Recent lbnl_es_cs items

Catalytic Borylation of Poly(vinyl chloride) Produces Adhesive Materials

Mon, 31 Aug 2026 00:00:00 +0000

Postpolymerization functionalization of polymers can create new applications for existing materials, while retaining their most favorable, intrinsic properties. Polyvinyl chloride (PVC) is a widely used, commodity polymer that is particularly challenging to modify. We report a copper-catalyzed protocol that replaces a small fraction of the C-Cl bonds in PVC with C-B bonds to boronic esters. The reaction occurs with an inexpensive catalyst comprising copper(II) chloride and an NHC ligand derived from a common ionic liquid that is distinct from the N-heterocyclic carbene (NHC) used for the borylation of small alkyl halides. The resulting materials adhere strongly to common surfaces, such as glass and metals, even more strongly than do commercial glues.

Photoreactivity of Ru2+ Polypyridyl Complexes Bearing the H2S‑Releasing Compound GYY4137

Thu, 27 Aug 2026 00:00:00 +0000

Ruthenium (Ru) polypyridyl complexes have been extensively used as optical probes, photoactivated anticancer agents, and photocages for biologically active ligands. In this study, Ru²⁺ polypyridyl complexes were investigated as photoreleasing agents for the H₂S donor GYY4137. Four complexes of the general formula cis-[Ru(NN)₂(GYY4137)]⁺, where NN = 2-2'-bipyridine (bpy), 2,2'-biquinoline (biq), 4,4'-methoxy-2,2'-bipyridine (dmobpy), and 4,4'-di-tert-butyl-2,2'-bipyridine (dtbpy), were synthesized and characterized by NMR spectroscopy and X-ray crystallography. The photochemical reactivity of these complexes was investigated, revealing that ligand photodissociation occurs in a two-step reaction. For these reactions, long-lived intermediates where the bidentate ligands attain a monodentate coordination mode could be detected. Furthermore, the ancillary diimine ligands dictated the identity of the final photoproducts observed,...

Hydrogen Electrocatalysis on Perfluorosulfonic-Acid-Coated Pt

Thu, 27 Aug 2026 00:00:00 +0000

Membrane-electrode assemblies utilize ionomer-coated electrocatalysts to achieve facile ion transport. Consequently, isolation of intrinsic catalyst kinetics from measured polarization curves is challenging, as the properties of the catalyst and ionomer both affect the measurements. Here, we employ a Pt microelectrode coated by a thin perfluorosulfonic acid (PFSA) layer to measure polarization curves for the hydrogen oxidation reaction/hydrogen evolution reaction (HER/HOR). Intrinsic electrode kinetics are isolated by theoretical analysis of the local catalyst microenvironment, accounting for mass transport and thermodynamics. The observed enhancements in HER and HOR rates with increasing relative humidity (RH) at the working electrode are attributable to two competing factors: the decrease in activity of H+ in the ionomer and the dominant decrease in the water reorganization energy in the Marcus–Hush–Chidsey representation of HER/HOR kinetics. The increase in intrinsic rate with...

Generalizable Porous Aromatic Framework‐Included Polymer Membranes for Diffusion‐Enhanced Gas Separations

Thu, 27 Aug 2026 00:00:00 +0000

Industrial separation processes account for 10-15% of global energy consumption. Membrane-based processes are less energy-intensive than traditional gas separation technologies; however, enhanced material separation performance and stability for numerous gas mixtures are needed for widespread industrial adoption. This work presents a generalizable strategy for preparing mixed-matrix gas separation membranes exceeding the performance upper bounds of existing polymer membranes for a wide variety of industrial gases. By incorporating robust porous aromatic framework (PAF) particles into various dense commercial polymer matrices, gas diffusivity and solubility can be enhanced. For diverse gas mixtures (e.g., CO₂/N₂, O₂/N₂, He/CH₄, H₂/N₂, and C₂H₄/C₂H₆), the resulting composite membranes exhibit enhanced gas permeabilities-by as much as 520%-and largely unchanged...

Machine-Learned Leftmost Hessian Eigenvectors for Robust Transition State Finding

Wed, 26 Aug 2026 00:00:00 +0000

The reliable determination of transition states (TSs) benefits from second-order information for robust convergence and validation, but the computational expense of Hessians prohibits their routine use in TS optimization. Here, we present a machine-learning-driven TS optimizer that directly predicts the leftmost Hessian eigenvector (LMHE), which is the critical mode that locally approximates the reaction coordinate encompassing the TS. We demonstrate that our LMHE optimizer recovers TS solutions at the same rate as full-Hessian optimizers and robustly from degraded initial guess geometries, thereby eliminating the excessively long wall times characteristic of full-Hessian approaches and reducing total gradient evaluations compared to standard quasi-Newton methods. We further improve accuracy and robustness using uncertainty quantification for identifying occasional LMHE prediction failures, where we then fall back to a full-Hessian update from the machine-learned potential at...

Oxidative Cascade Cyclization of 1,2-Dicyanoarenes by a Dicopper(I,I) Nitrite Complex to Phthalimide Ligands

Fri, 21 Aug 2026 00:00:00 +0000

The reactions of [Cu2(μ–κ 1:κ 1 -O2N)DPFN][NTf2] (1; DPFN = 2,7-bis(fluoro-di(2-pyridyl)methyl)-1,8-naphthyridine, NTf2 – = N(SO2CF3)2 –) with 1,4-dicyanobenzene and 1,2-dicyanoarenes are discussed. Treatment of 1 with 1,4-dicyanobenzene produces a tetra-Cu(I) terephthalate complex (2) and dinitrogen via a discrete CN triple bond cleavage at each cyano group. However, reactions of 1 with 1,2-dicyanoarenes appear to proceed via a cascade reaction involving two intertwined CN triple bond activations to yield a series of di-Cu(I) phthalimides, [Cu2(μ–N(CO)2(Ar))DPFN][NTf2] (3-(Ar); Ar = 1,2-arylenes C6H4, 3-NO2C6H3, 4-NO2C6H3, 4-PrOC6H3, 3-NC5H3) and dinitrogen. The dicopper phthalimide bonding interaction in these compounds is robust enough to resist protonation by pentafluorophenol and alkylation by methyl triflate or benzyl chloride at the imide nitrogen. This characteristic presents an opportunity for postsynthetic modifications of the phthalimide ligand. Nevertheless,...

