Dalton Transactions最新文献

In the context of developing next-generation information technology, two-dimensional materials with inherent ferromagnetism, a Curie temperature above room temperature, and significant magnetic anisotropy hold great promise. In this work, we employed first-principles calculations to investigate a novel two-dimensional Janus structure, namely SVAN₂ (A = Si, Ge). Our findings reveal that these structures are not only dynamically and thermally stable, but also exhibit semiconductor properties alongside their ferromagnetic states. The Janus SVSiN₂ monolayer exhibits an in-plane easy axis, while the SVGeN₂ monolayer shows an out-of-plane easy axis, both characterized by a significant magnetic anisotropy energy (129 and 172 μeV, respectively). Notably, through Monte Carlo simulation, we found that the Curie temperature of the SVSiN₂ monolayer is 330 K, which is higher than room temperature. Finally, by applying biaxial strain and an external electric field, we successfully regulated the electronic properties of the SVAN₂ (A = Si, Ge) monolayers, enabling a transition from semiconductor to half-metallic behavior. These remarkable electronic and magnetic properties make the Janus SVAN₂ (A = Si, Ge) monolayers promising candidate materials for spin electron applications.

Correction for ‘Synthesis of novel solid scale inhibitors based on silver tungstate loaded KIT-6 for scale removal from produced water: static and modeling evaluation’ by Heba M. Salem, et al., Dalton Trans., 2023, https://doi.org/10.1039/d3dt02594b.

Advanced ionic conductors are crucial for a large variety of contemporary technologies spanning solid state ion batteries, fuel cells, gas sensors, water desalination, etc. In this work, we report on a new member of KTiOPO₄-structured materials, NaGaPO₄F, with sodium-ion conductivity. NaGaPO₄F has been obtained for the first time via a facile two-step synthesis consisting of a hydrothermal preparation of an ammonia-based precursor, NH₄GaPO₄F, followed by an ion exchange reaction with NaNO₃. Its crystal structure was precisely refined using a combination of synchrotron X-ray powder diffraction and electron diffraction tomography. The material is thermally stable upon 450 °C showing no significant structural transformations or degradation but only a ∼1% cell volume expansion. Na-ion mobility in NaGaPO₄F was investigated by a joint experimental and computational approach comprising solid-state nuclear magnetic resonance (NMR) and density functional theory (DFT). DFT and bond-valence site energy (BVSE) calculations reveal 3D diffusion of sodium in the [GaPO₄F] framework with migration barriers amounting to 0.22 and 0.44 eV, respectively, while NMR yields 0.3–0.5 eV that, being coupled with a calculated bandgap of ∼4.25 eV, makes NaGaPO₄F a promising fast Na-ion conductor.

Triazole polycarboxylic acid ligands are widely employed in the construction of MOFs due to their strong coordination ability and flexible coordination modes. In this work, three novel complexes (Pb(MCTCA)(H₂O) (1), Co(HMCTCA)₂(H₂O)₂ (2) and Cu(HMCTCA)₂(H₂O)₂ (3)) based on the H₂MCTCA ligand (5-methyl-1-(4-carboxyl)-1H-1,2,3-triazole-4-carboxylic acid) were successfully synthesized under hydrothermal conditions, respectively. X-ray single crystal structure analysis shows that complex 1 is a 3D network structure, where the central metal Pb(II) is six coordinated to form deformed triangular prism geometry. The complexes 2 and 3 are both 2D layer supramolecular structures connected through intermolecular hydrogen, where the central metals (Co/Cu) are six coordinated to form octahedral configuration geometry. Based on functional properties, it is found that complex 1 exhibits excellent detection ability for small-molecule drugs (azithromycin, colchicine and balsalazide disodium) and actinide cations (Th⁴⁺ and UO₂²⁺) within a lower concentration range without interference from other components. In particular, the detection limits of three small-molecule drugs are all lower than 0.30 μM. In addition, complexes 2 and 3 exhibited excellent catalytic reduction performance toward p-nitrophenol (PNP), with a reduction efficiency exceeding 98%. These experimental results evidence that complexes 1–3 have potential application prospects in fluorescence sensing and catalytic reduction.

