Chemphyschem最新文献

Lignin valorization is restricted by the stability of its methoxy groups, creating a critical need for efficient demethylation strategies. Here, density functional theory (DFT) is employed to dissect the mechanistic pathways of demethylation in lignin model compounds, guaiacol and syringol, using protic ionic liquids (PILs) that act as both solvent and catalyst. Conductor-like Screening Model for Real Solvents (COSMO-RS) analysis identifies monoethanolammonium acetate ([MEOA][Ace]) as the most promising medium, attributed to its strong hydrogen bonding network and solvation ability. By integrating implicit and explicit solvation models, it is revealed that an acid-catalyzed hydrolytic mechanism governs demethylation, with PILs stabilizing crucial transition states and intermediates. Complementary electronic structure evaluations, including highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO-LUMO) gap analysis, charge distribution, and electrostatic potential mapping, demonstrate how PILs lower energetic barriers and enhance reactivity. To simulate realistic environments, this study is extended to lignin dimer complexes with varying water content, uncovering how water-bridged solvation reverses demethylation preference from guaiacyl to syringyl units. This mechanistic shift aligns with experimental observations showing faster S-unit reactivity in hydrated systems. Together, these findings provide atomic-level insight into lignin demethylation dynamics and highlight how tuning acid concentration in PILs can accelerate kinetics, enabling a rational pathway toward next-generation biomass conversion technologies.

Calcium boranate (Ca(BH₄)₂) is synthesized using wet chemistry metathesis reactions resulting in mixtures of both α- and β-Ca(BH₄)₂, with the β phase being the main component. The drying procedure reveals high kinetic stability of the high temperature β polymorph, which is in contrast to the expectations based on the literature. The molar heat capacity function of β-Ca(BH₄)₂ is determined between 2 and 525 K using different calorimeters, a Physical Property Measurement System applying the relaxation method in the low temperature range and a Calvet-DSC for the high temperature range. From these values the absolute standard entropy at 298.15 K for β-Ca(BH₄)₂ is calculated as S^°(298.15 K) = (117.4 ± 4.1) J mol⁻¹ K⁻¹. Taking the value of the enthalpy of formation from the literature, the Gibbs energy functions are calculated and the decomposition and rehydrogenation behavior of the compound is discussed.

In recent years, innovative methods for synthesizing borophene have been developed, enabling the production of large-area borophene sheets that can be transferred to various substrates. Experimental studies have successfully tackled oxidation stability issues of borophene, yielding promising results. These advancements have facilitated the use of borophene in the fabrication of electrical, optical, and electrochemical devices, with recent reports highlighting significant progress in these areas. This review focuses on novel synthesis methods for producing large-area borophene and explores techniques for fabricating its devices. Additionally, the practical applications of borophene in optics, electronics, and electrochemistry compared to other 2D materials are being focused. Given the unique and unparalleled properties of borophene, it has emerged as a viable alternative to graphene in these fields. This article reviews experimental studies where borophene has demonstrated significant success in various applications compared to other 2D materials. While previous reviews have primarily addressed some properties and potential applications of borophene, recent advancements have validated several predictions, which in this article is being explored. This focused review to effectively outline future research directions for borophene applications is aimed.

The accurate description of metal–water interfaces is essential for understanding processes in heterogeneous catalysis, electrochemistry, and surface science. Capturing the delicate balance between electrostatic and charge-transfer interactions in these systems, while efficiently sampling configurations to locate minima or approximate thermodynamic ensembles, requires electronic-structure methods that are both accurate and computationally efficient. Density functional tight-binding methods have the potential to strike the right balance, and here we demonstrate how systematic parameter optimization within the GFN1-xTB framework improves the description of water–metal interactions. Using previously published reference data for five metals (Cu, Ag, Au, Pd, Pt) and their (100) and (111) facets, we explore various adsorption sites, orientations, and distances. Sobol sensitivity analysis identifies the most influential parameters for each system, which are then optimized to minimize errors in adsorption energies. This targeted optimization yields substantial accuracy gains, reducing root-mean-square errors by approximately 20–60%. The modified method provides reliable predictions for catalytic studies where the default parameterization can fail qualitatively. However, such improvements come at the cost of reduced transferability across systems and properties, emphasizing that parameter optimization must be carefully tailored to the specific chemical context.

