a packing of chains built from O-centered tetranuclear [V4(mu 4-O)(mu-Se2)4(mu 4-I)2/2I4] fragments. In the O-centered fragment, vanadium atoms form a distorted tetrahedron around an oxygen atom, V atoms are bridged by four mu 2-(Se2)2- and two I- ligands. The latter iodide ligands bridge the neighboring fragments, thus forming a chain [V4(mu 4-O)(mu-Se2)4(mu 4-I)2/2I4]infinity. The synthesis of the chain [V4OSe8I5]infinity takes place at the temperature of 290 degrees C, while at lower temperatures (220-250 degrees C) molecular compounds [V4OSe8I6]X form. The direct 'cluster to chain' transformation is also observed and discussed in this work. Electrical resistance of the [V4OSe8I5]infinity polycrystalline pressed sample shows that the compound 1 is a narrow gap semiconductor, which is in agreement with the DFT calculations.

Using XPS and DFT, we have studied a series of octahedral rhenium cluster compounds: ternary thiobromides Re6S4+nBr10-2n, n = 0, 1, 3, 4 and alkali metal salts of anionic complexes [Re6S4+nBr10-n]n-, n = 1-4. These two series contain [Re6S4+nBr4-n] cluster cores, which are the building blocks of both discrete complexes and polymeric compounds, and have the same coordination polyhedron of rhenium atoms. The constancy of the coordination polyhedron of Re reduces the effect of structural differences and allows to study the change in the electronic state of the rhenium atoms of the Re6 metallocluster with increasing number of less electronegative (compared to bromine) sulfur atoms in the cluster core. This change results in the decrease in the binding energy (BE) Re 4f7/2 in the series of anionic complexes [Re6S4+nBr10-n]n-. A similar dependence is observed in the series of ternary thiobromides. Re6S8Br2 falls out of this trend, which is explained by a change in the type of binding of the cluster cores. The BE S 2p3/2 of the sulfide ligands and the BE Br 3d5/2 of the bromide ligands decrease as the number of sulfur atoms in the cluster core and the charge of anionic complexes increases. The difference in BE values for the inner Bri and apical Bra bromide ligands shows that the inner ligands are more covalent and the apical ligands are more ionic. Calculated energies of the Re 4f, S 2p, Br 3d orbitals confirm the general tendency for the energy to decrease as the number of sulfur atoms in the cluster cores increases. Calculation of the atom charges for discrete complexes [Re6S4+nBr10-n]n-, showed that with increasing number of sulfur atoms in the cluster cores, the negative charge of the ligands increases, while the charge of the rhenium atoms remains unchanged. This suggests that the chemical shift of the Re4f binding energy is determined by the potentials of the surrounding atoms (Madelung potential) and that the chemical shift of the ligands depends on the charge of the atom.

This research aims to explore the potential application of this approach in the production of biosensor chips. The biosensor chip is utilized for the identification and examination of early-stage lung cancer cells. The findings of the optical microscope were corroborated by the field emission scanning electron microscopy, which provided further evidence that the growth of MoS 2 is uniform and that there is minimal disruption in the electrode, hence minimizing the likelihood of an open circuit creation. Furthermore, the bilayer structure of the produced MoS 2 has been validated through the utilization of Raman spectroscopy. A research investigation was undertaken to measure the photoelectric current generated by three various types of clinical samples containing lung cancer cells, specifically the CL1, NCI-H460, and NCI-H520 cell lines. The findings from the empirical analysis indicate that the coefficient of determination (R-Square) for the linear regression model was approximately 98%. Furthermore, the integration of a double-layer MoS 2 film resulted in a significant improvement of 38% in the photocurrent, as observed in the device's performance.