A phosphor-converted light-emitting diode (pc-LED) is a prime light source in smart broadband near-infrared (NIR) spectroscopy. The performance of NIR pc-LEDs crucially depends on the employed NIR luminescent materials. In this study, we synthesized a novel high-efficiency broadband NIR phosphor, CaY₂Mg₂Ge₃O₁₂:Cr³⁺ (CYMG:Cr³⁺). Under 450 nm excitation, CYMG:Cr³⁺ exhibited remarkable broadband NIR emission from 650 to 900 nm with a full width at half maximum (FWHM) of 115 nm. Within the CYMG lattice, the Cr³⁺ ion occupies Ca/Y sites in the dodecahedron Ca/YO₈ and Mg sites in the octahedron MgO₆, giving rise to two distinct Cr³⁺ luminescence centers. Remarkably, the emission at 100 °C remained at 92% of its room temperature intensity and 81% at 150 °C, showcasing its exceptional thermal stability. The internal quantum efficiency (IQE) reached an impressive 81.1%, with an activation energy ΔE of 0.324 eV. Furthermore, we integrated the CYMG:Cr³⁺ phosphor with a commercial 450 nm blue chip to fabricate a micro NIR pc-LED, which exhibited stable NIR emission across different driving currents, with a NIR output power of 49.65 mW@400 mA and a photoelectric conversion efficiency of 10.52% at 20 mA. All findings highlight CYMG:Cr³⁺ as a stable and efficient broadband luminescent material for high-performance NIR LEDs.

The synthesis of a homoleptic azide-functionalised Au(I) bis-1,2,3-triazole-5-ylidene complex is reported, starting from a backbone-modified 1,2,3-triazolium salt ligand precursor. The incorporated azide handle allows for a straightforward modification of the complex according to click-chemistry protocols without impacting the steric shielding around the metal center, demonstrating the superiority of the presented triazole ligand framework over imidazole based systems. Employing the SPAAC and the CuAAC reactions, post-modification of the complex is facilitated with two model substrates, while retaining very high antiproliferative activity (nanomolar range IC₅₀ values) in A2780 and MCF-7 human cancer cells.

We studied the Ni–Cu-acid multifunctional synergism in NiCu-phyllosilicate catalysts toward 1,4-butynediol hydrogenation to 1,4-butanediol by varying the reduction temperature, which can activate different bimetal and support interactions. Compared with a monometallic Ni phyllosilicate (phy), which only showed one type of metal species when reduced at ∼750 °C, there are three types of metal species for the bimetallic Ni–Cu-phyllosilicate derived catalysts, namely Cuphy, differentiated Ni, and Niphy. Thorough structure–activity/selectivity correlation investigations showed that, although the Ni₉Cu₁-P catalyst matrix can produce tiny amounts of differentiated Ni⁰ species under the induction of reduced Cu⁰ at R250 condition, it could not form Ni–Cu bimetallic interactions for the collaborative hydrogenation of 1,4-butynediol, and the product stays in the semi hydrogenated state. When the reduction temperature is raised to 500 °C, stable Ni–Cu alloy active sites exist, accompanied by the strong metal support interaction and metal acid effect derived from the intimate contact between the extracted metal sites and the surviving functional phyllosilicate support; these functionalities yield a supreme hydrogenation performance of the R500 sample with a 1,4-butanediol yield larger than 91.2%.

Since their discovery in 1966, scorpionate ligands have been utilized to make coordination compounds for a variety of applications such as: studying organometallic reactions, biomimetic complexes, light-emitting materials and single-ion magnets. The recent development of a solvent-free pyrazole substitution chemistry has yielded the quantitative synthesis of asymmetrically functionalized all-pyrazole heteroscorpionate ligands. In this frontier article, we highlight the utility of all-pyrazole heteroscorpionates, specifically, nitro-trispyrazolylborates, in f-element chemistry. They offer great versatility in coordinating ability, donor strength, steric bulk and even optical charge transfer properties, all of which can be used to tune the properties of resultant complexes with metal ions. We show how they can impart structural diversity, sensitize Ln³⁺ luminescence and engender magnetic anisotropy and slow magnetic relaxation in the ion they coordinate. Additionally, we comment on the future of functionalized trispyrazolyl scorpionates, which includes enabling post-synthetic modifications of f-element complexes and becoming a platform to study the electronic properties of low oxidation state actinides.

A simple and mild stimulus-responsive fluorescent supramolecular polymer network was constructed from a pillararene-based multi-functional monomer through multiple noncovalent interactions and used as a rewritable paper.