BiCl3 Research Articles

Design and simulation of strong cesium copper–bismuth chloride double perovskite solar cells with an efficiency exceeding 25% for plateau areas

Plateau regions are known for their strong ultraviolet radiation and extended sunlight hours, making them ideal settings for the photovoltaic industry. The development of efficient lead-free perovskite solar cells suitable for high-altitude environments is critical because of the harmful effects of ultraviolet radiation and the toxicity of lead. The cesium copper–bismuth chloride double perovskite with an indirect band gap of 1.36 eV and low toxicity can serve as an ideal absorber for high-efficiency solar cells for ultraviolet and visible absorption. Both density functional theory and a solar cell capacitance simulator were employed to calculate the photoelectric properties of cesium copper–bismuth chloride and optimize device performance. The ideal layer thicknesses of 450 nm for the electron transport layer, 600 nm for the perovskite layer, and 30 nm for the hole transport layer, with respective carrier densities of 1019, 1017, and 1018 cm−3, enabled the optimal device to achieve a short-circuit current of 34.31 mA/cm2, an open-circuit voltage of 0.88 V, a fill factor of 85.3 %, and a power conversion efficiency of 25.62 %, maintaining a fill factor of > 80 % and a power conversion efficiency of > 20 % even at 400 K. Optimized parameters of the absorber and carrier transport layer amplify the built-in electric field and reduce carrier recombination, thereby improving device performance. These findings demonstrate cesium copper-bismuth chloride perovskite solar cells significantly enhance solar energy use in high-altitude environments, providing guidance for the development of other solar cells.

In Situ Stabilization of Bi Nanoparticles into the Nanopores of Modified Montmorillonite: Efficient Heterogeneous Catalysts for Reduction of 4-Nitrophenol.

Here, we report the in situ generation of Bi nanoparticles (BiNPs) into a nanoporous matrix by impregnation of bismuth chloride and subsequent reduction with sodium borohydride. The nanoporous matrix was created by acid activation of natural montmorillonite clay under controlled conditions with the aim that it may serve as a host for BiNPs. The characterization of stabilized BiNPs was done by using Fourier-transform infrared (FTIR), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and field emission scanning electron microscopy-energy dispersive X-ray (FESEM-EDX) techniques. The TEM study reveals that the BiNPs with an average particle size of 7.16 nm are well-distributed on the surface of the acid-activated montmorillonite clay. The synthesized BiNPs exhibited excellent catalytic activity for the degradation of 4-nitrophenol (4-NP) in aqueous medium with remarkable results. The degradation of 4-NP to 4-aminophenol (4-AP) at 25 °C, in the presence of sodium borohydride, brought about almost 100% conversion in 6 min with a rate constant of 0.20098 s-1 that follows the pseudo-first-order kinetics.

Dual-Template-Directed Zero-Dimensional Bismuth Chlorides: Structures, Luminescence, Photoinduced Chromism, and Enhanced Proton Conductivity.

Zero-dimensional (0D) hybrid organic-inorganic bismuth halides have attracted immense scientific interest as promising candidates for lead-free materials. Here, by using a typical solvothermal method, two mixed-cation-phase 0D hybrid bismuth chlorides of [HPDA][H2PDA]BiCl6 (1) and [Hbzim][H2PA]BiCl6 (2) (PDA = bis(4-pyridyl)amine, bzim = benzimidazole, PA = 2-picolylamine) have been assembled based on a series of organic amine guests. Both compounds exhibit interesting photoluminescence phenomena, in which compound 1 exhibits a double emission property of blue fluorescence and yellow-green phosphorescence simultaneously, while compound 2 exhibits wide-band yellow-green emission under visible light excitation. The luminescence mechanism is explained by experiments and theoretical calculations. In view of the fact that halometallate units and the conjugated nitrogen heterocyclic systems can act as electron donors and electron acceptors, respectively, both compounds exhibit free radical-driven photochromism induced by electron transfer under xenon lamp irradiation at room temperature. In addition, benefiting from abundant hydrogen bond networks in structures, the two compounds show significant temperature-dependent proton conduction behavior in the range of 298-343 K, and the proton conductivity of both compounds is significantly improved after light irradiation. Our study demonstrates two novel hybrid mixed-cation-phase 0D hybrid bismuth halides with photoluminescence, photochromism, and photomodulated proton conduction properties, which enriches the dual-template-directed metal halide system and provides a feasible scheme for the synthesis of photoresponsive smart materials.

