Search Results (78)

Phosphate pollution caused by human activities has become a pressing environmental issue, leading to eutrophication and severe ecological risks. In this study, artificial humic acid (HA) and fulvic acid (FA) were synthesized from tung fruit and glucose, respectively, and further composited with ferrihydrite (Fh) to prepare HA/Fh and FA/Fh adsorbents for phosphate removal. The structural and morphological characteristics of the composites were confirmed by SEM, XRD, FTIR, and XPS analyses, which indicated successful complexation of HA or FA with Fh through ligand exchange and surface interactions. Batch adsorption experiments revealed that HA/Fh and FA/Fh exhibited significantly enhanced adsorption capacities compared to pristine Fh, with maximum Langmuir adsorption capacities of 33.67 mg g⁻¹ and 37.06 mg g⁻¹, respectively. The adsorption behavior was well described by the pseudo-second-order kinetic model and the Langmuir isotherm, suggesting a chemisorption-dominated process involving ligand exchange between surface –OH groups of Fh and phosphate ions, supplemented by electrostatic attraction. Coexisting ion studies demonstrated that Cl⁻ and SO₄²⁻ slightly promoted phosphate adsorption, while NO₃⁻ and CO₃²⁻ strongly inhibited it, highlighting the competition of multivalent anions with phosphate for Fe³⁺ active sites. Importantly, the phosphate-enriched adsorbents can be directly recycled as phosphorus fertilizers, providing a sustainable pathway for both environmental remediation and phosphorus resource recovery. Full article

Traditional Fe-based materials are limited for Cr(VI) remediation due to low reactivity, oxidation, and aggregation. Although chitosan coatings improve stability, they hinder efficient liquid-solid separation. To overcome this, a novel phosphorus-modified magnetic chitosan adsorbent (PCC/Fe₃O₄) was synthesized using Fe₃O₄ as the core and tetrakis hydroxymethyl phosphonium sulfate (THPS) as a cross-linking agent. The composite exhibited a high surface area (20.67 m²/g) and superparamagnetism, enabling easy magnetic recovery. PCC/Fe₃O₄ demonstrated superior Cr(VI) removal capabilities compared to unmodified chitosan and raw Fe₃O₄, achieving a saturated adsorption capacity of 23.6 mg/g under the selected conditions (pH 6, initial Cr(VI) concentration of 1 mg/L), which were chosen to balance adsorption efficiency, adsorbent stability, and environmental relevance. The main removal mechanism includes electrostatic attraction, redox reaction, and ligand exchange. PCC/Fe₃O₄ maintained 86% efficiency after 5 d aging and >90% efficiency after five cycles, demonstrating excellent stability and reusability and strong potential for practical environmental remediation. Full article

The eutrophication of natural water is a severe environmental risk faced by coastal marine ecosystems, and the excess nitrogen and phosphorus in aquaculture effluent are one of the main sources of environmental pollution. Effectively reducing as well as controlling the phosphorus content in aquaculture effluent is of great importance for alleviating eutrophication and the governance of coastal environments. This study focuses on addressing phosphorus pollution by developing novel bimetallic Ce-Al-MOFs adsorbents via the microwave-assisted rapid synthesis method, among which the monomer Ce₃Al₃-BDC₃ exhibits excellent phosphate adsorption capacity (136.99 mg P g⁻¹) and great removal efficiency over a wide pH range (2~10). Batch experiments reveal that the adsorption is followed by pseudo-second-order kinetics and the Langmuir isotherm model, indicating monolayer chemisorption. The MOFs material shows high selectivity for phosphorus even under the interference of co-existing anions, as well as excellent reusability, retaining over 65% removal efficiency after six adsorption–desorption cycles. Field tests in coastal areas and indoor aquaculture systems both achieve over 97% phosphate removal, meeting discharge standards. A series of characterization methods identify ligand exchange, electrostatic interactions and surface complexation as key adsorption mechanisms. The Ce-Al-MOFs present a promising solution for mitigating eutrophication and managing aquaculture wastewater sustainably. Full article

Phosphorus (P) is essential to life yet constrained by finite reserves, heterogeneous distribution, and strong chemical binding to soil minerals. Pedogenesis progressively alters the availability of P: in ‘young’ soils, P associated with Ca and Mg is relatively labile, while in ‘old’ soils, acidification and leaching deplete base cations, shifting P into organic matter and recalcitrant Al- and Fe-bound pools. Podzolized soils (Spodosols) provide a unique lens for studying this transition because podzolization vertically segregates these dynamics into distinct horizons. Organic cycling dominates the surface horizon, while downward translocation of Al, Fe, and humus creates a spodic horizon that immobilizes P through sorption and co-precipitation in amorphous organometal complexes. This spatial separation establishes two contrasting P pools—biologically dynamic surface P and mineral-stabilized deep P—that may be variably accessible to plants and microbes depending on depth, chemistry, and hydrology. We synthesize mechanisms of spodic P retention and liberation, including redox oscillations, ligand exchange, root exudation, and physical disturbance, and contrast these with strictly mineral-driven or biologically dominated systems. We further propose that podzols serve as natural experimental models for ecosystem aging, allowing researchers to explore how P cycling reorganizes as soils develop, how vertical stratification structures biotic strategies for nutrient acquisition, and how deep legacy P pools may be remobilized under environmental change. By framing podzols as a spatial analogue of long-term weathering, this paper identifies them as critical systems for advancing our understanding of nutrient limitation, biogeochemical cycling, and sustainable management of P in diverse ecosystems. Full article