Advancing Battery Manufacturing: Synchrotron Characterization for Industry

Fri, 21 Aug 2026 00:00:00 +0000

Large-scale battery manufacturing requires understanding the fundamental principles of materials and interfaces and relies on advanced techniques for detailed interrogation. Despite advancements in the industrial scale production and their associated quality control tools, challenges such as electrode heterogeneity, internal defects, and large-scale material waste (e.g., scrap) can hamper manufacturing. Synchrotron X-ray characterization techniques offer spatial, temporal, and chemical resolution that can provide diagnostic insights for metrology across various manufacturing steps. This review examines the use of synchrotron tools to advance understanding of key steps in the battery manufacturing process. Recent examples demonstrate how synchrotron methods resolve manufacturing challenges and uncover degradation pathways that are otherwise inaccessible. Future directions for advancing battery manufacturing emphasize collaboration between academia and industry through the use of...

Dramatic Slowdown of Bimolecular Reactions of Criegee Intermediates in Organic Aerosols

Fri, 21 Aug 2026 00:00:00 +0000

Although Criegee intermediates (CIs) play a central role in driving the transformation of organic molecules, their condensed-phase reaction kinetics remains poorly understood. While CIs undergo unimolecular decomposition to produce OH radicals, stabilized CIs participate in a host of other bimolecular reactions forming larger molecular weight products, including secondary ozonides (k_SOZ), alkoxyalkyl hydroperoxides (k_AlAHP), and acyloxyalkyl hydroperoxides (k_AcAHP). Here, we demonstrate, using prior literature and new measurements of heterogeneous organic aerosol reactions using O₃ or OH radicals, that these condensed-phase bimolecular reaction rate coefficients k_SOZ (10^-20 cm³·molecule^-1·s^-1), k_AlAHP, and k_AcAHP (10^-19 cm³·molecule^-1·s^-1) are 7-10 orders of magnitude slower...

Molecular Mass Growth Processes to Polycyclic Aromatic Hydrocarbons through Radical–Radical Reactions Exploiting Photoionization Reflectron Time-of-Flight Mass Spectrometry

Fri, 21 Aug 2026 00:00:00 +0000

ConspectusPolycyclic aromatic hydrocarbons (PAHs) represent critical building blocks in molecular mass growth processes to carbonaceous nanoparticles, referred to as interstellar and circumstellar grains along with soot particles in astrophysical environments and combustion systems, respectively. Recent advancements on elucidating elementary steps to PAHs have utilized reactions of aromatic radicals, resonantly stabilized free radicals, and aliphatic radicals with closed shell hydrocarbons. However, the role of radical-radical reactions (RRRs) leading to PAHs has remained largely unexplored on the molecular level due to preceding experimental challenges in producing sufficiently high number densities of radical reactants for isomer-selective detection of products from bimolecular and termolecular reactions. This Account offers the latest developments in our knowledge on the mechanisms and pathways to PAHs via RRRs probed in a chemical microreactor at temperatures as high as 1600...

Plutonium(III) versus uranium(III) and samarium(III) in small molecule activation chemistry

Thu, 20 Aug 2026 00:00:00 +0000

We report the PuIII complex, [PuIII(CpMe4)3] (1-Pu), and demonstrate its differences in small molecule reactivity compared to the UIII and SmIII analogs, [UIII(CpMe4)3] (1-U) and [SmIII(CpMe4)3] (1-Sm), respectively. 1-Pu reductively cleaves the small molecule (PhS)2, affording a PuIII complex, [{PuIII(CpMe4)2}2(μ-SPh)2] (2-Pu), while retaining the PuIII center and eliminating (CpMe4)2 as a by-product, a fingerprint of a sterically induced reduction (SIR) reaction. Sm is often used as a surrogate for Pu, but the analogous [SmIII(CpMe4)3], (1-Sm), is unreactive. The (PhS)2 cleavage by 1-U proceeds solely via a metal-based oxidation (i.e., UIII → UIV), to form [UIV(CpMe4)3(SPh)] (3-U). Only 1-U reacts with (PhHN)2, affording the reductive cleavage product, [UIV(CpMe4)3(NHPh)] (4-U). The difference in reactivity of 1-Pu compared to complexes 1-Sm and 1-U was unexpected, and since SIR chemistry can enable complexes to participate in otherwise impossible reductive transformation of...

Structural and spectroscopic characterization of a Tb(IV) polyoxometalate

Wed, 19 Aug 2026 00:00:00 +0000

There has been a renaissance in high valent lanthanide chemistry, which has resulted in the first examples of tetravalent praseodymium (Pr) and terbium (Tb) in molecular systems. These feats have been achieved with tailored ligands that facilitate tetravalent lanthanide stability in non-aqueous conditions. The next step in realizing the potential of high valent lanthanide chemistry is moving towards complexes that are stable in ambient and aqueous conditions. In this investigation, we advance this paradigm by obtaining definitive evidence of Tb(IV) in a molecular system under aqueous conditions utilizing the lacunary Wells-Dawson polyoxometalate, K10P2W17O61•20H2O. Herein we present the single crystal structure of K16Tb(IV)(P2W17O61)2•39.85H2O (Tb(IV)W34) as well as extensive spectroscopic evidence obtained via UV–Vis-NIR, X-ray absorption near edge spectroscopy, continuous wave X-band electron paramagnetic resonance spectroscopy and SQUID magnetometry measurements to confirm...

Mitigation of hydrogen crossover in liquid alkaline water electrolysers using gas recombination catalysts

Tue, 18 Aug 2026 00:00:00 +0000

The rising demand for hydrogen calls for improvements in the efficiency of liquid alkaline water electrolysers (LAWEs), which can be fulfilled by advanced electrodes or separators. Nevertheless, they also intensify hydrogen crossover and safety concerns, thus mandating efficient mitigation strategies. Here we studied the correlation between cathodes and hydrogen crossover behaviours and mitigated safety risks by designing a gas recombination catalyst (GRC). We attribute the elevated hydrogen crossover associated with platinum-based cathodes to their preferential utilization for the hydrogen evolution reaction that creates elevated hydrogen supersaturation, as evidenced by direct measurements of dissolved hydrogen concentration. Varying the placement of platinum layers relative to the cathode–separator interface also supports this conclusion. The implementation of a GRC reduces hydrogen crossover by 95% without affecting LAWE performance and functions for over 1,000 h at 1 A cm−2....

Catalytic Ambient Temperature Dinitrogen Conversion to a Bis(silyl)amine by Mononuclear Group 4 Aryloxide Complexes

Tue, 18 Aug 2026 00:00:00 +0000

The homogeneous conversion of ambient dinitrogen to amine products via the N₂ reduction reaction (N₂RR) remains a prized yet challenging feat for d-block complexes and is scarcely reported for f-block complexes. New, mononuclear Ti^IV and Zr^IV aryloxide complexes Ti(DP)₂ (1Ti), Zr(DP)₂ (1Zr), and DP = [2-(OC₆H₂-2-^tBu,4-Me)₂CHPh] produce up to 51 eq. and up to 7.0 eq. of HN(SiMe₃)₂ per Ti/Zr, from N₂, K⁰, weak acid, and chlorotrimethylsilane. Complex 1Ti exhibits more than double the activity toward N₂-silylation of any previously reported Ti N₂RR catalyst and can also catalyze the formation of up to 19 eq. of NH₃, a new feature in early metal N₂RR chemistry. The mononuclear 1Zr is the most active Zr catalyst for N₂-silylation to date. [KSm(DP)₂(THF)₃]...