The transport of bismuth in HCl-bearing aqueous vapour and low-density aqueous supercritical fluids: Implications for natural systems

Hydration by H2O clusters has been shown to be an important means of transporting metal complexes in hydrothermal vapours and low-density supercritical aqueous fluids. However, the effect of hydration on the transport of relatively volatile metal complexes such as those involving bismuth and chloride has not been evaluated. This effect is important to evaluate because bismuth is a key pathfinder element for gold in many intrusion-related gold ore-forming systems, where low-density supercritical aqueous fluids and vapour may play an important role in metal transport. Here, we present the results of experiments investigating the solubility of BiOCl(s) and the speciation of bismuth in HCl-bearing aqueous vapour and low-density supercritical aqueous fluids at temperatures between 250 and 400 °C and pressures of 5 to 296 bar. Two gaseous bismuth species formed in the HCl-bearing fluids (X(HCl) > 0.0005), namely BiCl3(g) and BiCl3(H2O)n(g). Our data clearly show that BiCl3(g) is highly volatile at low water fugacity (between 30 and 110 bar) and acts as an unhydrated gas molecule. At higher water fugacity, the gaseous BiCl3(g) reacts with water to form hydrated BiCl3(H2O)n(g) species. Significantly, the stability of hydrated bismuth chloride species, BiCl3(H2O)n(g), with low hydration numbers is lower than that of the unhydrated species, BiCl3(g), resulting in a decrease in bismuth solubility with increasing f(H2O). However, at a water fugacity great than 30–110 bar, that increases with increasing temperature, the hydration number and the solubility of hydrated species BiCl3(H2O)n(g) increase with increasing water fugacity or the density of the fluid. Consequently, unhydrated gaseous bismuth species increase in importance with increasing temperature and become dominant at temperatures > 450 °C in fluids that have low density (<0.10 g/cm3). Hydrated bismuth chloride species are dominant in fluids having higher density (0.10–0.34 g/cm3). The overarching conclusion of this study is that aqueous low-density supercritical fluids, which exsolve from magmas to form intrusion-related gold deposits, can transport bismuth in concentrations (up to hundreds ppm) sufficient to form economic deposits.

Dencichine attenuates the virulence of Fusobacterium nucleatum by targeting hydrogen sulfide-producing enzyme.

Oral opportunistic pathogen Fusobacterium nucleatum can participate in various disease processes through the metabolite hydrogen sulfide, such as halitosis and colorectal cancer. The object of this study is to identify inhibitor capable of suppressing Fn1220, which is the principal hydrogen sulfide-producing enzyme in F. nucleatum. Through this inhibition, we aim to reduce the hydrogen sulfide production of F. nucleatum, consequently diminishing its virulence. Employing molecular docking techniques for inhibitor screening, we identified dencichine as the monomeric compound from Chinese medicine exhibiting the lowest binding energy to Fn1220 among a set of 27,045 candidates, and evaluated in vitro the ability of dencichine to inhibit hydrogen sulfide production using bismuth chloride method. Additionally, we investigated its impact on key virulence factors, including biofilm formation, hemolysis, and adhesion factors of F. nucleatum, using the crystalline violet method, sheep blood method, and RT-qPCR, respectively. Furthermore, we assessed the influence of dencichine on the lifespan of Caenorhabditis elegans. Results showed that dencichine was a suitable inhibitor of the Fn1220 of F. nucleatum, which significantly inhibited the production of virulence factors, e.g., biofilm, hemolysin, FadA, and Fap2 of F. nucleatum and improved the survival of C. elegans. We successfully identified the inhibitor of the enzyme Fn1220, dencichine, which inhibited the production of hydrogen sulfide and attenuated the virulence of F. nucleatum and holds promise as a potential therapeutic avenue for addressing oral diseases, e.g., halitosis in the future.

Intermolecular Forces Regulating the Phase-Transition Temperatures in Organic-Inorganic Hybrid Materials.

