Transition Metal Chemistry最新文献

Photocatalytic hydrogen production powered by solar energy is a foundational technology for a sustainable hydrogen economy. Lead-free metal halide perovskites (MHPs) are at the forefront of this field, lauded for their superb optoelectronic properties and environmental compatibility. However, realizing their full potential requires overcoming the significant stability and performance challenges that have hindered widespread adoption. This article provides a critical and updated assessment of the remarkable progress in lead-free MHP development, with a specific focus on compositions centered around tin (Sn), bismuth (Bi), antimony (Sb), and copper (Cu), as well as advanced double perovskite structures. We explore the core principles of material design, from crystal and electronic band structure engineering to innovative strategies for enhancing stability in aqueous environments, such as heterostructuring, dimensionality control, and surface passivation. The analysis includes a review of performance benchmarks, including hydrogen evolution rates now exceeding 1700 μmol g⁻¹ h⁻¹ (among the highest reported for tin-based systems and competitive with some lead-based analogues), and the optimization techniques that enable such achievements. Despite these advances, formidable challenges remain in achieving long-term operational stability and closing the efficiency gap with both lead-based counterparts and the targets for economic viability, which project a need for green hydrogen costs below $2/kg. We conclude by outlining the key future research frontiers essential for propelling these eco-friendly photocatalysts toward large-scale solar fuel generation. These frontiers include the urgent need for standardized testing protocols, a deeper mechanistic understanding through operando studies, and the integration of machine learning for accelerated materials discovery and inverse design, all of which are imperative for translating laboratory breakthroughs into practical, impactful technologies.

Determining stability constants provides insight into metal-ligand affinity and complex stability, essential for understanding selectivity and potential applications. In this regard, we measured the stability constants of first row transition metal ions with macrocyclic tetrathioethers. namely, 1,4,7, 10-tetrathiocyclododecane ([12]aneS₄), 1,4,8,11-tetrathiocyclotetradecane ([14]aneS₄) and 1,5,9,13-tetrathiocyclohexadecane ([16]aneS₄). All three ligands have the same number of sulfur atoms but different number of atoms making the overall structure and the size of the cavity of the ligand increase from [12]aneS₄ to [16]aneS₄. The metal ions selected for the study were chromium, manganese, iron, cobalt and nickel. The stability constants of the complexes that showed observable complex formation in solutions were measured using the McConnell-Davidson method. Out of the metal ions studied, only nickel and cobalt show observable complex formation. Although nickel forms measurable complexes with all three macrocyclic ligands, cobalt forms a complex only with [14]aneS₄. Chromium, manganese and iron do not show any complex formation with the macrocyclic tetrathioethers investigated in this study. The stability constants determined are as follows: Ni^II([12]aneS₄) (4.0 M^-1), Ni^II([14]aneS₄) (75.0 M^-1), Ni^II([16]aneS₄) (166.0 M^-1) and Co^II([14]aneS₄) (133.0 M^-1). The nickel complexes show a slight increase in stability constants going from [12]aneS₄ to [16]aneS₄. The stability constant of Co^II( [14]aneS₄) (133.0 M^-1) exceeds that of Ni^II([14]aneS₄) (75.0. M^-1). To the best of our knowledge, this is the first report of determination of apparent stability constants for Ni^II([12]aneS₄), Ni^II([16]aneS₄) and Co^II([14]aneS₄). Job’s plots indicate that both metal ions, cobalt and nickel form 1:1 metal to ligand complexes with all three macrocyclic tetrathioethers in solution. The stability constants obtained in the present study are compared with reported stability constants of copper complexes with the same macrocyclic tetrathioethers.

The development of metal-based drugs capable of releasing NO in a controlled manner is of great interest due to their biological responses, including anticancer activities. To this end, the compounds cis-[Ru(NO)Cl(cyclen)]X₂ (X = Cl⁻ or ClO₄⁻) and cis-[RuCl₂(cyclen)]Cl were synthesized using efficient ultrasound-assisted methods. The nitrosyl complex was fully characterized by FTIR, UV-Vis spectroscopy, NMR, and single crystal XRD. Its reactivity was investigated through electrochemical and photochemical studies. The complex was found to release NO upon photolysis at 365 nm, with an apparent quantum yield of 0.204 mol/Einstein. The kinetics of ligand release upon reduction revealed a two-step process: a rapid chloride release (k₁ = 10.1 s^− 1) followed by a much slower NO release (k₂ = 3.0 × 10^− 4 s^− 1 at 25 °C). Electrochemical investigations supported a mechanism involving the formation of the aqua-nitrosyl intermediate, cis-[Ru(NO)(H₂O)(cyclen)]²⁺, and elucidated the parallel pathways leading to the final Ru(II)-aqua species. These experiments enhance our understanding of the nitrosyl complex reactivity towards reduction and photochemical processes, highlighting its potential as a controlled NO-releasing metallodrug.