Structure of iridium oxide catalysts dictates performance differences for proton exchange membrane water electrolyzers

Fri, 31 Jul 2026 00:00:00 +0000

A systematic catalyst loading study reveals the higher catalytic activity of amorphous iridium oxide arises from bulk participation via suggested electrochemical descriptors, while identifying loading-independent intrinsic electrochemical properties. Proton exchange membrane water electrolyzers (PEMWEs) are promising zero-emission technologies. However, their high cost remains a barrier to widespread adoption. Iridium oxide is commonly used as an oxygen evolution reaction (OER) catalyst, and its cost and scarcity make it essential to reduce its loading while increasing its activity. Evaluation of iridium oxide activity should be carried out in the membrane electrode assembly (MEA) configuration to replicate realistic operating conditions. Herein, we present a comprehensive benchmarking framework to accurately evaluate the amorphous and crystalline iridium oxides at the MEA level. By systematically varying the catalyst loading, this study confirmed that each MEA was utilized...

Attosecond response of molecules to impulsive ionization

Wed, 29 Jul 2026 00:00:00 +0000

When matter interacts with energetic radiation it can undergo sudden, or impulsive, ionization. This process can drive chemical change and occurs widely in space and planetary atmospheres, yet its comprehensive description challenges our current theoretical and computational capabilities as it requires advanced treatment of electron correlation and nonadiabatic dynamics beyond the Born–Oppenheimer approximation. Here we measure the response of the para-aminophenol molecule to sudden ionization. Using attosecond X-ray absorption spectroscopy, we resolve the ultrafast dynamics of the ionized molecule with atomic precision. A subfemtosecond decay corresponds to states undergoing non-radiative decay, whereas few-femtosecond oscillatory signatures are associated with electronic wavepacket motion in stable cation states that later couple to nuclear motion. We compare our measurement with state-of-the-art computational modelling, qualitatively reproducing the observed response across...

Toward Hydrogen Isotope Separations through Strong Hydrogen Adsorption at Open Copper(I) Sites in an Ultramicroporous Metal–Organic Framework

Wed, 29 Jul 2026 00:00:00 +0000

Metal-organic frameworks with coordinatively unsaturated metal sites (open metal sites) capable of engaging in orbital interactions with π-acidic gases are of interest for enabling ambient-temperature gas separations, such as hydrogen isotope separations. In view of the weakly π-acidic nature of H₂, we sought to strengthen π-backbonding-mediated H₂ adsorption through pore confinement effects. Toward that end, we synthesized and characterized the ultramicroporous metal-organic framework Cu_xZn_5-xCl_4-yH_z(bbta)₃ (Cu^IZn-MFU-4; H₂bbta = 1H,5H-benzo(1,2-d:4,5-d')bistriazole), featuring π-basic trigonal pyramidal Cu^I sites that reside within 7 Å of one another at their closest. Gas adsorption measurements reveal an H₂ adsorption enthalpy of -38 kJ/mol, exceeding that of the larger-pore analog (Cu^IZn-MFU-4l;...

Catalytic visible light-driven alkane dehydrogenation by a di-uranyl germanotungstate

Tue, 28 Jul 2026 00:00:00 +0000

The dehydrogenation of alkanes to alkenes is an appealing strategy for upgrading abundant hydrocarbons, yet it is constrained by the inherent challenge of cleaving two inert C(sp³)-H bonds with selectivity and without overoxidation. We report a cooperative photocatalytic dehydrogenation of unactivated cycloalkanes under visible light irradiation enabled by a new dinuclear uranyl complex supported by an oxidatively stable germanotungstate, [NBu ⁿ ₄]₈[(UO₂)₂(GeW₁₀O₃₄(µ₂-OH)₂)₂]·(CH₃)₂CO (1). The uranyl complex catalytically converts cyclooctane to cyclooctene under ambient conditions with a TON per molecule of 44 and 9,10-dihydrophenanthrene to phenanthrene with a TON of 73 per molecule, using 1 mol% 1 in MeCN solution, under 427 nm irradiation, using [S₂O₈]^2- or chloranil (C₆Cl₄O₂)...

Hybrid biophysical systems for atmospheric CO2 capture

Tue, 21 Jul 2026 00:00:00 +0000

Negative emissions technologies will be essential for limiting anthropogenic global temperature increases to 2 °C in the later years of the 21st century. Carbonic anhydrase (CA) metalloenzymes catalyze the otherwise slow conversion of CO2 into carbonic acid (H2CO3), suggesting their utility in the rapid hydration and downstream capture of dissolved CO2 in aqueous media for a variety of CO2 capture methods, such as thermal and pH swings and mineralization. The possibility of driving the rapid capture of CO2 by catalyzing the CO2 hydration bottleneck carries real potential for realizing efficient direct air capture (DAC) and direct ocean capture (DOC) systems. However, scaled application of CAs will be dependent on some way of economically sourcing the enzymes at volumes relevant to scaled DAC/DOC operations. In this perspective, we consider the prospect of catalyzing CO2 hydration using a CA that is bound to the outer membrane of a cyanobacterial host, engineered constructs we...

Assembly and Reactions of Artificial Metalloenzymes in Streptomyces albus

Thu, 16 Jul 2026 00:00:00 +0000

Artificial metalloenzymes (ArMs) expand the suite of synthetically valuable, new-to-nature biocatalytic reactions. Integrating these enzymes into biosynthetic pathways enables reactions not found in nature to occur in living cells with the intermediates or products of the metabolic pathways. However, the integration of reactions catalyzed by ArMs into complex metabolic pathways is constrained by the lack of methods to assemble these ArMs in organisms that are commonly used for metabolic engineering. We report the assembly of an iridium-containing artificial metalloenzyme (Ir-ArM) in Streptomyces albus, a Gram-positive bacterial chassis widely used for the heterologous expression of natural products. In this engineered organism, the Ir-ArM assembles in the cytoplasm and catalyzes abiological carbene transfer to the unactivated, disubstituted double bond of an exogenously added terpene with turnover numbers (TONs) that are two times higher than those for the same reaction...

