Chemphyschem最新文献

Two-dimensional ferromagnets are highly attractive for spintronic applications and chromium-telluride compounds form one of the most diverse families in this field. While the layered 1T-CrTe₂ has been studied extensively for its high Curie temperature, strong anisotropy, and large magnetic moments, its parent compound KCrTe₂ has received almost no systematic attention. Large crystals of KCrTe₂ were grown by solid-state methods. Large 1T-CrTe₂ crystals were obtained via deintercalation of K from KCrTe₂. KCrTe₂ exhibited an antiferromagnetic transition around 87 K, which resides between LiCrTe₂ and NaCrTe₂. The chemical process from KCrTe₂ to 1T-CrTe₂ was studied by static studies. The complete removal of K within KCrTe₂ helps make 1T-CrTe₂ easy fabrication of large thin flakes (the easy-peel 1T-CrTe₂), which were studied using ferromagnetic resonance spectroscopy (FMR). FMR was employed to study the magnetization dynamics of 1T-CrTe₂ crystals, which verified that 1T-CrTe₂ crystals exhibited ferromagnetic response at room temperature.

Designer solvents (DSs), particularly room-temperature ionic liquids (RTIL) and deep eutectic solvents (DES), have emerged as promising alternatives for capturing volatile organic compounds (VOC), addressing the limitations of conventional mitigation strategies. The tunability of DSs-achieved via functional group modification, hydrogen bond donor-acceptor pairing, and incorporation of supramolecular additives-was found to be key in optimizing VOC solubility and retention. Beyond bulk absorption, DSs have also been shown to enhance VOC uptake in porous hybrid materials, underscoring their role in integrated capture systems. Despite these advances, molecular-level understanding of VOC-solvent interactions remains fragmented, limiting predictive design. In this perspective, we summarize key experimental and computational insights that have advanced the molecular understanding of VOC absorption in DSs. Drawing upon our past molecular dynamics (MD) studies and related literature, we highlight how interfacial structuring, solvation thermodynamics, and donor-acceptor chemistry dictate the efficiency of RTIL and DES. Comparative analysis between these solvent families provides a framework for identifying optimal VOC-specific DSs. We conclude by outlining emerging research directions where synergistic experimental-computational approaches can accelerate the rational development of green solvent technologies for air-quality management and emission control.

A novel potentiometric multisensor system was developed for the simultaneous determination of chloride, potassium, sodium, and calcium ions in human body fluids. The device consists of an integrated platform comprising four ion-selective paste electrodes with renewable sensing surfaces, enabling repeated use and stable performance. Conditioning, calibration, and analysis were performed in mixed solutions containing all target ions, allowing simultaneous determination of calibration curves and significantly reducing analysis time. The multisensor exhibited near-Nernstian slopes, wide linear concentration ranges, high capacitance, and low potential drift, ensuring reliable operation within the physiological pH range. The system was successfully applied to diluted samples of artificial saliva, sweat, and blood serum of biological origin, yielding recovery values between 97% and 108%, thus confirming its accuracy and practical applicability. This work presents an efficient potentiometric platform for simultaneous electrolyte monitoring in complex biological matrices.

Trimethylamine N-oxide (TMAO) is an osmolyte whose role in protein aggregation is poorly understood. We investigate the molecular basis of the phenomenon where TMAO increases the denaturation temperature of lysozyme while simultaneously inducing its irreversible aggregation. Using density functional theory (DFT), we analyzed the thermodynamics of TMAO's interaction with protein fragments exposed during denaturation. The results indicate that TMAO forms energetically favorable interactions with numerous fragments, particularly with the peptide backbone and the side chains of serine, threonine, tyrosine, and lysine, in contrast to acidic residues. This preferential binding stabilizes the denatured state, which facilitates interchain contacts and initiates aggregation. These findings provide a molecular explanation for the proaggregating role of TMAO toward denatured lysozyme.

About 20 years ago, it was observed that chemical reactions in dispersed aqueous systems tend to accelerate compared to the same reactions in bulk solutions. Subsequently, similar acceleration was observed in other interface-rich systems, such as water microdroplets. Studying these processes has become a topic of enormous interest due to their numerous potential applications. From a theoretical point of view, their study is also extremely attractive, as the experimental data are not adequately explained by standard approaches and point to unique phenomena that are not yet well understood. Recent studies emphasize the role of electric fields associated with the broken symmetry and the unique solvation properties of interfaces. The aim of this review is to provide a brief overview of our own research, placing it in the context of other important findings described in the literature, and to clarify some points about the different aspects related to electrostatics at aqueous interfaces. Finally, we suggest a mechanism to explain the apparent role of the interface as an electron donor catalyst. We hope that this article will be useful to colleagues working in this field and to those who are simply interested in it.