Organic-inorganic hybrid phase-transition materials have attracted widespread attention in energy storage and sensor applications due to their structural adaptability and facile synthesis. However, increasing the phase-transition temperature (Tc) effectively remains a formidable challenge. In this study, we employed a strategy to regulate intermolecular interactions (different types of hydrogen bonds and other weak interactions), utilizing bismuth chloride as an inorganic framework and azetidine, 3,3-difluoro azetidine, and 3-carboxyl azetidine as organic components to synthesize three compounds with different Tc values: [C3H8N]2BiCl5 (1, 234 K), [C3H6NF2]3BiCl6 (2, 256 K), and [C4H8O2N]3BiCl6 (3, 350 K). 1 is a one-dimensional chain structure and 2 and 3 are zero-dimensional structures. Analysis of the crystal structure and the Hirshfeld surface and 2D fingerprints further suggests that the intermolecular forces are efficiently modulated. These findings emphasize the efficacy of our strategy in enhancing Tc and may facilitate further research in this area.

Experimental determination of the electrochemical properties of bismuth chloride in eutectic LiCl–KCl and LiCl–KCl–CaCl2 molten salts

Experimental determination of the electrochemical properties of bismuth chloride in eutectic LiCl–KCl and LiCl–KCl–CaCl2 molten salts

Exploring Bismuth (III) Sulpha Drugs Schiff Base Coordination Complexes: Design, Synthesis, Structural, Spectroscopic Characterization, and Biological Evaluations

The present study aimed to prepare and then evaluate the tetra and coordinated Bismuth (III) complexes [BiCl2 (L)] (LH = N, O donor Schiff base employed by the condensation of 1-acetyl-2-naphthol and 2-acetyl-1-naphthol using sulpha drugs as ligand) were derived by the reaction of bismuth (III) trichloride and sodium salt of an N, O donor Schiff base ligand and characterized. The authenticity of all the synthesized ligands and their Bi (III) complexes had been identified by microanalysis, various spectroscopic techniques like FT-IR, 1H NMR, and elemental analysis. The spectral evidence of the complexes has revealed the bidentate complexing nature of the Schiff base through phenolic oxygen and azomethine nitrogen atoms. The Schiff base ligand and Bismuth (III) complexes were assessed for antimicrobial activity. Assessment of antimicrobial activity against Gram-negative &amp; Gram-positive bacteria and fungi has demonstrated that the complex (III) was more active than the Schiff base.

Bismuth and Chlorine Dual-Doped Perovskite Chloride as a Phase-Structure-Stable and Moisture-Resistant Solid Electrolyte for Chloride Ion Batteries.

Perovskite chloride, an anion conductor, is a promising candidate to be a solid electrolyte for high-energy and sustainable chloride ion batteries (CIB). However, it suffers from poor structural stability at low temperature and in ambient conditions, which leads to its transformation from an ionic conductor to an insulator. Herein, a bismuth and chlorine dual doping strategy is developed to stabilize the cubic structure of CsSnCl3 in harsh environments. The as-prepared dual-doped CsSn0.9 Bi0.1 Cl3.1 material with an optimized composition maintains its cubic structure at the extremely low temperature of 213K for 10 days and at 40% relative humidity for 50 days, while the undoped cubic material deteriorates and transforms to a monoclinic phase under these conditions in less than 1 day. Consequently, the dual doping achieves efficient chloride ion conduction that is superior to single bismuth doping due to the introduction of interstitial chlorine facilitating chloride ion transport. Importantly, the practicality of the as-prepared solid electrolyte is demonstrated in different symmetric solid cells and by various CIBs using the organic electrode couple, a multivalent metal chloride cathode, or a new high-voltage metal oxychloride cathode.

Coal Fire Sublimates: Are We Missing Something?

