Jacek Bogdan Jasinski

Palladium-catalyzed cross-couplings are frequently limited by off-cycle deactivation pathways, particularly phosphine deligation followed by aggregation of Pd(0) to catalytically inactive palladium black. We report an “on-cycle enforcement” strategy that employs a cooperative, nonalloyed trimetallic assembly─Pd(0), Cu(I), and Mn(III)─confined within PS-750-M/HPMC micelles in water. In this architecture, Pd mediates the canonical oxidative addition and reductive elimination steps, Cu(I) accelerates transmetalation via a Cu-nucleophile intermediate, and Mn(II/III) serves as a redox buffer that likely continuously reoxidizes off-cycle Pd(0) to micelle-soluble Pd(II), followed by its religation and reduction, thereby preventing Pd black formation. Spectroscopic analysis─transmission electron microscopy, scanning transmission electron microscopy–high-angle annular dark-field imaging, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy─reveals that the three metals remain spatially separated in the assembly yet electronically complementary within a phosphorus-rich matrix, enabling persistent catalytic activity. The resulting platform supports rapid, selective C–C couplings at 45 °C with broad substrate compatibility, including heteroarenes and terminal olefin─containing partners, without olefin interference. The catalyst displays exceptional longevity, minimal metal leaching (<1 ppm), and robust scalability, with multicycle reactions and gram-scale processes proceeding efficiently even after extended catalyst storage. These findings establish redox-buffered, compartmentalized trimetallic assemblies as a general solution to enforcing on-cycle Pd catalysis in water.

Co-precipitation surpasses solid-state synthesis of Na _0.67 Fe _0.5 Mn _0.5 O ₂ cathodes by producing finer and more homogeneous morphology and enhanced Na ⁺ diffusion,leading to superior electrochemical stability in sodium-ion batteries.

Aryl nitriles are important synthons in organic chemistry, yet conventional cyanation methods mostly generate free cyanide ions, creating acute safety hazards and wastewater contamination issues. We report a Pd-catalyzed cyanide ion-free cyanation of aryl halides featuring a transmetallation potentially via halogen (X)-cyanide (CN⁻) metathesis using potassium ferrocyanide as a bound CN⁻ reservoir. Mechanistic studies, CN⁻-sensing strip tests, and IR spectroscopy confirm that no free CN^– is released at any stage, eliminating toxicity and downstream CN⁻ liabilities. Stable AshPhos−Pd nanoparticles formed within HPMC enable efficient cyanation across diverse (hetero)aryl bromides and chlorides under mild conditions. This approach likely combines process safety and environmental compliance, offering a scalable solution for late-stage CN⁻ installation without the risks associated with free cyanide.

Palladium hydrides (PdH_x) are significant to hydrogen-transfer chemistry, yet their prolonged aqueous and air instability as well as their reliance on strong ligands for stabilization have limited their practical applications. Herein, we report dynamic micelle-enabled stable PdH_x nanoparticles that are readily generated and suspended within nonionic micelles. This synthesis process employs Pd(OAc)₂ as the Pd precursor, MeMgBr as the reductant, amphiphile PS-750-M as shielding nonionic micelles, and water as the dispersion medium. These hydride-rich nanophases persist for more than 1 year in air-saturated moisture, overcoming the canonical fragility of such metal hydrides in protic media. The micellar architecture provides hydrophobic compartments that shield PdH_x from proton-induced decomposition while maintaining access to H₂ and substrate for catalysis. These hydrides were found to be basic in nature, as evidenced by external base-free catalytic detriflation, a transformation otherwise known to generate triflic acid in situ. Pd K-edge X-ray absorption and ¹H nuclear magnetic resonance spectroscopy confirm the presence of persistent PdH_x species. The long-term stability and catalytic activity of these PdH_x@micelles are significant for materials chemistry and catalysis.

Van der Waals layered magnetic materials have recently received significant attention for their ability to exhibit antiferromagnetic or ferromagnetic (FM) properties, even at the few-layer or monolayer scale. Among them, Fe ₃ GeTe ₂ is one of the most extensively studied systems, crystallizing in a hexagonal structure as an itinerant FM with a Curie temperature ( T _C ) of ∼220 K in bulk form and strong magnetic anisotropy. In this study, temperature and magnetic field dependence of the four-probe resistance ( R x x ) ,   thermopower (TEP) ( S ), and Hall resistance ( R x y ) were investigated in thick Fe ₃ GeTe ₂ flakes with different thicknesses to understand electron and spin transport, as well as spin and magnetic states. R x x decreased with decreasing temperature, confirming metallic behavior, consistent with the observed reduction in the magnitude of the negative TEP. Negative magnetoresistance (MR) with the magnetic field normal to the sample plane exhibited a quadratic field dependence below T _C . An anomalous Hall effect was observed below T _C , where R x y ( B   ) showed a linear field dependence at low fields and saturation at higher fields. The anomalous Hall resistance ( R x y A ) followed a dependence of α R x x + β R x x 2 . A positive in-plane MR was observed when the current was perpendicular to the magnetic field, attributed to increased scattering from the enhanced Lorentz force and related orbital effects. Additionally, a hysteresis behavior was observed when cycling the in-plane magnetic field, likely due to the delay in domain alignment in response to the changing field.