Abstract In this study, a biosensor chip was fabricated using MoS2, which is used to detect and analyze the level of cancerization in lung cancer cells. Cancer is the leading cause of mortality worldwide, accounting for over 10 million deaths in 2022, or roughly one death in every six patients. Consequently, society places a high value on cancer prevention and treatment methods. Thus, developing the quickest method to detect cancer and provide correct analytical information for the clinic at an early stage of cancer is very important. It has constantly been the focus of reciprocal relationships and collaborative efforts between the academic and medical sectors. The MoS2 thin film was grown on the light-absorbing layer substrate of silicon-based solar elements through chemical vapor deposition and combined with a self-designed serrated interdigitated electrode (SIE) through the carrier transport mechanism of photogenerated charges. The three types of lung cancer cell clinical samples—CL1, NCI-H460, and NCI-H520 cell lines were subjected to photoelectric flow measurement. The experimental results showed that the R-Square of the linear fitting curve was approximately 98%. In addition, the device was enhanced by 38% when a double-layer MoS2 film was added. GSSGs reaction analysis can be further enhanced.

The interaction of graphene fluoride with 2-phenylbenzimidazole has afforded a new benzimidazole-functionalized graphene material. It has been shown that performing the reaction in sulfolane in the presence of pyridine provides higher degree of functionalization. The target product formation has been confirmed by means of elemental analysis as well as IR and Raman spectroscopy.

We have perfected processes for the synthesis of lanthanum, gadolinium, and yttrium oxyselenides by heating oxides in flowing hydrogen and selenium vapor. The optimal selenidation temperature is 700°C for lanthanum, 850°C for gadolinium, and 900°C for yttrium. Subsequent annealing of the materials in flowing hydrogen at 1000°C makes it possible to remove trace levels of amorphous selenium and impurity phases containing diselenide groups.

This review analyzes literature on polymeric transition metal polychalcogenides of group IV–VII This review systematizes literature data on polymeric polychalcogenides of group IV–VII transition metals (TiS3, VS4, NbSe3, MoSx, ReS4, etc.). It covers the structural characteristics of crystalline compounds and the proposed structural models of amorphous phases. The latest advances in the synthesis of these low-dimensional materials at the nanoscale are presented. Their chemical properties are discussed, in particular, those arising from the presence of the dichalcogenide bonds. It is emphasized that the properties of the S–S (or Se–Se) groups largely determine the distinctive features of polychalcogenides and the unusual phenomena observed in them. In particular, these groups play an important role in the performance of electrode materials in metal-ion batteries, photo- and electrocatalysts for hydrogen evolution reaction, and mercury vapour sorbents based on transition metal polychalcogenides, which is also addressed in this review. The bibliography includes 304 references.

Intercalation compounds of fluorinated graphite that form when graphite interacts with a strong fluorinating agent have been known for several decades. However, there was not enough understanding about their structures and outstanding stabilities, given that guest molecules contained in them are very active fluoroxidants. In this study, we build a structural model of an ordered crystal of the stage-II intercalation compound C2F∙xClF3 basing on the chain model of the C2F layers. The constructed model explains well the experimentally observed composition of the product of gas-phase fluorination of natural graphite (C2F∙0.13ClF3). Experimental X-ray diffraction patterns of the C2F∙xClF3 compound were studied using the constructed models. Phase composition, crystal structure parameters and sizes of ordered regions were refined. The results show that in the C2F∙xClF3 compound every second or third gap between the C2F layers is filled with guest molecules, but ordered regions are nanosized, and an amorphous disordered phase exists as well. Noncovalent bonding interactions between the components of the compound (C2F…ClF3, C2F…C2F) were examined using topological analysis of the electron density distribution in the framework of Bader's quantum theory, followed by evaluation of the interaction energies. The calculated characteristics prove that the intercalation of ClF3 molecules into the C2F interlayer space is an energetically favorable process.

Pyrolysis of a mixture of monosilane with light hydrocarbons in an argon atmosphere in a cyclic compression reactor was used to synthesize nanoparticles with a crystalline silicon core and a carbon shell. The resulting powders were tested as an anode material for lithium-ion batteries. It is shown that the maximum reversible electrochemical capacity is 603 and 242 mA h/g at current densities of 0.05 and 2 A/g, respectively.