This work reports the synthesis and characterization of a novel rhenium(I) complex incorporating a phosphorus–nitrogen (P,N) ligand. The compound crystallizes in a distorted octahedral geometry, as confirmed by single-crystal X-ray diffraction analysis. The complexes were evaluated as catalysts in the transfer hydrogenation of acetophenone using 2-propanol as the hydrogen source. Comparative studies with other rhenium(I) complexes bearing polypyridine ligands revealed high catalytic performance, achieving conversions between 68% and 99%. These results highlight the promising potential of P,N-ligand rhenium complexes in homogeneous transfer hydrogenation catalysis. The optimal reaction time was found to be 4 h for the complexes studied, with only the fac-[Re(CO)₃(PN)Cl] complex showing improved conversion upon extending the reaction time to 7 h, likely due to the donor effects provided by the P,N-ligand. Full article

This article reviews recent advances in heterogeneous hydroformylation, with a particular focus on rhodium-based catalysts supported on oxide surfaces. The hydroformylation reaction is a vital industrial process for producing aldehydes from petrochemicals. This reaction involves the addition of carbon monoxide (CO) and hydrogen (H₂) to alkenes, resulting in the formation of aldehydes. Aldehydes serve as essential building blocks for various downstream products in the chemical industry, including alcohols, esters, and amines. Although homogeneous catalysts such as rhodium complexes coordinated with phosphorus-based ligands (e.g., [RhCl(PPh₃)₃]) are highly active and selective, their separation and recovery remain significant challenges. This has fueled growing interest in the development of heterogeneous catalysts, which offer advantages in terms of sustainability, reusability, and catalyst recovery. This review highlights recent progress in the design of heterogeneous hydroformylation catalysts, with emphasis on rhodium-based systems on oxide supports. Key challenges and emerging strategies for enhancing catalytic performance and stability are also discussed. Full article

A novel heterobimetallic ruthenium(II)–gold(I) complex featuring a bridging bis(diphenylphosphino)butane (dppb) ligand was prepared and fully characterized. Single-crystal X-ray diffraction revealed a piano-stool geometry around Ru(II) with η⁶-cymene, two chlorido ligands, and one phosphorus atom from dppb, while the Au(I) center adopts a linear P–Au–Cl coordination. Structural integrity in the solution was confirmed by 1D and 2D NMR spectroscopy, while solution behavior was further monitored by variable solvent ³¹P NMR and UV/Vis spectroscopy, indicating that the organometallic Ru–arene core remains intact, whereas the chlorido ligands coordinated to Ru exhibit partial lability. Complementary characterization included elemental analysis, FTIR, and UV/Vis spectroscopy. Spectrofluorimetric and FRET analyses showed that Au(dppb), Ru(dppb), and the heterobimetallic AuRu complex bind to BSA with apparent constants of 1.41 × 10⁵, 5.12 × 10², and 2.66 × 10⁴ M⁻¹, respectively, following a static quenching mechanism. In vivo biological evaluation in Wistar rats revealed no significant hepatotoxicity or nephrotoxicity, with only mild and reversible histological alterations and preserved hepatocyte nuclear morphology. Hematological analysis indicated a statistically significant reduction in leukocyte populations, suggesting immunomodulatory potential, while elevated serum glucose levels point to possible endocrine or metabolic activity. These findings highlight compound structural stability and intriguing bioactivity profile, making it a promising platform for further organometallic drug development and testing. Full article