Uncontrolled coal fires present a nearly unparalleled environmental and human health disaster. These fires can cause the destruction of the ecosystem, ignite forest fires, become a source of windblown dust and siltation of streams, and pollute surface water, ground water, and crops. They can cause significant disruption of families and communities resulting from physical hazards of collapse or explosion, excessive heat, visual blight and loss of potentially valuable acreage, deterioration of cultural infrastructure, personal and public property, and loss of a valuable energy resource. The emission of CO2 and other greenhouse gases presents a significant health hazard due to respiration of dust and aerosols, and exposure to acidic gases, potentially toxic trace elements, and organic compounds. Numerous studies have described many dozens of phases that have condensed from the effluents of these fires. However, many of these studies may have overlooked the nano- and ultra-fine particles that exist beside, in, and under the brightly colored, often spectacular crystalline macro phases. Using a scanning electron microscope with an energy dispersive X-ray detector we examined a small (30 mm × 10 mm) piece of condensate from an uncontrolled coal fire in the Jharia region of India and found more than 30 different phases in this one small piece. The phases included ammonium, copper, iron, lead, bismuth chlorides; bismuth, lead, and ammonium silici-fluorides; ammonium and lead iodates; iron, barium, lead, copper, and zinc sulfides; iron and silicon oxides; and others. Broken fragments revealed multiple generations of phases. Though not strictly nanoparticles (smaller than 0.1 μm), many of these particles are in the micrometer to sub-micron range and it is likely that there are phases present in the nanoparticle size range. Certainly, particulates in the nanoparticle and ultra-fine particle range are being released from the uncontrolled coal fires and may be impacting the environment and the health of the mine workers and nearby residents, an issue that should be investigated.

Advances in the improvement of photocatalytic activity of BiOCl nanomaterials under visible light

Abstract Photocatalysis is an effective way to alleviate the energy crisis and environmental pollution. Bismuth Chloride Oxide (BiOCl) is one of the most widely studied metal oxides due to its unique surface and electronic structure. However, the wide band gap of BiOCl and the high complexation rate of photogenerated electron–hole pairs limit its photocatalytic efficiency. Increasingly, efforts are being made to improve the performance of this range of photocatalysts. The article reviews the progress of research to enhance the photocatalytic activity of BiOCl nanomaterials. Strategies to improve the photocatalytic performance of single-phase BiOCl include morphological control, component adjustment, crystal facet control, and defects construction. Strategies to improve the photocatalytic activity of BiOCl-based composites include surface modification, immobilization of photocatalysts, impurity doping, and the construction of heterojunctions. In addition, the challenges and trends of BiOCl photocatalysts are discussed and summarized. Hopefully, this review will be helpful for the research and application of BiOCl photocatalysts.

Highly efficiency blue emissive from Bi3+ ions in zero-dimensional organic bismuth halide for white LED applications

Zero-dimensional organic-inorganic metal halides (OMHs) attract increasing interest in the fabrication of light-emitting diodes because of their broad emission band and high photoluminescence quantum yield. Thus, almost all OMHs showed green and yellow emissions, while blue was rarely reported. The luminescence mechanism of OMHs was attributed to the self-trapped excitons (STEs), no matter the similar performances between STEs and translations from energy levels of ns2 ions (Sb3+, Bi3+, and Te4+ ions). In this work, zero-dimensional organic tetraphenylphosphonium bismuth chloride TPP2BiCl5 (C48H40P2BiCl5, abbreviated as TBC, TPP=tetraphenylphosphonium.) was synthesized via the antisolvent method The obtained TBC showed the highest efficiency (58%) in blue light emission at 480 nm. While most of the OMHs function according to the STE mechanism, the emission of TBC was confirmed to originate from the 3P1-1S0 transition of Bi3+ ions. The white light-emitting diodes (WLEDs) with a color rendering index of 81 were fabricated by using a near-ultraviolet (NUV) chip, blue emitting single crystal TBC, green-emitting single crystal TPP2MnCl4 (C48H40P2MnCl4, abbreviated as TMC), and red-emitting single crystal TPP2SbCl5 (C48H40P2SbCl5, abbreviated as TSC). Moreover, the single-component white emission was achieved by doping Mn2+ and Sb3+ ions into the lattice of TBC. This work demonstrates the different emission mechanism of ns2 ions based OMHs, and the great potential of bismuth-based OMHs in the applications of WLEDs.

BiOCl Nanosheets with (001), (002), and (003) Dominant Crystal Faces with Excellent Light-Degradation Ability.