A series of rhenium compounds with the octahedral cluster core {Re6S8-xBrx} (x = 0–4): with molecular and polymeric structure were obtained. In these compounds the cluster core composition varies monotonically, the geometry of the cluster and the rhenium coordination polyhedron are retained unchanged, while the symmetry of the cluster changes. The vibrational spectra (Raman and IR) were recorded and analyzed for compounds with all possible S/Br ratios in the cluster core. The group vibrations of clusters were attributed with the use of DFT calculations of vibrational spectra. It is shown that the set of main characteristic bands is retained in both ionic and polymeric compounds regardless of the composition and the symmetry of the cluster core while the observed vibration frequencies of these bands depend on the S/Br ratio in the cluster core. In particular, the group Re–S stretching vibrations (A1g(S8) and T2g(S8) modes) shifted to higher frequencies with the increase in the number of Br atoms in the cluster. The difference in the connectivity in polymeric compounds leads to an increase in the number of bands in the spectra and to the disappearance of the A1g(Br) modes.

The connection between the peak of density of electronic states at ~ 0.4 eV below the Fermi level and the localization of charge carriers at compression of the height of CuO 5 pyramids has been found by a comparison of experimental angle-resolved photoemission spectra data for Y 0.9 Ca 0.1 Ba 2 Cu 3 O 6.8 single crystal and calculations of the electronic structure in a framework of the density functional theory. Both experiment and calculation are performed using 34.6 and 90.2 eV photon energy. The excitation energy does not have any noticeable influence on the peak of density of electronic states. Crystal structure distortions on the crystal surface result in observation of localized electronic states below the temperature of superconducting transition.

In this study, we present the growth of monolayer MoS2 (molybdenum disulfide) film. Mo (molybdenum) film was formed on a sapphire substrate through e-beam evaporation, and triangular MoS2 film was grown by direct sulfurization. First, the growth of MoS2 was observed under an optical microscope. The number of MoS2 layers was analyzed by Raman spectrum, atomic force microscope (AFM), and photoluminescence spectroscopy (PL) measurement. Different sapphire substrate regions have different growth conditions of MoS2. The growth of MoS2 is optimized by controlling the amount and location of precursors, adjusting the appropriate growing temperature and time, and establishing proper ventilation. Experimental results show the successful growth of a large-area single-layer MoS2 on a sapphire substrate through direct sulfurization under a suitable environment. The thickness of the MoS2 film determined by AFM measurement is about 0.73 nm. The peak difference between the Raman measurement shift of 386 and 405 cm(-1) is 19.1 cm(-1), and the peak of PL measurement is about 677 nm, which is converted into energy of 1.83 eV, which is the size of the direct energy gap of the MoS2 thin film. The results verify the distribution of the number of grown layers. Based on the observation of the optical microscope (OM) images, MoS2 continuously grows from a single layer of discretely distributed triangular single-crystal grains into a single-layer large-area MoS2 film. This work provides a reference for growing MoS2 in a large area. We expect to apply this structure to various heterojunctions, sensors, solar cells, and thin-film transistors.

O-centered vanadium(IV) selenoiodide V4OSe8I6 center dot 3,5-dimethylpyrazole was synthesized in a sealed glass ampoule at moderate temperature 220 degrees C from the mixture of V, Se, I-2, small quantity of water and 3,5-dimethylpyrazole. The X-ray single crystal structure of the compound was solved. The crystal structure includes O-centered tetranuclear complex [V-4(mu(4)-O)(mu-Se-2)(4)(mu-I)(2)I-4] in which vanadium atoms are bridged by diselenide (Se-2)(2-) and iodide I- groups; four terminal iodides coordinate vanadium atoms additionally. Molecules of 3,5-dimethylpyr-azole form non-covalent contacts with iodine and selenium atoms of the V4OSe8I6 complexes. Once compounds V4OSe8I6 center dot 3,5-dimethylpyrazole and V4OSe8I6 center dot I-2 contain similar electroneutral coordination molecular fragment V4OSe8I6, we present here a discussion of spectroscopic properties as well as thermal behavior. Comparing XPS data, both compounds contain vanadium complexes with major V 2p binding energies very similar to each other, and almost equal binding energies in XPS Se 3d and I 3d showing their forms of (Se2-)(2) and I-, respectively. Thermolysis character of these compounds revealed higher stability of V4OSe8I6 center dot I-2 than V4OSe8I6 center dot 3,5-dimethylpyrazole, that indicates a greater stability of the system of non-covalent contacts involving iodine molecules than 3,5-dimethylpyrazole.

