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Non-enzymatic electrochemical blood glucose sensors often suffer from issues such as requiring an alkaline environment, limited monitoring range, and poor anti-interference properties. Carbon substrates have been demonstrated to improve the performance of non-enzymatic sensors, but complex and energy-consuming manufacturing processes restrict their use. Herein, a simple and green approach for the preparation of 3D porous Au/Au-Pt networks (PAAPNs) is proposed using tissue paper for recycling as the nanomaterial substrate to deposit Au-Pt bimetallic nanoparticles. The unique structure of the PAAPNs sensor allows for low-potential operation (-1.0 V) with a wide monitoring range (-0.25 to 36 mM) in a neutral environment. Moreover, the sensor exhibited excellent selectivity (<10% response of interference) even without the use of an anti-interference outer membrane. Further investigation using density functional theory (DFT) simulation revealed the synergistic effect between Au and Pt in promoting glucose oxidation. Overall, this work provides a simple and low-carbon footprint method for creating carbon substrates from tissue paper for recycling, offering new opportunities for fabricating novel value-added nanomaterials for medical sensing applications. [ABSTRACT FROM AUTHOR]

It is significant to develop low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) via electrochemical water splitting. Herein, we constructed P-doped NiCo2S4 nanowire arrays on carbon fiber paper (NiCo2S4−xPx/CFP) as a HER electrocatalyst in both acidic and alkaline media. Benefitting from P doping into NiCo2S4, the as-prepared NiCo2S4−xPx/CFP exhibits low HER overpotentials of 80 and 132 mV in acidic and alkaline media at a cathodic current density of 10 mA cm−2, respectively, which are far superior to counterparts of NiCo2S4 nanowire arrays on the carbon fiber paper (NiCo2S4/CFP). Meanwhile, the NiCo2S4−xPx/CFP presents excellent HER stability of 20 hours in acidic and alkaline media. From the results of density functional theory calculations, P doping can not only optimize the hydrogen adsorption energetics on each kind of atomic site of catalysts, but also strengthen the H2O molecule binding ability on the catalyst surface for the alkaline HER and favor kinetics of hydrogen adsorption and H2 formation on the catalyst surface for the acidic HER, eventually improving overall HER performances. The investigation of the HER mechanism modulated by P doping in our work offers novel inspiration to develop highly efficient ternary metal sulfides for the HER. [ABSTRACT FROM AUTHOR]

This paper explores the findings on the structures and physicochemical properties of titanium-oxo complexes (TOCs) stabilized by 9-hydroxy-9-fluorenecarboxylate ligands. Two complexes, with the overall formulas [Ti4O(OiPr)10(O3C14H8)2] (1) and [Ti6O4(OiPr)2(O3C14H8)4(O2CEt)6] (2), have been synthesized. The structures of the isolated crystals (1 and 2) were determined using single-crystal X-ray diffraction. Molecular structure analysis of the crystals also employed vibrational spectroscopic techniques (IR and Raman), UV--Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and powder X-ray diffraction (XRD). Density functional theory (DFT) was utilized to elucidate the electronic structures of these complexes. Furthermore, the theoretical charge distribution in 1 and 2 and their reactivity were calculated. The results of these investigations suggest that the reactivity of 2 is significantly greater than that of 1. [ABSTRACT FROM AUTHOR]

In this paper, the geometric configuration, electronic properties, and optical characteristics of an InS/GaTe heterojunction have been computed using the foundational principles of density functional theory. The analysis indicates that when the interlayer distance is 3.88 Å, the binding energy is the most negative, indicating that the structure is the most stable. The bandgap of the two monolayers is larger than that of the heterojunction, which makes the photogenerated electrons of the heterojunction more easily excited. The InS/GaTe heterojunction is a type-II heterojunction that enhances the efficient dissociation of electron–hole pairs. In addition, the InS/GaTe heterojunction demonstrates strong absorption of ultraviolet light, rendering it suitable for applications in ultraviolet detectors and related fields. Furthermore, the bandgap electron transfer direction of the InS/GaTe heterojunction can be controlled by applying electrical force and mechanical pressure. The optical absorption coefficient of the InS/GaTe heterojunction can be adjusted to modify its optical properties. Finally, the possible future applications of the InS/GaTe heterojunction are discussed. [ABSTRACT FROM AUTHOR]