Gray bismuth chloride nanosheets with a highly enhanced electric field intensity were prepared by a simple and efficient method. Their energy gap is reduced to 2.35 eV. The prepared nanosheets show high photocatalytic activity for the degradation of rhodamine B under visible light. The resulting samples were characterized by X-ray diffractometry, high-resolution scanning electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, UV-vis diffuse reflectance spectroscopy, specific surface area analysis, electrochemical analysis, electron paramagnetic resonance, and UV-vis spectroscopy. The photocatalytic activity of prepared BiOCl was evaluated by the degradation of RhB. The prepared BiOCl sample (0.5 g/L) could completely degrade RhB (10 mg/L) within 10 min, and its visible photocatalytic activity was 80 times that of the original white BiOCl. Superoxide radicals were the main active substance involved in organic degradation.

Surfactant-Assisted Synthesis of Bismuth Oxychloride Nanoflowers for Electrochemical Sensing of Heavy Metal Ions

Heavy metal ion contamination of drinking water is a significant, invisible threat to public health which requires active and decentralized monitoring with high sensitivity, accuracy and reliability. The government and regulatory agencies actively survey and maintain established limits on heavy metal contamination, but generally prioritizing localized hotspots in high-risk communities. Their characterization techniques are typically expensive and inaccessible to the public, requiring specialized training and extended sample shipping times, with a purview restricted to public infrastructure. As plumbing systems corrode and contaminants leach into drinking water systems, independent means of oversight are becoming increasingly vital in effectively identifying and mitigating toxic exposure. In this work we propose the development and application of a high surface area bismuth oxychloride nanoflower for the electrochemical detection of zinc and lead ions in drinking water. The flower structure was synthesized via hydrolysis of bismuth chloride salt in a micellar environment of sodium dodecyl sulfate, followed by aqueous chemical reduction and transformation to metallic bismuth. The size and uniformity of the synthesized nanoflower was characterized with scanning electron microscopy (SEM), and the composition and microstructure were investigated using energy dispersive x-ray spectroscopy (EDS) analysis and x-ray diffraction (XRD). The nanoflowers were deposited onto a glassy carbon electrode and coated with a protective Nafion layer, prior to cyclic voltammetry analysis of analyte ion reactivity, achieving detection of lead and zinc ions in buffer and practical drinking water samples. These results indicate the viability of bismuth-based nanoflower structures for portable, accessible detection of heavy metal ions, with enhanced sensitivity.

Ultrathin mesoporous BiOCl nanosheets-mediated liposomes for photoelectrochemical immunoassay with in-situ signal amplification

Designing new biochemical sensors and achieving selectivity and high-sensitivity analysis is one of main research directions for immunoassays. Herein, a liposome-amplification photoelectrochemical (PEC) immunoassay was developed using ultrathin mesoporous bismuth chloride oxide nanosheets (BiOCl MSCN) for the highly selective and sensitive detection of carcinoembryonic antigen (CEA). Based on good photocurrent response of BiOCl MSCN toward dopamine, a liposome-conjugated secondary antibody loaded with dopamine was added for specific recognition in the presence of CEA. After the lysis treatment, the liberated dopamine was injected into the three-electrode electrolytic cell to enhance the photocurrent of BiOCl MSCN. Under the optimized conditions, the constructed liposome-mediated PEC immunoassay showed high sensitivity against CEA, with a dynamic response in the linear range of 0.05 ng mL−1 to 100 ng mL−1 and a detection limit of 35 pg mL−1. The present study proposes a new approach to the liposome-mediated PEC immunoassay constructed on ultrathin mesoporous BiOCl nanosheets, which can be used to target further the study of the sensing mechanism.