Identifying predictive hematological biomarkers for radiation exposure by machine learning in mouse models

Tue, 14 Jul 2026 00:00:00 +0000

BackgroundPopulation-scale radiation exposure assessment during radiological emergencies is hindered by the slow and costly nature of current methods, creating a need for rapid, affordable screening tools. Radiation biodosimetry using peripheral blood counts is a promising approach, but estimating low-dose exposures and exposure at extended time points remains challenging, especially when accounting for inter-individual differences in radiation sensitivity.MethodsWe analyze complete blood count (CBC) profiles from a retrospective cohort of 1151 male and female BALB/cJ and C57BL/6 J mice exposed to total-body X-ray radiation at doses ranging from 0.05 to 4 Gy. CBCs are collected 1 to 150 days post exposure. We develop a predictive model of radiation exposure using a sparse representation learning strategy to identify the most informative CBC parameters. Model performance is evaluated through exhaustive cross-validation and validated in a double-blind prospective cohort of 431 animals....

Measurement of the Critical Ionization Level for Resist Polymer Dissolution Using a Polypeptoid Platform

Tue, 14 Jul 2026 00:00:00 +0000

Reactive dissolution of a photoresist polymer in aqueous base to form a processable image is an important step in building patterns on semiconductor chips. The critical ionization (CI) theory states that a specific minimum fraction, the CI level, of the ionizable moieties in the exposed polymer is required for the chain to become soluble. This fraction’s value strongly influences pattern quality but has only been estimated in prior studies. Here, the CI level of a specific polymer platform has been measured to be 20% using a family of polypeptoids. This platform has controlled chain length, ionizable monomer content, and chain end groups. Using reaction-diffusion chemical kinetics modeling, we show that polypeptoids dissolution above the CI level is consistent with theory. At the CI level, qualitatively different gelation-dissolution behavior occurs compared to levels above it. The methodology used in this work is broadly applicable to understanding fundamental aspects of reactive...

A Gauss-Radau-Laguerre Discrete Variable Representation for Use in Continuum Electron Dynamics

Tue, 7 Jul 2026 00:00:00 +0000

We detail an implementation, suitable for calculations on highly correlated ionizing systems, of a modified finite element discrete variable representation (FE-DVR) appended with a Gauss-Radau-Laguerre element. The appended element includes exterior complex scaling (ECS) to impose outgoing wave boundary conditions on treatments of processes involving continuum electrons. In this "infinite range" ECS (irECS), the complications that introduce reflections from the end of the grid when the last ECS finite element has finite range are avoided by the use of the Laguerre-weighted exponentially decaying tails, while outgoing wave boundary conditions are still imposed via the ECS transformation. For highly correlated systems in the absence of strong external fields we find that accurate two-electron integrals are essential in this modified FE-DVR. To accurately compute the two-electron integrals over the entire ECS contour, we present a detailed examination of the implications from the...

Microcarbonation of Naphthalene: An Experimental and Computational Study of Photoionization in Naphthalene-Carbon Dioxide Clusters

Wed, 1 Jul 2026 00:00:00 +0000

The photoionization of naphthalene (N)-carbon dioxide (CO₂) clusters was studied using tunable vacuum ultraviolet (VUV) radiation from a synchrotron in the photon range of 8.0 to 13.7 eV, in combination with time-of-flight mass spectrometry. Clusters of monomer, dimer, and trimer naphthalene with CO₂ (N(CO₂)_0-6, N2(CO₂)_0-3, N3) were observed. The lowest-energy conformers were obtained via a conformer search, followed by geometry optimizations at the ωB97X-V2/aug-cc-pVTZ (monomer) and ωB97X-V2/aug-cc-pVDZ (dimer) levels of theory. Carbon dioxide was found to preferentially cluster on top of the naphthalene molecule (in an out-of-plane configuration). From the mass spectra, photoionization intensity curves (PICs) were constructed, and appearance energies (AEs) were determined. No substantial trend in AE was observed with increasing size of the naphthalene-carbon dioxide clusters; rather, AE oscillations around...

Random heteropolymers as enzyme mimics

Wed, 1 Jul 2026 00:00:00 +0000

Despite successes in replicating the primary–secondary–tertiary structure hierarchy of protein, it remains elusive to synthetically materialize protein functions that are deeply rooted in their chemical, structural and dynamic heterogeneities1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11–12. We propose that for polymers with backbone chemistries different from that of proteins, programming spatial and temporal projections of sidechains at the segmental level can be effective in replicating protein behaviours13,14; and leveraging the rotational freedom of polymer can mitigate deficiencies in monomeric sequence specificity and achieve behaviour uniformity at the ensemble level2,3,15, 16, 17, 18, 19–20. Here, guided by the active site analysis of about 1,300 metalloproteins, we design random heteropolymers (RHPs) as enzyme mimics based on one-pot synthesis. We introduce key monomers as the equivalents of the functional residues of protein and statistically modulate the chemical characteristics...

Optimized Auxiliary Functions for Robust Mitigation of Finite-Size Errors in Periodic Hybrid Density Functional Theory

Wed, 1 Jul 2026 00:00:00 +0000

When calculating properties of periodic systems at the thermodynamic limit (TDL), the dominant source of finite size error (FSE) arises from the long-range Coulomb interaction, and can manifest as a slowly converging quadrature error when approximating an integral in the reciprocal space by a finite sum. The singularity subtraction (SS) method offers a systematic approach for reducing this quadrature error and thus the FSE. In this work, we first investigate the performance of the SS method in the simplest setting, aiming at reducing the FSE in exact exchange calculations by subtracting the Coulomb contribution with a single, adjustable Gaussian auxiliary function. We demonstrate that a simple fitting method can robustly estimate the optimal Gaussian width and leads to rapid convergence toward the TDL. Furthermore, we suggest new forms of the auxiliary function, whose optimal parameters could also be determined through least-squares fitting. For a range of semiconductors and insulators,...

Scanning transmission x-ray microscopy (STXM) of plutonium oxide

Tue, 30 Jun 2026 00:00:00 +0000

Scanning transmission x-ray microscopy was used to examine plutonium oxide particles formed by the corrosion of δ-phase plutonium alloy under high-humidity conditions. O K-edge spectra collected from eight distinct particles displayed significant spectral differences, revealing heterogeneity in oxidation states within a single sample batch. This variation suggests complex chemical environments and formation histories, which are important considerations for nuclear forensic investigations. These findings highlight both the potential of synchrotron-based x-ray microscopy for nondestructive, high-resolution analysis of nuclear materials and the need for expanded reference datasets to improve the interpretation and forensic utility of such measurements.