This research paper investigates the electrocatalytic mechanisms and ultra-trace detection abilities of uranyl ions (UO22+) using palladium nanoparticles (PdNPs) electrodeposited in deep eutectic solvents (DESs). The unique properties of DESs, such as their adjustable viscosity and ionic conductivity, offer an advantageous and environmentally friendly medium for Pd nanoparticle electrodeposition, resulting in highly active and stable electrocatalysts. Various characterization techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), were used to examine the morphology, size distribution, and crystallographic structure of the Pd nanoparticles. Electrochemical tests revealed that the Pd-modified electrodes show exceptional electrocatalytic activity and current sensitivity towards uranyl ions, with detection limits as low as 3.4 nM. Density functional theory (DFT) calculations were conducted to elucidate the mechanism of the electrocatalytic reduction of UO22+ by the PdNPs, providing a plausible explanation for the high sensitivity of PdNPs in detecting uranyl ions based on the calculated structural parameters and reaction energetics. This study underscores the potential of Pd nanoparticles electrodeposited in DESs as a promising method for sensitive uranyl ion detection, contributing to advancements in environmental monitoring and nuclear safety. [ABSTRACT FROM AUTHOR]

In this paper, three different Zn(II) complexes with (E)-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL2](BF4)2, while complexes 2 [ZnL(NCO)2] and 3 [ZnL(N3)2] form penta-coordinated geometry. Density functional theory (DFT) calculations were performed to enhance our understanding of the structures of the synthesized complexes and the cytotoxic activity of the complexes was tested against five human cancer cell lines (HeLa, A549, MDA-MB-231, K562, LS 174T) and normal human fibroblasts MRC-5. Additionally, antibacterial and antifungal activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two fungal strains, and a yeast strain. It is noteworthy that all three complexes show selective antifungal activity comparable to that of amphotericin B. Molecular docking analysis predicted that geranylgeranyl pyrophosphate synthase, an enzyme essential for sterol biosynthesis, is the most likely target for inhibition by the tested complexes. [ABSTRACT FROM AUTHOR]

This paper evaluates the effect of different synthesis conditions on the structural properties of the porous metal–organic frameworks MIL-53(Al) produced by the microwave method at different reaction temperatures (120, 150, and 180 °C) and times (30, 180 min). The morphologies, chemical contents and crystal structures of the synthesized samples were determined by the SEM-EDS and XRD methods, respectively. The structural properties of MIL-53(Al)s were analysed according to isotherm data obtained from nitrogen gas adsorption by applying the Brunauer–Emmett–Teller (BET), Langmuir, Dubinin–Radushkevich (DR), t-plot, Barrett–Joyner–Halenda (BJH) and quenched solid density functional theory (QSDFT) methods, as well as the new numerical clustering-based adsorption analysis (LBET) method, which is a unique numerical method that provides advanced assessment for porous structures. The LBET analysis showed that the MIL-53(Al) sample at a reaction temperature of 180 °C for 30 min has the best adsorption properties, with the highest volume of the first adsorbed layer and the highest value of the energy parameter for higher layers. Due the LBET method, it was possible to evaluate the porous structure of the MIL-53(Al) samples with high precision and reliability, and thus to determine the precise influence of the conditions of their preparation on the formation of their structure. In turn, based on the shapes of the pore size distributions (PSD), the materials analysed have very similar PSD, with only the MIL-35(AL)S1 sample having a significantly lower PSD height. In conclusion, attention was paid to the necessity of complex evaluation of adsorbent properties, taking into account not only their adsorption properties but also their mechanical and functional properties, as well as production costs and the impact of adsorbent production and utilization on the environment. [ABSTRACT FROM AUTHOR]