Integrating surface corrosion and imprinting strategy into PEDOT/Bi12O17Cl2 heterojunction embedded membrane aims to high permeability and selectivity

Development of photocatalytic membrane with antifouling, permeability, selectivity and reusability is highly desired for water treatment. Herein, an imprinted poly-3,4-ethylenedioxythiophene/oxygen-rich bismuth chloride oxide heterojunction embedded membrane (I-PEDOT/Bi12O17Cl2−M) with good self-cleaning and recyclability was fabricated by integrating surface corrosion and imprinting strategy. The introduction of imprinting technology endowed Z-type heterojunction (composed of Bi12O17Cl2 nanosheets and PEDOT) with imprinted cavities which possessed good selective adsorption ability for target pollutant (tetracycline, TC). Compared with pure nanosheets (Bi12O17Cl2) and non-imprinted nanosheets photocatalyst (NI-PEDOT/Bi12O17Cl2), the selectivity coefficient of I-PEDOT/Bi12O17Cl2−M were 3.35 and 2.01, respectively. Importantly, the corrosive solvent (NMP) changed the surface pore structure of polyvinylidene fluoride (PVDF), which firmly stuck the two-dimensional I-PEDOT/Bi12O17Cl2 in the surface pore of PVDF base membrane, avoiding the catalyst encapsulation issue of conventional methods and fully exposing the active sites. Therefore, I-PEDOT/Bi12O17Cl2−M exhibited good catalytic activity and stability. Particularly, the pure water flux and TC flux reached 4620 L/m2·h and 3580 L/m2·h, respectively. This study provides a new strategy for reasonable design of photocatalytic membrane with high permeability and good selectivity.

Bismuth trichloride as a molecular precursor for silicon doping

Dopant impurity species can be incorporated into the silicon (001) surface via the adsorption and dissociation of simple precursor molecules. Examples include phosphine (PH3), arsine (AsH3), and diborane (B2H6) for the incorporation of phosphorus, arsenic, and boron, respectively. Through exploitation of precursor surface chemistry, the spatial locations of these incorporated dopants can be controlled at the atomic scale via the patterning of a hydrogen lithographic resist layer using scanning tunneling microscopy (STM). There is strong interest in the spatial control of bismuth atoms incorporated into silicon for quantum technological applications; however, there is currently no known precursor for the incorporation of bismuth that is compatible with this STM-based lithographic method. Here, we explore the precursor chemistry (adsorption, diffusion, and dissociation) of bismuth trichloride (BiCl3) on Si(001). We show atomic-resolution STM images of BiCl3 exposed Si(001) surfaces at low coverage and combine this with density functional theory calculations to produce a model of the surface processes and the observed features. Our results show that, at room temperature, BiCl3 completely dissociates to produce bismuth ad-atoms, ad-dimers, and surface-bound chlorine, and we explain how BiCl3 is a strong candidate for a bismuth precursor compound compatible with lithographic patterning at the sub-nanometer scale.

Ni-foam based heterogenous Bi2S3 polyhedrons/multi walled carbon nanotubes (Bi2S3@MWCNTs/NF) as an advanced battery type electrode for enhanced supercapacitor performance

In current study, we report the hydrothermal synthesis of highly electroactive bismuth trichloride (Bi2S3) polyhedrons, modified with multi walled carbon nanotubes (MWCNTs). The physiochemical characterizations of pure Bi2S3 and Bi2S3@MWCNTs composite were carried out through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). XRD data revealed orthorhombic crystal structure of Bi2S3 having crystallite size of ∼13.23 nm, that got reduced to ∼10.81 for Bi2S3@MWCNTs composite. Polyhedral Bi2S3 showed some tendency to aggregate after fabricating with MWCNTs. Functional group analysis confirmed the formation of Bi–S bonds through multiple metal-sulfide bonding vibrations in the finger print region (880–550 cm−1). For electrochemical tests, Bi2S3/NF and Bi2S3@MWCNTs/NF were applied as electrodes. Due to the synergistic effects from highly conductive MWCNTs and pseudo-active Bi2S3, as prepared Bi2S3@MWCNTs/NF exhibited a significant enhancement in electrochemical response. The specific capacity of Bi2S3@MWCNTs/NF was measured as 625.1 C g−1, that was ∼1.45 times greater than that of non-fabricated Bi2S3 polyhedrons. Additionally, Bi2S3@MWCNTs/NF delivered a better charge/discharge efficiency. The values of RES (2.25 Ω) and RCT (3.54 Ω) prominently decreased for Bi2S3@MWCNTs/NF due to low internal and diffusional resistance.