Ion-exchange-mediated pre-association gates interfacial PCET

Tue, 30 Jun 2026 00:00:00 +0000

Interfacial proton-coupled electron transfer (I-PCET) is typically viewed as a single elementary reaction despite general recognition that analogous solution-phase reactivity requires proton donor-acceptor pre-association. Herein, we examine the role of pre-association in I-PCET to a graphite-conjugated carboxylic acid (GC-COOH) surface by quantifying electrolyte pH and I-PCET kinetics as a function of NaClO4 concentrations up to 17 mol kg−1. In acidic and acetate-buffered media, we observed attenuations in the I-PCET rate relative to those expected given the solution pH. To account for the influence of electrolyte concentration on I-PCET rate, we propose a multiple-step model wherein the exchange of interfacial Na+ for H3O+ to form a hydrogen-bonded pre-association complex precedes rate-limiting concerted proton-electron transfer. In this model, the increased electrolyte concentration inhibits H3O+ pre-association, a phenomenon that is recovered in molecular dynamics simulations....

Exponential crystallization in corals

Mon, 29 Jun 2026 00:00:00 +0000

Corals form their reef-building aragonite (CaCO3) skeletons via transient precursor phases yet understanding of the dynamics of these early-stage transformations remains incomplete. Using time-independent myriad mapping (MM) at 50 nm resolution, we map five mineral phases near the skeleton surface of Stylophora pistillata corals grown in varying seawater pH. All precursors, crystalline and amorphous, exhibit a consistent exponential decay from the growth front, with a shared decay length of 0.7 ± 0.1 μm, independent of time, phase, or pH. This spatial decay, paired with the constant growth rate of the skeleton, reveals a decay time of 5.1 ± 0.5 minutes. The dominant precursor is not amorphous but crystalline: calcium carbonate hemihydrate (CCHH, CaCO₃·½H₂O). These results suggest that exponential crystallization kinetics govern coral biomineralization and may be a widespread feature in biogenic, geologic, and synthetic systems—traceable long after initial mineral deposition.

Toward the performance assessment of advanced nuclear waste forms: temperature dependence of lanthanide borosilicate glass dissolution

Mon, 29 Jun 2026 00:00:00 +0000

Lanthanide borosilicate (LaBS) glasses are among the most promising waste forms for the immobilization of high-level radioactive waste generated from advanced nuclear fuel cycles. However, the temperature dependence of their dissolution kinetics remains poorly understood and constrained, limiting the integration of these materials into established performance assessment models. Here, we investigate the dissolution behavior of the legacy AmCm2-19 LaBS glass and the benchmark alkali aluminoborosilicate ISG-1 in deionized water between 50 °C and 250 °C using ASTM C1285 (Product Consistency Test-B) protocols. For AmCm2-19 LaBS glass, normalized elemental release rates for boron and silicon increase with temperature before plateauing near 150 °C, consistent with solubility-limited behavior. From data obtained at 50 °C and 100 °C, Arrhenius analysis yields activation energies of Ea(B) = 24.8 ± 0.3 kJ mol⁻¹ and Ea(Si) = 14.4 ± 0.2 kJ mol⁻¹, similar or slightly lower than those previously...

Multi-level QTAIM-Enriched Graph Neural Networks for Resolving Properties of Transition Metal Complexes

Sun, 28 Jun 2026 00:00:00 +0000

Here we evaluate the robustness and utility of quantum mechanical descriptors for machine learning with transition metal complexes. We utilize ab initio information from the quantum theory of atoms-in-molecules (QTAIM) for 60k transition metal complexes at multiple levels of theory (LOT), presented here in the tmQM+ dataset, to inform flexible graph neural network (GNN) models. We evaluate these models with several experiments, including training on limited charge and elemental compositions 1 and testing on unseen charges and elements, as well as training on smaller portions of the dataset. Results show that additional quantum chemical information improves performance on unseen regimes and smaller training sets. Furthermore, we leverage the tmQM+ dataset to analyze how QTAIM descriptors vary across different LOT and probe machine learning performance with less computationally expensive LOT. We determine that ab initio descriptors provide benefits across LOT, thereby motivating...

Multi-level QTAIM-Enriched Graph Neural Networks for Resolving Properties of Transition Metal Complexes

Sun, 28 Jun 2026 00:00:00 +0000

Low-Temperature Non-Oxidative Coupling of Methane on Atomically Dispersed Titanium–Aluminum–Boron Nanopowder

Fri, 26 Jun 2026 00:00:00 +0000

Nonoxidative coupling of methane represents a long-standing challenge in heterogeneous catalysis, as it requires activation of the carbon-hydrogen (C-H) bond, controlled carbon-carbon (C-C) bond formation, and effective hydrogen management without relying on oxidants. Here, we report a low-temperature C-H activation and nonoxidative C-C coupling of methane over atomically dispersed titanium-aluminum-boron nanopowder (Ti-Al-B NP) utilizing a catalytic microreactor coupled to synchrotron single-photon photoionization reflectron time-of-flight mass spectrometry. The soft-ionization, in situ probing method detects the nascent reaction products and radical intermediates under operando conditions, including methyl radical, C2 hydrocarbons, and molecular hydrogen. Methane activation is initiated at 800 K, approximately 700 K below the gas-phase decomposition threshold, leading predominantly to ethylene formation with selectivity reaching up to 78% among the C-C coupled products....

Evolution of size-selected Pt cluster catalysts on prototypical oxide supports

Fri, 26 Jun 2026 00:00:00 +0000

The current quest for new pathways into sustainable, efficient and durable energy conversion technologies makes the used for a fundamental understanding of the atomic-scale phenomena underlying catalytic processes ever more pressing. In this context, characterizing catalyst particles in situ provides valuable information about the evolution of their composition, structure, oxidation state and charge state during an ongoing process. To disentangle the influence of individual parameters - temperature, pressure, gas composition, cluster size, as well as support acidity, redox state and defect density - it is crucial to control them precisely and separately in experiments. At the example of size-selected Pt_n clusters - i.e. sub-nm particles defined to the exact number of atoms - on flat oxide supports, we follow their rich evolution phenomena via (synchrotron-based) X-ray photoelectron spectroscopy (XPS) and scanning tunnelling microscopy (STM)...

High‐Performance Cu6Sn5 Alloy Electrocatalysts for Formaldehyde Oxidative Dehydrogenation and Bipolar Hydrogen Production

Fri, 26 Jun 2026 00:00:00 +0000

Aldehyde-assisted water electrolysis offers an attractive pathway for energy-saving bipolar hydrogen production with combined faradaic efficiency (FE) of 200% while converting formaldehyde into value-added formate. Herein we report the design and synthesis of noble metal-free Cu₆Sn₅ alloy as a highly effective electrocatalyst for formaldehyde electro-oxidative dehydrogenation, demonstrating a geometric current density of 915 ± 46 mA cm^-2 at 0.4 V versus reversible hydrogen electrode, outperforming many noble metal electrocatalysts reported previously. The formaldehyde-assisted water electrolyzer delivers 100 mA cm^-2 at a low cell voltage of 0.124 V, and a current density of 486 ± 20 mA cm^-2 at a cell voltage of 0.6 V without any iR compensation and exhibits nearly 200% faradaic efficiency for bipolar hydrogen production at 100 mA cm^-2 in 88 h long-term...