The strong metal–support interactions (SMSI) between metal and its support have been regarded as a valid approach to enhance the catalytic performance; however, the extent to which exploration of electronic state regulation affects catalytic performance of alcohol oxidation reactions (AOR) has been rarely reported. In this paper, PdAg nanoparticles loaded on a N-doped carbon substrate with controlled nitrogen content (PdAg@NxC, x representing the nitrogen contents) was synthesized through a seeded synthesis strategy for alkaline AOR. Results show that the electronic state of PdAg nanoparticles was significantly modified after nitrogen doping in the carbon support. Experimental and theoretical results indicate that with increasing nitrogen content, the degree of electronic state regulation becomes increasingly significant. Density functional theory (DFT) calculations suggest that the increased degree of SMSI promotes OH* adsorption on the PdAg surface and weakens the binding between catalyst and CO*. As a result, the PdAg@N15.3C with the highest N content exhibits excellent AOR performance, achieving a MA/SA of 10.8 A mgPd−1/13.2 mA cm−2 and 3.8 A mgPd−1/4.7 mA cm−2 on the EOR and MOR, respectively. Moreover, due to the changes in the adsorption energy of key intermediates on PdAg nanoparticles, the onset oxidation potential of PdAg@N15.3C shows a negative shift of 180 mV compared to PdAg@C as revealed by CO stripping analysis, signifying an increase in the CO tolerance. Our study demonstrates the influence of the SMSI effect between the active center and the support on the catalytic performance for AOR and presents a pathway to achieve high AOR performance through SMSI engineering. [ABSTRACT FROM AUTHOR]

We present in this paper the stability of SWCNT hybrid systems with Py molecules. vdW type interactions are therefore the main interaction mechanism between encapsulated molecules and nanotubes, and the simplest model to describe these interactions is the Lennard-Jones potential. We have therefore performed energy minimization calculations on hybrid SWCNTs in a very wide range of diameters and of all chirality using the Lennard-Jones potential. The structure of the carbon nanotube is obtained from the winding of graphene on itself to form a hollow cylinder described by the pair of integers (n, m) entirely determining its structural characteristics, while the optimization of the geometry of the Py molecule is obtained by SIESTA using the exchange–correlation functional LDA. After minimisation, an approach that combines density functional theory, molecular mechanics, bond polarizability model, and spectral moment's method has been used to compute Raman spectra. Two types of vibration modes of SWCNTs attract our attention. Initially, the modifications of the modes of Py after encapsulation will be analyzed. In the following discussion, we examine how the vibrational properties of single-walled carbon nanotubes (SWCNTs) are affected by encapsulation, specifically in relation to the RBM and tangential modes. Our analysis of the Raman active modes supports the notion that the structural integrity of the SWCNTs remains intact and indicates the occurrence of a charge transfer between the Py molecules and SWCNTs. This charge transfer depends on the geometric position of Py in the SWCNT. [ABSTRACT FROM AUTHOR]

In this paper, three different Zn(II) complexes with ( E )-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)- N , N , N -trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL 2 ](BF 4 ) 2 , while complexes 2 [ZnL(NCO) 2 ] and 3 [ZnL(N 3 ) 2 ] form penta-coordinated geometry. Density functional theory (DFT) calculations were performed to enhance our understanding of the structures of the synthesized complexes and the cytotoxic activity of the complexes was tested against five human cancer cell lines (HeLa, A549, MDA-MB-231, K562, LS 174T) and normal human fibroblasts MRC-5. Additionally, antibacterial and antifungal activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two fungal strains, and a yeast strain. It is noteworthy that all three complexes show selective antifungal activity comparable to that of amphotericin B. Molecular docking analysis predicted that geranylgeranyl pyrophosphate synthase, an enzyme essential for sterol biosynthesis, is the most likely target for inhibition by the tested complexes.

As a promising candidate to replace lithium-ion batteries, rechargeable aqueous zinc ion batteries (AZIB) are receiving increasing attention due their high energy density, high safety, low cost and environmental friendliness. In this study, metal ions may be introduced into the interlayer gap of layered vanadium oxide nanobelts through a one-step hydrothermal process, without changing their original structure. Moreover, we have demonstrated by density functional theory computations that Mn metal ions not only serve as structural pillars but also enhance the conductivity of MnxVO2·0.2H2O, facilitating the migration of Zn ions. As a result, the electrochemical performance of MnxVO2·0.2H2O as an AZIB cathode has significantly improved; after 100 cycles at 0.5 A g−1, it exhibits a high reversible capacity of 350 mA h g−1. With a high current density of 5 A g−1, the initial capacity can still reach 295 mA h g−1. This paper suggests an effective method to maximize the efficiency of AZIB electrode materials. [ABSTRACT FROM AUTHOR]