Lanthanide rare earth elements possess significant promise for material applications owing to their distinctive optical and magnetic characteristics, as well as their versatile coordination capabilities. This study introduced a lanthanide-functionalized magnetic nanocellulose composite (NNC@Fe₃O₄@La(OH)₃) for effective phosphorus/nitrogen (P/N) ligand separation. The hybrid material employs the adaptable coordination geometry and strong affinity for oxygen of La³⁺ ions to show enhanced DNA-binding capacity via multi-site coordination with phosphate backbones and bases. This study utilized cellulose as a carrier, which was modified through carboxylation and amination processes employing deep eutectic solvents (DES) and polyethyleneimine. Magnetic nanoparticles and La(OH)₃ were subsequently incorporated into the cellulose via in situ growth. NNC@Fe₃O₄@La(OH)₃ showed a specific surface area of 36.2 m²·g⁻¹ and a magnetic saturation intensity of 37 emu/g, facilitating the formation of ligands with accessible La³⁺ active sites, hence creating mesoporous interfaces that allow for fast separation. NNC@Fe₃O₄@La(OH)₃ showed a significant affinity for DNA, with adsorption capacities reaching 243 mg/g, mostly due to the multistage coordination binding of La³⁺ to the phosphate groups and bases of DNA. Simultaneously, kinetic experiments indicated that the binding process adhered to a pseudo-secondary kinetic model, predominantly dependent on chemisorption. This study developed a unique rare-earth coordination-driven functional hybrid material, which is highly significant for constructing selective separation platforms for P/N-containing ligands. Full article

Background: The increasing prevalence of processed foods has significantly elevated dietary phosphorus intake globally, posing a risk to skeletal health. Elevated serum phosphate promotes parathyroid hormone (PTH) release, leading to bone resorption and decreased bone formation. Objective: This study investigated the influence of chronically elevated phosphorus intake on bone structure in rats with normal renal function, focusing on the Receptor Activator of Nuclear factor Kappa-B (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) pathway and its related components, leucine rich repeat containing G protein-coupled receptor 4 (LGR4), and R-spondins (RSPOs). Methods: Rats were fed a high-phosphorus diet, followed by assessment of the bone microstructure and of the expression of key signalling molecules. Results: Elevated phosphorus intake induced significant bone deterioration, particularly in the trabecular bone compartment, associated with alterations in the RANK/RANKL/OPG pathway and in the LGR4 and RSPO1 and RSPO4 signalling components in bone. Moreover, we also observed changes in RANKL, RSPO1 and RSPO4 serum levels in the rats that had received a high-phosphorus diet. Conclusions: These findings highlight the detrimental impact of excessive dietary phosphorus on skeletal health, even without renal impairment, and suggest that components of this pathway, particularly RSPO1 and RSPO4, could serve as potential biomarkers of bone deterioration. The widespread consumption of phosphorus-rich processed foods underscores the importance of nutritional education to mitigate these skeletal risks in industrialized populations. Full article

Organophosphorus compounds (OPC) are a large class of organic compounds that provide a wide range of applications, and their importance has grown steadily in recent years. In each category and family, these compounds have similarities and differences. Due to their immense variety, these chemicals have various properties and, therefore, various applications. In fact, various works have been published recently that present the main applications of OPC, especially in metal extraction. Despite their extemsive range of use, optimizing their performance as extractant agents remains a challenge due to their structural variability and sensitivity to process parameters. This review provides a critical analysis of pentavalent OPCs, focusing on how their chemical nature influences heavy metal extraction efficiency. For the first time, we present a novel classification system for OPCs based on phosphorus valency and heteroatom coordination, offering a framework to guide future research. Our findings reveal that the direct coordination of the phosphorus to heteroatoms such as oxygen, sulfur, and nitrogen has a great influence on the physicochemical characteristics of the extractant and the metal extraction efficiency. This observation is in line with Pearson’s Hard and Soft Acids and Bases (HSAB) theory in the sense that it demonstrates that altering the heteroatom alters the metal affinity of the ligand. As a result, these structural modifications can improve the extraction performance by up to 40% for some heavy metals, highlighting the potential for optimized molecular designs to maximize industrial applications. In the future, this work offers a solid foundation for future studies on the rational design of organophosphorus-based extractants. Using HSAB theory and our novel classification system, researchers can rationally design OPCs for their target metal with unparalleled precision. These results have transformative impacts on metal recovery efficiency-intensive sectors like mining, waste recycling, and clean energy technologies. Full article

Developing a new efficient separation ligand based on the “CHON” principle to address the limitations of phosphorus containing extractants in nuclear fuel reprocessing can help further simplify the process flow and reduce the amount of secondary waste. Building upon this critical need, a novel ligand was developed through a strategic application of the Hard and Soft Acids and Bases (HSAB) theory, integrating a soft donor nitrogen atom into the linear architecture of bis-diglycolamide. This groundbreaking ligand, named N,N′-bis[2-(2-(N,N-dioctylcarbamoyl)ethoxy)ethylacetamido]-N″-diethylenetriamine (TOMDEA-BisDGA), has demonstrated remarkable potential in the extraction of Pu(IV). The study unveils that the ligand demonstrates remarkable selectivity and separation efficiency towards Pu(IV) ions while maintaining an exceptionally low extraction capacity for U(VI) across a wide acidity spectrum of 0.1~6 mol/L. To explain the structure properties of complex formed by the ligand and Pu(IV), a systematic analysis was performed, including slope analysis, proton nuclear magnetic resonance (NMR) titration, and Fourier-transform infrared (FT-IR) spectroscopy. This study explores the coordination and separation behavior of diglycolamide ligands with actinide. This work is expected to provide important information and theoretical bases upon which advanced design and optimization of ligands for high-performance processes for the separation of plutonium might be carried out. Such findings will contribute to the understanding of actinide chemistry and further the design of improved separation methods for nuclear applications. Full article