In Situ Formed Pt–Ga Hetero Duo-Atomic Catalyst for Efficient Hydrogen Storage in N‑Heterocycles

Fri, 26 Jun 2026 00:00:00 +0000

Efficient catalysts for the dehydrogenation and hydrogenation of liquid organic hydrogen carriers (LOHCs) are essential for advancing hydrogen storage and transportation. Conventional nanoparticle catalysts suffer from low metal utilization, while single-atom catalysts (SAC) are limited by isolated active sites. Here, we present a hetero duo-atomic catalyst, Pt₁-Ga₁/CeO₂ DAC, which exhibits exceptional activity, selectivity, stability, and recyclability for N-heterocycle hydrogen storage. Ga plays a critical role in C-H bond activation, acting as a mediator in catalytic bond-breaking and formation. Compared with Pt₁/CeO₂ SAC, Pt₁-Ga₁/CeO₂ DAC enhances metal utilization while overcoming SAC limitations for large substrates. This work establishes a promising strategy for designing highly efficient catalysts for LOHC applications.

Rotational coherence dominates early-time dynamics and produces long-time revivals in the S2 state of azulene

Thu, 25 Jun 2026 00:00:00 +0000

The ultrafast dynamics of azulene have been debated for decades, with reported picosecond decay constants variously attributed to intramolecular vibrational redistribution (IVR), internal conversion, or rotational dephasing. Using polarization- and femtosecond time-resolved resonance-enhanced multiphoton ionization spectroscopy with a nanosecond delay window, we disentangle this long-standing inconsistency and show that the early 2-5 ps decay component arises entirely from the rotational dephasing of an excited-state wavepacket. Identical time constants extracted from the decay of the parallel signal and the rise of the perpendicular signal across multiple vibronic origins provide an unambiguous rotational anisotropy signature, eliminating the need for IVR-based interpretations. Extending the measurement window to 1.3 ns reveals well-structured J-type and C-type rotational coherence revivals in S2 azulene on top of the well-documented fluorescence decay, demonstrating...

Consistent inclusion of triple substitutions within a coupled cluster based static quantum embedding theory

Thu, 18 Jun 2026 00:00:00 +0000

We have previously proposed the MPCC static embedding framework for quantum chemistry that self-consistently couples a high-level coupled cluster (CC) treatment of the fragment (active region) with a lower level, Møller-Plesset perturbation treatment of the environment. Our initial implementation was limited to single and double (SD) substitutions, with CCSD for the fragment and first-order perturbative SD amplitudes for the environment. Here, we extend the MPCC embedding treatment to triple substitutions, which is essential for achieving chemical accuracy in energy differences. To this end, we employ a CCSDT solver for the fragment subsystem. For the environment subsystem, we construct a perturbative estimate of the triples amplitudes, explicitly accounting for feedback from all fragment amplitudes. The resulting approach is denoted MPCCSDT(pt). We further introduce a more complete formulation in which feedback from the environment amplitudes to the fragment amplitudes is...

Si–Cl Bond Activations at Ni(0) to Give Bimetallic Ni(I) μ1,2-Cl–SiR1R2 Complexes that Undergo Selective Hydrogenolyses to R1R2SiH2 Dihydrosilanes

Thu, 18 Jun 2026 00:00:00 +0000

Chlorosilanes are cheap and abundant raw materials as crucial building blocks in silicon chemistry, yet the metal-mediated activation and functionalization of Si–Cl bonds typically require precious metal sources due to their thermodynamic inertness. Herein, we report the stoichiometric, facile activation, and hydrogenolysis of chlorosilanes mediated by a series of low-valent NHC–Ni (NHC = N-heterocyclic carbene) complexes. Treatment of a Ni(0) complex (IPr)Ni(η6-toluene) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene) with chlorosilanes (R1R2SiCl2, R1 = Cl, R2 = Cl, Me, Ph, or R1 = R2 = Me, Et, Ph, 4-MePh) rapidly afforded di-Ni(I) complexes with a bridging silyl ligand ([(IPr)Ni]2(μ-SiR1R2Cl)(μ-Cl), 1 R1,R2 ) in high yields. Use of a bulkier chlorosilane, Ph2SiCl2, allowed the isolation of the mono-Ni(II) silyl complex (IPr)Ni(SiPh2Cl)Cl (2 Ph ) as an intermediate generated via Si–Cl oxidative addition, which underwent comproportionation with (IPr)Ni(η6-toluene)...

SmileyLlama: modifying large language models for directed chemical space exploration

Wed, 17 Jun 2026 00:00:00 +0000

Here we show that large language models (LLMs) can be transformed via supervised fine-tuning of engineered prompts into SmileyLlama for exploring the chemical space of drug molecules. We benchmark SmileyLlama against pretrained LLMs and chemical language models trained from scratch for generating valid and novel drug-like molecules, and use direct preference optimization to both improve SmileyLlama’s adherence to a prompt and as part of the iMiner reinforcement learning framework to predict molecules with optimized three-dimensional conformations and high binding affinity to drug targets. By training an LLM to speak directly as a chemical language model, while retaining most of its natural language capabilities, we show that SmileyLlama can reliably generate molecules with user-specified properties rather than acting only as a chatbot with knowledge of chemistry or as a virtual assistant. While SmileyLlama is geared toward drug discovery, the supervised fine-tuning/direct preference...

Uranyl Tris(benzoate) Photocatalysts for Site-Selective Hydrocarbon Functionalization

Wed, 17 Jun 2026 00:00:00 +0000

The uranyl dication ([UO₂]²⁺) is a highly active photocatalyst for the functionalization of inert C_sp3-H bonds by direct hydrogen atom abstraction (HAA). However, photocatalysis by the uranyl ion remains underexplored. Most reports are limited to reactions catalyzed by simple uranyl salts, such as uranyl nitrate [UO₂(NO₃)₂·6H₂O] (U^NO3). We report a set of uranyl tris(benzoate) complexes 1-R containing strongly coordinating and tunable equatorial ligands that resist photodamage and control access to the oxo groups. These catalyst variants with appropriate aryl substituents undergo catalytic reactions at C-H bonds by HAA. The selectivity and reactivity of this step depend on the ligand framework and are distinct from that of U^NO3 or other photoactive oxo complexes, such as decatungstate, that lack ancillary ligands. Finally, consistent with the strong,...