High entropy materials (HEM) have been attracting much attention as emerging catalysts for electrochemical water splitting. HEM catalysts have unique properties such as an interesting cocktail effect, broad design space, customizable electronic structure, and excellent entropy stabilization effect compared with single-digit catalysts. This paper provides a comprehensive overview of the use of HEM as a catalyst for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and water splitting. HEM design strategies including phase structure modulation, defect engineering, electrode configuration engineering, and computational aids are discussed to develop HEM catalysts with high performance and stability. In particular, the importance of density functional theory, high-throughput screening techniques, and machine learning for the discovery and design of HEM catalysts is emphasized. Finally, the challenges and imminent difficulties are prospected, and the corresponding strategies to deal with these challenges are put forward to promote the development of HEM catalysts in the field of electrochemical water splitting. [ABSTRACT FROM AUTHOR]

The development of efficient non-noble metal electrocatalysts for the oxygen evolution reaction (OER) under acidic conditions remains a critical challenge. Herein, we report a N-doped carbonaceous component-engineered Co3O4 (NCEC) catalyst synthesized via the sol-gel method. Dopamine hydrochloride (DA)-derived nitrogen-doped carbonaceous components were found to boost the OER performance of Co3O4. The optimized catalyst can reach an overpotential as low as 330 mV in 1 M H2SO4 at a current density of 10 mA cm-2 and maintains a good long-term stability of 60 hours. In particular, we found that the thermodynamic overpotential was inversely proportional to the content of oxidized N and pyridinic N, whereas it was directly proportional to the pyrrolic-N content. Our experiments and density functional theory (DFT) calculations confirm that the optimized catalyst exhibits enhanced charge transfer and the oxidized N species on Co3O4 is responsible for the high catalytic activity. Our study suggests that the performance of NCEC in acidic media can be further optimized by enhancing the content of oxidized N species. [ABSTRACT FROM AUTHOR]

Calix[8]arene has been used as a promising type of macrocyclic ligand for the construction of multinuclear metal-oxo clusters (MOCs), but not for zirconium/hafnium-oxo clusters (Zr/HfOCs). In this paper, we report the first series of ZrOCs (HfOCs) based on calix[8]arene: Zr4, Zr8, Hf4, and Hf8. Zr8/Hf8 has a rhombohedral conformation and can be regarded as a derivative of the octahedral Zr6 cluster. Remarkably, I2 adsorption experiments indicate that Zr4 (Zr8) adsorbs much faster than Hf4 (Hf8). Density functional theory (DFT) calculations show that metallic Zr atoms interact more strongly with I2 than metallic Hf atoms. The successful application of calix[8]arene for the synthesis of well-defined ZrOCs (HfOCs) shows a bright future for MOCs protected by macrocyclic ligands. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are a class of multimodal three-dimensional materials that have been applied as luminescent sensors for ions and molecules existing in water bodies. Herein, a new Cd(II)-based MOF, [H2bpd]2[Cd3(L)2] (1) (bpd = bis(pyridin-4-ylmethyl)propane-1,3-diamine; H5L = 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid), was synthesized and characterized. Single crystal X-ray analysis revealed that 1 is anionic in nature and exhibits a flu-type topology with the point symbol (412·612·84)(46)2. This MOF was used as a turn-off photoluminescent sensor to detect Fe3+ and CrO42− by forming 1@Fe3+ and 1@CrO42− complexes, respectively. In the case of the Fe3+ cation, 1 displayed a KSV of 0.01763 and limit of detection (LOD) of 5.315 ppm, while for the chromate anion, it exhibited a KSV of 0.07338 and limit of detection of 1.277 ppm. Interestingly, the emissive response of 1 was restored upon the addition of hydroquinone (hyd) and 4-hydroxybenzoic acid (hyd acid) (turn-on) due to the competitive formation of hyd@Fe3+ or hyd acid@CrO42−, respectively, with the concomitant release of 1. The sensing properties of 1 and the recovery of its emission response in the presence of hyd and hyd acid were evaluated with the help of Hirshfeld surface and density functional theory analyses, respectively. The recovery of the emission property of 1 on the addition of hyd and hyd acid over other antioxidants arises because of their larger EHOMO and relatively less steric hindrance than those of the other oxidants employed in this study. [ABSTRACT FROM AUTHOR]