NO hydrogenation not only produces NH₃ but also reduces NO emissions. The high cost associated with high-purity H₂ can be circumvented by using H₂O as a hydrogen source. Herein, the first principles calculations show that Aluminum (Al) facilitates the hydrogenation of NO and the formation of NH₃ via thermal catalysis. The energy barriers on Al(111) and Al(100) are 0.45 eV and 0.12 eV, respectively. After NH₃ desorption, the energy barrier for NO decomposition on the O* and *OH covered surface is only 0.33 eV. This NO-based, H₂O-mediated NH₃ synthesis not only mitigates environmental pollution but also proceeds under relatively mild conditions. This study also enriches the application of main group metal in heterogeneous catalysis.

Hybrid material architectures emerge as a transformative approach to enhance the performance of gas sensors. This study reports a novel room-temperature ammonia (NH₃) sensor based on a porous zinc oxide nanoflakes (ZnOP) and polymer-dispersed cholesteric liquid crystal (PDCLC) composite. The hybrid design integrates the high surface area and mesoporous architecture of ZnO with the functional interfacial properties of PDCLC, yielding a material system that excels in both response and selectivity. The sensor demonstrates exceptional performance metrics, including a broad detection range (1–100 ppm), a low detection limit of 2.61 ppm, and rapid response and recovery times of 5 and 18 s, respectively. Notably, the sensor exhibits superior selectivity toward NH₃ over other volatile organic gases, attributed to the tailored interaction between ammonia molecules and the PDCLC matrix. Moreover, the synergistic interplay between ZnOP and PDCLC enhances electron transfer dynamics, further improving sensing efficiency. This work underscores the potential of porous ZnOP/PDCLC hybrids as advanced materials for ppm-level NH₃ detection and establishes a robust platform for designing high-performance gas sensors operable at room temperature.

The Cover Feature shows how the interface of AOT reverse micelles acts as a molecular factory, where strongly confined hydration water becomes highly nucleophilic and drives the hydrolysis of dimethyl carbonate into methanol, even in the absence of added water. More information can be found in the Research Article by N. M. Correa and co-workers (DOI: 10.1002/cphc.202500376).

Self-assembled molecules (SAMs) have been widely used as hole-selective layers for inverted perovskite solar cells. In this work, eight hole-selective compounds containing different acidic anchoring groups are designed. Their anchoring effects on the typical indium tin oxide (ITO) surface, including both absorption structure and electron states, are systematically studied using the first-principles calculation method based on density functional theory. Among the eight anchoring groups, silicic acid, cyanoacetic acid, cyanophosphoric acid, and phosphoric acid are the strongest in the absorption ability, and it is found that an increase in the number of dehydrogenations of the anchoring groups leads to an increase in the adsorption capacity of SAMs. In addition, the adsorption of SAMs can also cause the change of ITO's work function, providing a potential strategy to modify the work function of transparent conductive oxide substrate by anchoring group engineering. The Ab Initio Molecular Dynamics simulation at high temperature reveals that the silicic acid and phosphoric acid anchoring groups have the best thermal stability. Study of SAMs/FAPbI₃ adsorption system reveals that cyanoacetic acid anchoring group has the largest adsorption energy. This work shows the great potential of precisely designed self-assembled molecules for high-performance perovskite solar cells.

Cyclopentadienyl–lithium complexes are fundamental to organometallic chemistry, with broad applications in catalysis, materials science, and synthetic chemistry, powering advances in catalysis, materials design, and synthesis. To engineer better materials, a deeper grasp of how Cp ligands bond with lithium atoms is required. In this study, density functional theory, natural bond orbital analysis, and natural energy decomposition analysis are employed to investigate the bonding interactions in Cp_nLi_n (n = 1–6) and characterize their structural and electron properties. The results show that neutral complexes form significantly stronger CpLi bonds, with interaction energies ranging from −175.22 to −184.52 kcal mol⁻¹, compared to their anionic counterparts. NEDA demonstrates that electrostatic and charge transfer contributions are the primary stabilizing forces, while steric and core repulsions introduce minor destabilization. Second−order donor−acceptor stabilization energies (E(2)) further subtle but stabilizing contributions, in neutral complexes, primarily involving σ(CH) bonds coordinated to lithium atoms. These insights into bonding and stability offer a strategic foundation for designing materials with tailored electronic and structural properties. Future studies should expand to larger clusters, alternative charge states, and functionalized ligands to unlock new reactivity and behaviors.

The Front Cover illustrates how organic mixed ionic-electronic conductors (OMIECs) serve as a critical bridge between ionic and electronic signaling. The Review by T. E. Gartner III, E. Reichmanis and co-workers (DOI: 10.1002/cphc.202500403) highlights the intrinsic property of OMIECs to accommodate ionic charge uptake from an electrolyte while simultaneously conducting electronic charge carriers along their conjugated backbones. This dual-conduction capability seamlessly connects two disparate signaling worlds, enabling the development of advanced bioelectronic applications.