Enamel nanocrystal misorientation increased with meat-eating and agriculture.

Wed, 17 Jun 2026 00:00:00 +0000

Enamel covers teeth, is the hardest tissue in the vertebrate body and has a complex multiscale structure from nanometres to millimetres1. The structure comprises thin, long hydroxyapatite (Ca5(PO4)3OH) nanocrystals2, 50-70 nm wide, many micrometres long, parallel and bundled into approximately 5-µm-wide rods. The rods undulate and cross into a microscale 'decussation pattern' that toughens enamel by deflecting cracks3,4. However, the crystallographic orientation of enamel nanocrystals is poorly understood. Here we show that the misorientation angle of adjacent nanocrystals varies markedly across 12 primate teeth spanning 9 species, 17.8 million years of evolution and diverse diets. Using a method called Polarization Enabled Large Input of Crystal Angles at the Nanoscale (PELICAN)5, we compare nanocrystals in the same (pre)molar locations and show that misorientation increases with food hardness in extant and fossil non-human apes and monkeys. We compare misorientation...

Beyond the Pre‐Equilibrium Approximation: Consequences of Elementary Step (Ir)reversibility on the Mechanistic Interpretation of Tafel Slope

Tue, 16 Jun 2026 00:00:00 +0000

The relationship between electrochemical potential and reaction rate-or Tafel slope-is fundamental to the study of multi-step charge transfer reactions. However, despite its importance and ubiquitous use, Tafel slope is seldom interpreted outside of "cardinal" values. The mechanistic interpretation of cardinal Tafel slopes is predicated on the pre-equilibrium approximation (PEA): that the path between the (catalyst) resting state and rate-determining step is in equilibrium. This stringent approximation severely limits opportunities to elicit mechanistic information from electrochemical processes. In this Scientific Perspective, we broaden the existing framework for mechanistic interpretation of Tafel slope through a simple, universal equation that generally describes Tafel slope in terms of elementary-step symmetry factors and approach-to-equilibrium (i.e., approach to PEA accuracy). The predictiveness and mechanistic utility of these theoretical developments are showcased through...

Spectral analysis of chemical fluctuations of biomolecules in living cells.

Tue, 16 Jun 2026 00:00:00 +0000

Biomolecules suffering birth and death in living cells often exhibit non-exponential lifetime distributions. However, the chemical dynamics of these biomolecules cannot be described by conventional chemical kinetics or chemical master equations. Here, we present exact results for the mean, time correlation function, and power spectrum of the copy number of biomolecules in living cells, establishing their relationship to product creation dynamics and lifetime distributions. The correctness of these results is confirmed against accurate stochastic simulations. This work establishes the power spectrum of the copy number of biomolecules as a quantitative probe of their intracellular reaction dynamics.

A Lens into the Cu Nanograin by In Situ Vibrational Spectroscopy

Wed, 10 Jun 2026 00:00:00 +0000

Cu-based catalysts are uniquely capable of C-C coupling during electrochemical CO₂ reduction (CO₂R), yet further mechanistic understanding remains hampered by the lack of spectroscopically resolved descriptors that demonstrate how surface adsorbates emerge and evolve within their catalytic environment. Here, we correlate in situ surface-enhanced Raman spectroscopy (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRAS) to resolve the potential-dependent dynamics during CO₂R on Cu nanograin catalysts. By building on previous benchmarking of low overpotential performance and nanograin structural evolution, we offer a diagnostic framework linking vibrational signatures to catalytic function, unveiling which species appear, persist, and turnover as the electrified surface and interfacial environment evolve under bias. The onset of linear CO is marked below -0.45 V, coincident with persistent adsorbed *OH/*O domains beyond the CO₂R...

Reducing Flavin and Ubiquinone Headgroups with Silicon Nanowire Photocathodes

Fri, 5 Jun 2026 00:00:00 +0000

Photosynthetic biohybridsa structure composed of semiconducting electrodes and carbon dioxide-fixing autotrophs which can be energized by the electrodeoffer a promising platform for selective CO2 reduction. However, studying the charge-transfer mechanisms from the semiconductor to the cell proves challenging due to a variety of simultaneous processes. Therefore, to deconvolute the system to understand photoelectrochemical performance, we employ model systems composed of a subset of the electron-transfer pathway. Here, we photoelectrochemically reduced ubiquinone-0 (UQ0) and riboflavin (Rf) (the head groups of ubiquinone-8/10 and flavin mononucleotide/flavin adenine dinucleotide) using Pt-decorated n+p-silicon nanowires, a robust catalytic architecture. Under irradiation with 100 mW cm–2 red light (740 nm), UQ0 and Rf were reduced with onset potentials of 0.876 V vs the reversible hydrogen electrode (VRHE) and 0.691 VRHE, respectively. In addition, UQ0 achieved a maximum Faradaic...

An interactive machine learning platform for analyzing multi-particle coincidence data from cold target recoil ion momentum spectroscopy

Thu, 4 Jun 2026 00:00:00 +0000

We present SCULPT (Supervised Clustering and Uncovering Latent Patterns with Training), a comprehensive software platform for analyzing tabulated high-dimensional multi-particle coincidence data from Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) experiments. The software addresses critical challenges in modern momentum spectroscopy by integrating advanced machine learning techniques with physics-informed analysis in an interactive web-based environment. SCULPT implements uniform manifold approximation and projection for non-linear dimensionality reduction to reveal correlations in high-dimensional data. We also discuss potential extensions to deep autoencoders for feature learning and genetic programming for automated discovery of physically meaningful observables. A novel adaptive confidence scoring system provides quantitative reliability assessments by evaluating user-selected clustering quality metrics with predefined weights that reflect each metric's robustness....

Revealing ultrafast proton-transfer-mediated autoionization as a source of low-energy electrons in hydrogen-bonded systems

Thu, 4 Jun 2026 00:00:00 +0000

Ionizing radiation can trigger ultrafast proton transfer, a central mechanism in many chemical and biological functions, that in turn can enable or suppress electron relaxation processes and consequently cause abrupt changes in the reaction pathway. This study combines theory and experiment to probe ultrafast relaxation and dissociation in water dimers following inner- and outer-valence photoionization. By tracking electron and nuclear motion simultaneously, we reveal competing fragmentation pathways that produce low-energy electrons, which are key agents in radiation-induced chemistry, including DNA damage. While low-energy electrons are known to arise via intermolecular Coulombic decay, here we identify a faster relaxation mechanism gated by proton transfer following inner-valence ionization, which we call proton-transfer-mediated autoionization. Occurring within 10 femtoseconds, this process alters fragmentation outcomes, yielding either D3O+ + OD+ or D2O+ + D2O+, depending...