Utilizing density functional theory (DFT) calculations, we systematically explored the potential of the defective NiCl2 nanosheet with Cl vacancies (VCl-NiCl2) as a gas sensor for the detection of H2, CO2, NO, O2, H2O, CO, and NO2 gases. The results revealed that NO, O2, H2O, CO, and NO2 can be chemisorbed on Ni sites around Cl vacancies with significant adsorption energy (−0.66 to −1.83 eV), accompanied by a considerable amount of charge transfer and an obvious change in the electronic and magnetic properties of the VCl-NiCl2 system. In particular, due to the short recovery times, we predicted that VCl-NiCl2 could be utilized as a promising gas sensor for CO at 398 K and O2 under ambient conditions. Our results not only further expand the potential application of NiCl2 monolayers as a gas sensor, but also offer new options for developing candidate detection materials for toxic gases. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of CO2 (CO2RR) using renewable electricity to produce value-added chemicals offers a promising way of reducing carbon emissions. Cu-based bimetals are good catalysts for the CO2RR. Industrial CO2 sources usually contain SO2 impurity gas. Understanding the effect of SO2 on the CO2 reduction performance of Cu-based bimetallic electrocatalysts is very important for developing catalysts with practical application value. Herein, the effect of SO2 on the CO2RR of Cu-based bimetallic catalysts was investigated by density functional theory (DFT). Three possible factors affecting the CO2 reduction performance of the M@Cu catalysts were studied. The results show that SO2 is easily adsorbed on the catalyst surface and reduced to S elemental substance. S adsorbed on the surface increases the overpotential of CO2 catalytic conversion. Among the ten kinds of catalysts considered, Pd@Cu shows better catalytic activity than other M@Cu catalysts. The ΔGPLS of CO2RR-to-CO increases with the rise of coverage (Θ) for the Pd@Cu catalysts after SO2 adsorption, because SO2 molecules adsorbed on the catalyst surface occupy the active sites, and increased coverage causes more active sites to be occupied. Moreover, the adsorption of intermediate species (SO4*, SO3*, and S*) on the catalyst surface increases the overpotential of the CO2RR. The formation of Cu2S affects the CO2 reduction process because the overpotential of the CO2RR on Cu2S(111) is smaller than that on Pd@Cu catalysts. These mechanistic insights can guide the rational design of SO2-resistant catalysts in the CO2 electrocatalysis field. [ABSTRACT FROM AUTHOR]

Titanium complexes bearing 2-(arylideneamino)phenolates and 2-((arylimino)methyl)phenolates were synthesized, and their catalytic activities in the polymerization of ε-caprolactone and L -lactide were studied. Among five-membered ring Ti complexes bearing 2-(arylideneamino)phenolates, FCl-Ti exhibited the highest level of catalytic activity ([CL] : [FCl-Ti] = 100 : 1, where [CL] = 2 M, and conv. = 86% at 60 °C after 9 h). For six-membered ring Ti complexes bearing 2-((arylimino)methyl)phenolates, SCl-Ti exhibited the highest level of catalytic activity ([CL] : [SCl-Ti] = 100 : 1, where [CL] = 2 M, and conv. = 88% at 60 °C after 118 h). The five-membered ring Ti complexes bearing 2-(arylideneamino)phenolates exhibited a higher level of catalytic activity (6.1–12.8 fold for the polymerization of ε-caprolactone and 6.2–23.0 fold for the polymerization of L -lactide) than the six-membered ring Ti complexes bearing 2-((arylimino)methyl)phenolates. The density functional theory (DFT) results revealed that the free energy of the first transition state FH-Ti-TS1 is 36.49 kcal mol−1 which is lower than that of SH-Ti-TS1 (46.58 kcal mol−1), which was ascribed to the fact that the Ti–Nim bond (2.742 Å) of FH-Ti-TS1 is longer than that of SH-Ti-TS1 (2.229 Å) and reduces the repulsion between ligands. [ABSTRACT FROM AUTHOR]