Excessive phosphorus discharge from fertilizers and detergents has caused severe eutrophication in water bodies, necessitating the upgrading of efficient and cost-effective adsorbents for phosphorus removal. In this study, a novel lanthanum and extracellular polymeric substance (EPS) coprecipitation-modified ceramic (La-EPS-C-450) was developed to address the limitations of existing adsorbents. The ceramic filler served as a robust and scalable matrix for lanthanum loading, while EPS introduced functional groups and carbonate components that enhanced adsorption efficiency. The prepared adsorbent manifested a maximum phosphorus adsorption capacity of 83.5 mg P/g-La at 25 °C, with its performance well expressed by the Freundlich isotherm model, indicating that it was a multilayer adsorption process. The adsorption mechanism was driven by electrostatic attraction and ligand exchange between lanthanum and phosphate ions, forming inner-sphere complexes. The material demonstrated unfluctuating‌ performance across a pH range of 3–7 and retained high selectivity in the presence of competing anions. In practical applications, La-EPS-C-450 effectively removed phosphorus from actual river water, achieving a treatment capacity of 1800 bed volumes in a continuous-flow fixed column system. This work provides valuable insights into the progress of advanced ceramic-based adsorbents and demonstrates the potential of La-EPS-C-450 as a cost-efficient and effective material for phosphorus removal in water treatment applications. Full article

Azine compounds have recently gained significant attention due to the interesting properties that they display, which could be relevant in fields such as Pharmacology and Material Sciences. These types of ligands stand out in Coordination Chemistry because of the facilities that they exhibit that make it easy to coordinate transition and post-transition metal ions. Furthermore, to the azine skeleton (C=N-N=C), the addition of other donor atoms such as sulfur, oxygen or phosphorus in the ligand increases the coordination possibilities. In this sense, we are interested in azine ligands as precursors of novel metallosupramolecular architectures. The research herein reported is focused on the synthesis and characterization of a potentially tetradentate [P₂O₂] organic phosphine-azine ligand (LP). The addition of the phosphine group to the azine skeleton allows for the stabilization of soft metal ions and the assembly of functional structures. The azine ligand LP⁸ has been prepared by a condensation reaction between two equivalents of (diphenylphosphino)benzaldehyde and one equivalent of azine monohydrate, and it was fully characterized by using several techniques such as elemental analysis, mass spectrometry, infrared spectroscopy, ¹H NMR spectroscopy and X-ray diffraction. Full article

The chemistry of bidentate ligands with a dppf-like motif, where phosphorus is fully or partially replaced by other pnictogens as donor sites, is summarized and discussed in this comprehensive review, while covering the literature from 1966 to 2024, related to more than 165 original references and discussing more than 75 independent chemical entities (1–41). Besides addressing synthetic, structural, and electrochemical aspects of such compounds, their donor properties and metal coordination behavior is discussed, along with catalytic applications. Based on their electronic and steric situations, trends in the performance of such compounds, either as ligands for catalysis or on their own merits for non-catalytic purposes, have been elucidated. Related topics that could not be covered in this article have been acknowledged by referring to the literature for completeness. Full article

Phosphorus mainly exists in the form of phosphate in water. Excessive phosphorus can cause eutrophication, leading to algae reproduction and the depletion of oxygen in water, destroying aquatic ecology. This study prepared quaternized polyaniline (PN) and quaternized polyaniline with lanthanum hydrate (HLO-PN), and a new nanocomposite for removing phosphate from wastewater was proposed. The results of adsorption experiments show that HLO-PN can effectively remove phosphate in the range of pH 3~7; the maximum adsorption capacity is 92.57 mg/g, and it has excellent anti-interference ability against some common coexisting anions (${\mathrm{F}}^{-},$ ${\mathrm{C}\mathrm{l}}^{-},$ ${\mathrm{NO}}_3^{-},$ ${\mathrm{SO}}_4^{2-}$) other than ${\mathrm{CO}}_3^{2-}$. After five adsorption–desorption cycles, the phosphate adsorption capacity (60 mg/g) was still 74.28% of the initial adsorption capacity (80.85 mg/g), indicating that the HLO-PN nanocomposites had good reusability and recovery of phosphorus. The characterization results show that phosphate adsorption is realized by electrostatic adsorption and ligand exchange. Full article