A new polymeric copper(II)–maleato complex, used as a dicarboxylate ligand, was synthesized {Na₂[Cu(C₄H₂O₄)₂]·2H₂O}_n (1). The resulting complex was characterized by elemental analysis, infrared and UV–visible spectroscopy, and X-ray crystallography. Spectroscopic data indicate that the maleato ion coordinates in a chelating bidentate mode, creating a distorted square planar coordination environment around Cu(II). X-ray crystallography confirmed the formulation (1) and revealed that the central Cu(II) ion is in a distorted square planar. The maleato ion acts as a bidentate chelator, coordinating through two carboxylate oxygens to form a stable four-membered ring. This study extends our understanding of the coordination behavior of π-conjugated dicarboxylic acids with transition-metal ions. Molecular docking studies demonstrated that the polymeric copper(II)–maleic acid complex exhibited strong binding affinity toward B-DNA (1BNA), with a binding energy of – 10.2 kcal/mol and multiple stable hydrogen bond interactions. The molecular docking results demonstrated that the polymeric copper(II) complex with maleic acid forms conventional hydrogen bonds with B-DNA. Specifically, interactions were observed with guanine and cytosine bases: the O2 atom of cytosine (DC21), the O4′ atom of guanine (DG24), and the hydrogen atoms of guanine residues DG2, DG4, and DG22. The hydrogen bond distances (2.10–2.89 Å) confirm the stability of these interactions. Moreover, several of these interactions are located within or near the minor groove of DNA, indicating a groove-binding mode. In addition, the complex exhibits an intramolecular hydrogen bond that stabilizes its conformation during binding.

The global energy sector remains among the largest human-driven contributor to CO₂ emissions, making its transformation imperative in the fight against climate change. Transitioning to clean, renewable energy sources is not just an option but a necessity for a sustainable future. In this context, Algeria’s exceptional solar potential presents a unique opportunity to maximize the efficiency of solar energy systems and accelerate the transition toward green solutions. In this respect, heterogeneous photocatalysis stands out as one of the most cost-effective methods for harnessing renewable energy and mitigating pollution. This study explores the potential of photocatalytic Hydrogen Evolution Reaction (HER), a game-changing clean energy solution that aligns with global decarbonization goals. Through light-driven water splitting, renewable hydrogen can be generated efficiently, providing a viable path to reduce greenhouse gas emissions. Despite considerable efforts in the field of Nano-composite, a major challenge remains: achieving high efficiency and selectivity in sunlight-driven HER. Hydrogen, with its high energy density and zero-carbon footprint, represents a pillar of the clean energy transition. This study provides key information for strategic investments in Algeria, identifying prime locations (with sunshine above 100 mW cm^− 2) for hydrogen production where solar energy can be harnessed at an unprecedented scale.

Two three-dimensional (3D) Cd-based metal-organic frameworks (MOFs), [Cd(L1)(L2)]·(CH₄O)₁₆ (Cd-1) and [Cd(L1)(L3)]·(C₃H₇NO)_1.5(CH₄O)₅ (Cd-2), have been rationally designed and synthesized by using 10,10’-bis((E)-2-(pyridin-4-yl)vinyl)-9,9’-bianthracene (L1), 1,4-benzenedicarboxylic acid (H₂L2) or 4,4’-biphenyldicarboxylic acid co-ligand (H₂L3) and CdCl₂·4H₂O under solvothermal conditions. The structures have been determined by single-crystal X-ray diffraction analyses and further characterized by IR spectra, UV-Vis spectra, and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction analyses reveal that Cd-1 consists of a 3D network with one-dimensional (1D) channels, while Cd-2 with longer dicarboxylate ligands consists of a 3D network with interpenetration of two infinite structures. Moreover, the two MOFs exhibit strong luminescent emission in solid state at room temperature. The stability of Cd-1 and Cd-2 at different temperatures was analyzed by thermogravimetry.