The Cascade Effectiveness of 3‑Terminal Tandem Photocathode Architectures as Applied to CO2 Reduction

Thu, 4 Jun 2026 00:00:00 +0000

Cascade catalysis for photoelectrochemical CO2 reduction (CO2R) decouples the overall reaction into sequential steps occurring on separately optimized catalysts (for example, Ag and Cu) between which an intermediate species such as CO is transferred. A 3-terminal tandem (3TT) photovoltaic architecture advantageously holds two different catalytic regions at different potentials under a single illumination source, but its overall efficiency is low. Using a stochastic reaction-diffusion model, we have examined 3TT photocathode design principles, focusing on the coupling of surface chemistry and transport of CO both inside the boundary layer and outward, into the bulk electrolyte. We find that ensuring that the lateral diffusion distance within the boundary layer is short compared to the boundary layer thickness and controlling bulk flow are key, with interdigitated designs showing an overall conversion efficiency improvement by 2 orders of magnitude compared to the side-by-side case...

Multi-modal characterization of nitrate reduction nano-catalysts with periodic strain distribution

Wed, 27 May 2026 00:00:00 +0000

Strain engineering serves as a pivotal strategy to optimize catalytic activity in electrocatalysis. However, the catalyst sizes under industrial conditions are usually large and even beyond nanometer regime. The critical methodological limitations on strain imaging of such catalysts with both large field of view and high spatial resolution obscure the mechanistic understanding of strain-performance correlations. Here, we present an optimized four-dimensional scanning transmission electron microscopy (4D-STEM) method to acquire strain mapping of both bulk and surface across particles up to 500 nm with 0.6 nm spatial resolution and 0.55% precision. We observe the ripple-like periodic strain coupled with elemental fluctuations inside a perovskite-type hydroxide CuCoSn(OH)6 and find it correlated to electrocatalytic nitrate reduction (NO3–RR) absorption energy to achieve the 92.6% Faradaic efficiency and long-term test over 1000 h at membrane electrode assembly (MEA) for ammonia electrosynthesis....

Tuneable electronic coupling in linked bis(cubane) cobalt-oxo clusters

Wed, 27 May 2026 00:00:00 +0000

A family of cobalt-oxo bis(cubane) complexes wherein each subunit is derived from the Co₄O₄ cubane, a known water oxidation catalyst, was synthesized. Both 4,4'-bipyrdine and pyrazine were demonstrated to serve as viable bridging ligands. Through an analysis of their half-wave splitting potentials, it was determined that pyrazine-bridged bis(cubane)s exhibit inter-cubane electronic coupling, and that this coupling may be tuned through ligand substitution. Electrostatic contributions to the half-wave splitting potentials were evaluated and found to result in "non-conformist" behavior related to the ion-pairing ability of the electrolytes.

One-Body Properties and Their Perturbative Accuracy with Aufbau Suppressed Coupled Cluster Theory

Wed, 27 May 2026 00:00:00 +0000

We derived and implemented the calculation of the one-body reduced density matrix for Aufbau suppressed coupled cluster theory, from which excited state natural orbitals and one-body properties, like atomic populations and dipole moments, are obtained. We utilized the natural orbitals to refine the ASCC solution for simple valence and Rydberg systems, exploring the process of repeatedly solving the ASCC equations in successive natural orbital bases to achieve independence from the starting molecular orbitals. For dipole moments in small molecules where high-level comparison data is available, we find that the accuracy of ASCC essentially matches that of linear response and equation-of-motion coupled cluster as long as care is taken to preserve the response's perturbative completeness.

Advanced pathways for hydrogen production: a collective view from a technical experts meeting

Thu, 14 May 2026 00:00:00 +0000

The current status of advanced water splitting pathways (using photoelectrochemical, biological and thermochemical platforms) toward viable technologies to produce renewable and sustainable hydrogen is assessed in a virtual international meeting. Hydrogen is an essential fuel and feedstock that can be produced in multiple ways to meet requirements for technological sectors that include energy storage, transportation, petroleum refining, and ammonia synthesis. To consider the future state of hydrogen manufacturing, a team of experts has assembled and examined three emerging hydrogen production technologies – photoelectrochemical, biological, and thermochemical. Each of these emerging technologies holds significant long-term potential for cost reduction while lowering industrial emissions associated with conventional methods of hydrogen manufacture ( e.g. , steam methane reforming) by using sunlight and renewable resources as primary sources of energy and feedstock, respectively....

The Interplay of Pauli Repulsion, Electrostatics, and Field Inhomogeneity for Blueshifting and Redshifting Vibrational Probe Molecules

Thu, 14 May 2026 00:00:00 +0000

Many molecules' vibrational frequencies are sensitive to intermolecular electric fields, enabling them to probe the field in complex molecular environments. However, it is often unclear whether the probe is responding to the local electric field or other types of intermolecular interactions, inhibiting interpretation of the frequency and effectiveness as probes. This is especially true for molecules whose vibrational frequencies blueshift instead of the more typical redshift in hydrogen bonding configurations. Here, we computationally investigate the causes of redshifting versus blueshifting over a range of vibrational reporters. First, we apply adiabatic energy decomposition analysis to a paradigmatic set of probes, finding that redshifting only occurs when electrostatic interactions are strong enough to overcome the dominant and large blueshifting contribution of Pauli repulsion. Furthermore, we demonstrate that field inhomogeneity can further shift the frequency of many probes...

Navigating the research landscape for hyper-NA EUV lithography and future patterning technologies

Wed, 29 Apr 2026 00:00:00 +0000

Hyper-Numerical Aperture (Hyper-NA) Extreme Ultraviolet (EUV) lithography is gathering growing support as the technology of choice to sustain the dimensional scaling trajectory of Moore's Law. This transition, which targets resolution down to 5 nm, necessitates several research advances across several key lithography areas, such as patterning materials, imaging with polarization control, and the optimization of the mask structure. In this paper, we briefly review the historical role of the government-industrial partnerships enabling Center for X-Ray Optics (CXRO) pathfinding research for prior EUV lithography generations. We also highlight the role of the Department of Energy's Energy Frontier Research Center (EFRC) on High-Precision Patterning Science (CHiPPS) as a critical initiative to fundamentally address the pervasive stochastic challenges in materials science that limit the RLS (Resolution, Sensitivity, Line Edge Roughness) tradeoff, charting a path toward the Angstrom...

Electronic Structure Tuning of Lanthanidocene Photocatalysts for C–F Bond Cleavage