Reaction pathways are found for electronic structural rearrangements in thiometallates [ M S 4 ] n – ( M = V, n = 3; Mo, n = 2; Re, n = 1), which do not contradict the hypothesis about the possible electron transfer from sulfide ions S 2– to metal centers with a corresponding decrease in metal atomic charges and the formation of disulfide ions of the (S 2 ) 2– type. The obtained results are compared with similar results for the same series of oxometallates [ M O 4 ] n – .

O-centered vanadium(IV) selenoiodide V4OSe8I6·dmp was synthesized in a sealed glass ampoule at moderate temperature 220°С from the mixture of V, Se, I2, small quantity of water and 3,5-dimethylpirazol (dmp). The X-ray single crystal structure of the compound was solved (sp. gr. P-1, a = 11.4037(8) Å, b = 11.7897(8) Å, c = 12.5107(8) Å, α = 90.293(2)°, β = 114.820(2)°, γ = 110.379(2)° V = 1408.29(17) Å3, Z = 2, R1 = 0.0221). The crystal structure includes O-centered tetranuclear complex [V4(μ4-O)(μ-Se2)4(μ-I)2I4] in which vanadium atoms are bridged by diselenide (Se2)2– and iodide I– groups; four terminal iodides coordinate vanadium atoms additionally. Dmp molecules form non-covalent contacts with iodine and selenium atoms of the V4OSe8I6 complexes. Here we discuss synthesis of the title compound as well as spectroscopic (XPS and vibrational) characteristics of the V4OSe8I6 molecular complex in the complexes V4OSe8I6·dmp and V4OSe8I6·I2.

It is well known that the benchmark electrocatalysts for OER in alkaline solution are RuO2 and IrO2; however, the high cost, scarcity, and instability of these metal oxides impede their ample use in OER processes, and this has fueled the search for cheap Earth-abundant elements which are equally efficient for application as electrocatalysts in OER. The present work reports the use of hydrothermal and calcination methods for the synthesis of nanocomposites made up of Ni and/or Co salts and urea in combination with MoSe2 and MoS2 and their application as efficient and stable electrocatalysts for OER in alkaline solution. The NiCoMoSe, NiCoMo, CoMoSeS, and CoMo nanocomposites constructed in the present study presented high OER electrocatalytic activity and stability mainly as a result of the following: the combination of N atoms bonded to Ni and/or Co (and Mo); the electrons released from the oxidation of Co from the 2(+) to 3(+ )state, Ni oxidation from the 2(+) to 3(+ )state, and Mo oxidation from the 4(+) to 6(+ )state; and the metal oxides (CoMoO4, NiCo2O4, Co2Mo3O8, and Co3O4) supported on MoS2 nanosheets and MoSe2 nanoribbons which contributed to a decrease in charge transfer resistance, apart from keeping the ECSA values relatively low.

Inorganic phosphors based on rare earth elements are commonly used as scintillation materials due to their high chemical and radiation resistance. In this work, we study gadolinium oxyselenide as a new phosphor material. The work describes a facile synthesis method for Gd2O2Se. Single crystal structure of this compound was determined for the first time: sp.gr. P3m1 with a = 3.8911(4) angstrom and c = 6.8829(8) angstrom. Gd2O2Se is stable in the inert atmosphere and melts at 2075 +/- 20 degrees C. This material is also stable when heated in air up to 720 degrees C. with the following oxidation and weight increase. This mass increase can be explained by the oxidation of Se2- to Se4+. Further temperature increase above 952 degrees C leads to a sharp mass loss and the final mass of sample corresponds to full oxidation of Gd2O2Se to gadolinium oxide. The band gap of the material was estimated to be 3.6 eV. Photoluminescence spectrum for Gd2O2Se:Tb3+ shows the characteristic transitions in Tb3+ ion with the most intense green emission that corresponds D-5(4) -> F-7(J) transitions.