СЕРЕБРЯНАЯ МИНЕРАЛИЗАЦИЯ В ГЛУБИННЫХ МАГМАТОГЕННЫХ СИСТЕМАХ ДРЕВНИХ ОСТРОВНЫХ ДУГ: ИЛЬДЕУССКИЙ УЛЬТРАОСНОВНОЙ МАССИВ, СТАНОВОЙ МОБИЛЬНЫЙ ПОЯС (ДАЛЬНИЙ ВОСТОК РОССИИ)

The Triassic (232–233 Ma) Ildeus mafic-ultrabasic massif is a fragment of a large mineralized magmatogenic system formed within the Stanovoy mobile belt at the Mesozoic stage of its evolution. Ultrabasic rocks are represented by cumulative plagioclase- and amphibole-bearing dunites, peridotites, websterites, and pyroxenites; basic rocks are gabbro-anorthosites, norites, and two-pyroxene gabbro. Most intrusive rocks of the Ildeus magmatogenic system experienced ultramafic (serpentine, chlorite, talc, carbonates) and acidic (quartz, biotite, potassium feldspar, secondary micas) metasomatism. Geochemical characteristics (calc-alkaline differentiation trend, negative anomalies of highly charged incoherent elements) indicate the subduction nature of the primary magma in the Ildeus system. The ultrabasic rocks are intruded by intermediate-acid intrusions with geochemical characteristics of adakite. Magmatic-stage silver mineralization is represented by microinclusions of cuprous silver, alloys of silver, copper, gold and zinc, acanthite and silver halides in association with pentlandite, chalcopyrite, bornite, and pyrrhotite. These rocks are characterized by microinclusions of native platinum, gold, tungsten, bismuth, lead, PGE alloys, W-Co-Ti, Sb-Pb, Cu-Zn-Sn, minerals of Ag-Cu-Sb-Se-S and Zn-Ni systems -Co-Fe-S, barite, chlorapatite and Bi-Sn-Pb chlorides. At the metasomatic stage, native silver, Au-Ag alloys, silver and copper chlorides, acanthite, silver and lead tellurides coexist with digenite, heathlewoodite, pyrite, sphalerite, galena, native nickel and gold, Cu-Zn alloys, sulfides of the Pb-As- Cu-Fe-S and bismuth chloride. At the magmatic stage, silver minerals crystallized under reducing conditions in the presence of high-temperature aqueous fluids enriched in sulfide sulfur, halogens, and volatile siderophile (W, Pt) and chalcophile (Ag, Bi, Sn, Sb, Pb) metals that entered the primary melt from serpentinites, metamorphosed gabbroids, and metal-bearing pelagic sediments of the subducting oceanic plate. Metasomatic parageneses of silver minerals were formed under oxidized near-surface conditions with the participation of low-temperature water-salt solutions with elevated concentrations of sulfate sulfur, arsenic, and tellurium. A two-stage model is proposed for the formation of silver mineralization in island arc magmatic systems, in which the high-temperature magmatic stage of formation in deep crustal parts is replaced by low-temperature hydrothermal ore formation processes in near-surface conditions.

BiCl3-catalyzed green synthesis of 4-hydroxy-2-quinolone analogues under microwave irradiation.

Traditional chemical synthesis, which involves the use of dangerous protocols, hazardous solvents, and toxic products and catalysts, is considered environmentally inappropriate and harmful to human health. Bearing in mind its numerous drawbacks, it has become crucial to substitute conventional chemistry with green chemistry which is safer, more ecofriendly and more effective in terms of time and selectivity. Elaborating synthetic protocols producing interesting new compounds using both microwave heating and heterogeneous non-toxic catalysts is acknowledged as a green approach that avoids many classical chemistry-related problems. In the current study, β-enaminones were used as precursors to the synthesis of modified 4-hydroxy-2-quinolone analogues. The synthesis was monitored in a benign way under microwave irradiation and was catalyzed by bismuth chloride III in an amount of 20 mol%. This method is privileged by using a non-corrosive, non-toxic, low-cost and available bismuth Lewis acid catalyst that has made it more respectful to the demands of green chemistry. The synthesized compounds were obtained in moderate to good yields (51-71%) and were characterized by 1H, 13C NMR, and IR spectroscopy as well as elemental analysis. Compound 5i was subjected to a complete structural elucidation using the X-ray diffraction method, and the results show the obtention of the enolic tautomeric form.