The mixed-ligand complexes cis-[(MoO)₂O(glyc)₂(phen)₂]·5H₂O (1) and trans-[(MoO)₂O(glyc)₂(phen)₂] (1-5H₂O) were synthesized under hydrothermal conditions. Cis-structure complex 1 exhibits reversible transformation to trans-structure complex 1-5H₂O. Structural analysis reveals that the crystal structure of 1 contains 2D water cluster layers featuring twelve-membered rings. EPR spectroscopic studies demonstrate that the two molybdenum atoms in both 1 and 1-5H₂O exist as independent paramagnetic centers. Furthermore, solid state ¹³C NMR spectra of 1 and 1-5H₂O reveal large downfield shifts for the coordinated glycolate moieties. Notably, the catalytic performance of 1 in the degradation of methyl orange is significantly superior to that of 1-5H₂O, which could be attributed to the steric hindrance difference induced by cis-trans isomerism.

The rising demand for scandium (Sc) in aerospace, fuel cells, and electronics requires sustainable extraction technologies. This study investigates scandium recovery from Indonesian limonitic laterite ore using atmospheric pressure acid leaching (APAL) with sulfuric acid (H₂SO₄) and acetic acid (CH₃COOH) as lixiviants. Leaching temperature (30–90 °C) and pH (ranging from − 1.2 to 1.24 for H₂SO₄; 2.13 to 2.87 for CH₃COOH) were varied to evaluate their influence on extraction efficiency. Response Surface Methodology (RSM) was applied to model process performance and identify optimal conditions. Results showed that lower pH (i.e., more acidic conditions) and higher temperatures significantly enhanced scandium recovery. Sulfuric acid achieved a maximum recovery of 92.94% at 90 °C and pH − 1.2, while acetic acid reached 56.47% at 90 °C and pH 2.13. XRF analysis confirmed scandium content of 79 ppm in the ore, indicating its potential as a feedstock for critical metal extraction. Compared to high-pressure acid leaching, the APAL approach offers a lower-energy, safer, and cost-effective alternative, especially in decentralized or infrastructure-limited regions. The use of acetic acid also presents a more environmentally friendly option. This study advances sustainable hydrometallurgical practices for scandium recovery from lateritic ores.

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Tungsten trioxide-(WO₃) is one of the utmost appropriate inorganic electrochromic materials. WO₃ nanostructures are becoming increasingly prevalent in a diverse array of electrochromic (EC) device applications, as it offers substantially larger active response area, which leads to an increase in colour contrast, according to research. The novel technique of powder synthesis and material preparation has gained interest as materials science advances. Recently, the hydrothermal approach has emerged as a viable liquid phase preparation methodology as it provides several benefits. In this view it becomes essential to deepen the understanding of hydrothermal synthesis towards carving WO₃ nanostructures to foster electrochromic state-of-the-art. In this review analysis of hydrothermal synthesis towards sculpturing various WO₃ nanostructures such as nanowire, nanotubes, nanoflower, Nano tree etc. for modest electrochromism has been portrayed. Moreover, practicality in role of various hydrothermally synthesized WO₃ nanostructures for different applications has also been discussed.

Aminocarbonylation reactions represent a powerful synthetic strategy for constructing amide bonds—key structural motifs in pharmaceuticals, agrochemicals, and functional materials. In recent years, magnetic nanocatalysts have gained significant attention as efficient, sustainable, and reusable platforms for promoting these transformations. This review highlights recent developments in the design, application, and mechanistic understanding of magnetic nanocatalysts employed in aminocarbonylation reactions. Emphasis is placed on systems based on palladium, nickel, and copper nanoparticles supported on magnetically responsive materials such as Fe₃O₄, which enable facile catalyst separation and reuse via external magnetic fields. The role of surface functionalization, core–shell architectures, and ligand modification in enhancing catalytic performance is discussed in detail. In addition, we address key challenges, including metal leaching, deactivation, and scalability, and explore the growing interest in carbon monoxide surrogates for safer, greener aminocarbonylation. Outlooks on the integration of magnetic nanocatalysts with continuous-flow technologies and the potential of machine learning in catalyst design are also presented. Overall, this review underscores the significant potential of magnetic nanocatalysts in developing efficient, scalable, and environmentally responsible aminocarbonylation protocols for modern synthetic chemistry.

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