Two-dimensional (2D) metal halide perovskites have great potential for applications in photodetectors (PDs), but there are still many challenges in the simple and efficient construction of their heterojunctions and the realization of excellent self-powered functions. In this work, we employ a simple ion exchange strategy to directly grow a 2D PEA₂PbI₄ layer on the PEA₂PbBr₄ film using a simple and easily implemented solution method. By precisely controlling the concentration of the phenethylamine hydroiodide/isopropanol (PEAI/IPA) solution, high-quality PEA₂PbBr₄/PEA₂PbI₄ heterojunction films are obtained. Furthermore, the self-powered PDs assembled based on the 2D/2D PEA₂PbBr₄/PEA₂PbI₄ heterojunction exhibit outstanding self-powered photoelectric performance across the UV-visible spectrum, with a responsivity of 75.6 mA/W and a detectivity of 4.16 × 10¹¹ Jones, respectively, which are more than five times that of the PEA₂PbBr₄ photodetector. In particular, this heterojunction photodetector exhibits excellent long-term self-powered photoelectric switching characteristics and environmental stability.

The photochemistry of a commercial sunflower sprout extract was compared to that of pure chlorogenic acid (3-O-caffeoylquinic acid), a key photoprotective species found in the extract. Steady-state and time-resolved spectroscopy experiments revealed virtually equivalent photodynamics between aqueous solutions of the sunflower extract and chlorogenic acid, namely ∼5 picosecond nonradiative deactivation following UV photoexcitation. For chlorogenic acid, this nonradiative deactivation is achieved by relaxation through a conical intersection, mediated through rotation around the caffeoyl CC double bond. These photophysical similarities tentatively justify the use of the unpurified sprout extract for use in UV photoprotective formulations and demonstrate that the environmental complexity conferred by the presence of other phytochemical constituents in the extract does not impede the relaxation mechanism of chlorogenic acid.

Till date, porphyrin molecules are best available photosensitizers (PS) for cancer therapy with good singlet oxygen generation (SOG) capability; however, with minimal fluorescence. Suitable coupling of PS with the plasmonic nanoparticle may result into enhanced fluorescence and SOG, which is attractive for image-guided photodynamic therapy (PDT). Here, Tetrakis(2,4,6-trihydroxyphenyl)porphyrin (THPP) molecules and gold nanoparticles (AuNPs) of two different sizes are synthesized and subsequently conjugated via L-cysteine and introduced as novel plasmon-enhanced nano-PS. Upon excitation at 418 nm, simultaneous enhancement in fluorescence and SOG was achieved for hybrid nanostructure, when compared with fluorescence intensity (FI) and SOG of only THPP molecule in absence of AuNPs. Among two different sizes of AuNPs, more enhancement is observed with average diameter of 25 nm, whereas 45 nm showed less enhancement. The possible mechanism is ascribed to local electric field enhancement by the AuNPs, where overlap of Q-band of THPP, localized surface plasmon resonance peak of AuNPs, and the excitation wavelength is the important factor. We witness that enhancement in fluorescence is accompanied with no reduction in faster lifetime component of THPP. Overall, the work shows a rational approach to design PS-metal configurations with desired emissive properties with higher SOG for useful PDT approach.

Isocyanides as hydrogen-bond acceptors are characterized using jet-cooled Fourier transform infrared spectroscopy for the first time. The hydrogen-bonded structures of tert-butyl isocyanide (t-BuNC) and its constitutional isomer pivalonitrile (t-BuCN) with a single H₂O or tert-butyl alcohol (t-BuOH) molecule are analyzed. The most stable monohydrate structures differ markedly: t-BuNC adopts a classical σ-type hydrogen bond, whereas t-BuCN favors a dispersion-stabilized orthogonal π-type arrangement. Substitution of H₂O with the more polarizable t-BuOH enhances dispersion interaction between the molecules and drives both complexes toward π-type binding motifs. These findings highlight the balance between dispersive and electrostatic interactions in governing noncovalent binding preferences.

Chalcogen bond (ChB) catalysis is a significant strategy in organocatalysis due to its modifiable polarity, notable directionality, and the flexibility that aids both binding and dissociation. As an important benchmark reaction, the transfer hydrogenation of quinoline (QNL) is widely used to evaluate the catalytic performance and to explore the relationship between the structure and activity of catalysts. In this work, density functional theory calculations are employed to elucidate the mechanism of the ChB-catalyzed transfer hydrogenation of QNL using Hantzsch ester (HEH) as the hydrogen source. Analysis of the transition state properties in the rate-determining step reveals that the σ-hole of ChB catalysts interacts with the nitrogen lone pairs of HEH, accompanied by charge transfer and rearrangement processes occurring throughout the reaction. Energy decomposition analysis (EDA), together with Natural Bond Orbital (NBO) and quantum theory of atoms in molecules (QTAIM) analyses, reveals that polarization effects predominantly stabilize the chalcogen bond (ChB), thereby lowering the reaction energy barriers. This insight provides a foundation for the rational design of new ChB catalysts.