With an electron-deficient rigid planar structure and excellent π–π stacking ability, hexaazatriphenylene (HAT) and its derivatives are widely used as basic building blocks for constructing covalent organic frameworks (COFs), components of organic light-emitting diodes and solar cells, and electrode materials for lithium-ion batteries (LIBs). Here, a HAT derivative, hexaazatriphenylenehexacarbonitrile, is explored as an anode material for LIBs. The HAT anode exhibited high initial reversible capacities of 672 mA h g−1 at 100 mA g−1 and 550 mA h g−1 at 400 mA g−1 and stable cycling with a capacity of 503 mA h g−1 after 1000 cycles at 400 mA g−1 corresponding to a capacity retention of 91.5%. Furthermore, the lithium storage mechanism and the cause of the first irreversible capacity loss of the HAT anode were investigated by X-ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculations. We have carried out a series of analyses on the mechanism of initial capacity loss. This study provides new insight on initial capacity loss and provides valuable insights into the molecular design and the electrochemical properties of HAT-based anode materials. [ABSTRACT FROM AUTHOR]

Solid-state phosphor-converted white light-emitting diodes (pc-WLEDs) are the leading trend of the lighting industry in the 21st century. To pursue high quality WLED lighting, the development of highly efficient phosphors with tunable luminescence has become a hot research topic. Herein, we reported for the first time on Bi3+/Eu3+-doped Li3Ba2Y3(WO4)8 phosphors that exhibited tunable emission and high energy transfer efficiency of 89.90% from Bi3+ to Eu3+. The phase purity, microstructure, electronic structure and photoluminescence properties of these phosphors were studied in detail. Bi3+ and Eu3+ were effectively doped in Li3Ba2Y3(WO4)8 with an optical bandgap of 3.81 eV. The band structure and density of states were quantitatively evaluated by density functional theory simulation. At an excitation wavelength of 342 nm, the Bi3+-doped phosphor achieved yellow-green emission. By alloying Eu3+ into Li3Ba2Y3(WO4)8:Bi3+, the luminescence gradually turned red due to the energy transfer from Bi3+ to Eu3+. Moreover, the activation energy of the prepared phosphor was 0.1897 eV, demonstrating excellent thermal stability. Eventually, by combining Li3Ba2Y3(WO4)8:4%Bi3+,4%Eu3+ and a blue-emitting BAM:Eu2+ phosphor with a 365 nm ultraviolet chip, a WLED device with a high colour rendering index (Ra) of 78.7, chromaticity coordinates of (0.3401, 0.3131) and correlated colour temperature of 5080 K was successfully achieved. This work provided new insights into the design and development of color-tunable phosphors for white LEDs. [ABSTRACT FROM AUTHOR]

The sodium tellurosilicates Na4SiTe4, Na10Si2Te9, Na6Si2Te6 and Na8Si4Te10 were synthesized by ball milling and subsequent high temperature solid state reactions and analyzed by electrochemical impedance spectroscopy. All compounds show moderate to remarkable sodium ion conductivities. The crystal structures of the novel materials Na4SiTe4 and Na10Si2Te9 were determined by X-ray diffraction. Both compounds represent new structure types with isolated SiTe4 tetrahedra. The crystal structure of Na10Si2Te9 exhibits a single telluride anion besides two SiTe4 tetrahedra. Na4SiTe4 crystallizes in the cubic space group Pa3¯ (no. 205) with lattice parameters a = 13.0312(1) Å and V = 2212.84(2) Å3. Na10Si2Te9 crystallizes in the orthorhombic space group Pna21 (no. 33) with lattice parameters a = 12.8235(7) Å, b = 14.8398(8) Å, c = 12.9530(7) Å and V = 2464.9(2) Å3. The presence of two different anionic units makes this compound stand out from other alkali chalcogenotetrelates. The electronic structure of all compounds was investigated by density functional theory, revealing their semiconducting behaviour. [ABSTRACT FROM AUTHOR]

Multiple stimuli-responsive molecular crystals have gained significant attention recently owing to their wide-range of applications in diverse fields such as optical switches, storage devices, and mechanical actuators. In this study, a nitropentaammine cobalt(III) complex stabilized by 4-nitro cinnamate (C-1) was synthesized and characterized using various spectroscopic and analytical techniques, including singlecrystal X-ray diffraction (SCXRD) study. The complex C-1 exhibits dual-responsive behaviour under UV light (365 nm) and heat, showing bending, cracking, splitting, and displacement. These photo-/thermomechanical responses are attributed to nitro-to-nitrito linkage isomerization within the crystalline phase. The energy optimization of C-1 and its corresponding nitrito isomer through density functional theory (DFT) study reveals that the nitro isomer is energetically more stable than nitrito by 24 kcal mol-1. This indicates that upon irradiation of UV light/heat, the nitro compound gains energy and is converted to the nitrito isomer. The photo-/thermo-mechanical behaviour of C-1 was successfully transferred to a polymer composite, which was fabricated via a solution casting method using C-1 and agarose (1 : 1 weight ratio) and shows actuating behaviour, with the extent of actuation varying for both the external stimuli. [ABSTRACT FROM AUTHOR]

Copper in vegetables can enter the human body, and excessive copper may cause uncomfortable symptoms; thus, it is urgent to test copper ions for safety concerns. Herein, we prepared Zn2GeO4:Mn2+,In3+ (ZGO:Mn,In) persistent luminescent nanoparticles (PLNPs) and then grafted glutathione for the determination of copper ions. ZGO:Mn,In was prepared by doping In3+ in ZGO:Mn to improve the emission at 532 nm under excitation at 258 nm. The doping amount, temperature, time, and pH were carefully optimized for a stronger emission intensity than ZGO:Mn. The fractional densities and energy band gaps were calculated by density functional theory, revealing the excitation enhancement mechanism of ZGO:Mn,In. The surface of ZGO:Mn,In was modified with carboxyl groups for linking glutathione to specially identify Cu2+ ions. The identification resulted in the aggregation-induced quenching of PLNPs' emission. Thus, the sensor exhibited good selectivity for copper ions, and the composite was successfully applied to the detection of copper ions in serum and vegetable samples. [ABSTRACT FROM AUTHOR]

The stable contact of heterogeneous interfaces and the substantial exposure of active sites are crucial for enhancing the photocatalytic performance of semiconductor catalysts. However, most reported two-dimensional (2D)/2D CsPbBr3 and BiOCl heterostructures are fabricated using electrostatic self-assembly methods, which exhibit significant deficiencies in precise interface quality control and effective active site exposure. In this study, we fabricate a zero-dimensional (0D)/2D CsPbBr3/BiOCl heterojunction via a two-step calcination method, achieving an efficient direct S-scheme configuration. Optimizing interfacial contact and band alignment between CsPbBr3 quantum dots and BiOCl nanosheets enhances cross-plane charge transfer, promoting superior charge separation. This 0D/2D CsPbBr3/BiOCl heterojunction exhibits enhanced carrier mobility and high conversion rates without cocatalysts or sacrificial agents. The mechanism underlying the accelerated S-scheme charge transfer is comprehensively elucidated through a combination of analytical techniques and density functional theory (DFT) calculations. This study offers a novel approach for managing charge carrier segregation and mobility in CO2 reduction photocatalysts. [ABSTRACT FROM AUTHOR]

Glycolysis of waste polyethylene terephthalate (PET) is a green and high-value PET recovery approach, the product of which can be used as raw materials to prepare polyurethanes. Enhancing the conversion rate and monomer selectivity of PET glycolysis through the development of efficient catalysts is crucial for reducing both the energy consumption and operational costs associated with the process. In this study, a series of deep eutectic solvents (DESs) were synthesised based on L-proline (Pro) and its derivatives and used as catalysts for the glycolysis of PET using 1,4-butanediol (BDO). Under the optimized reaction conditions (5.0 g PET, 25.0 g BDO, 2 wt% Pro/Zn(Ac)2 catalyst, 210 °C, 15 min and atmospheric pressure), PET was degraded completely, and the yield of monomeric bis(4-hydroxybutyl)terephthalate (BHBT) reached 67.1%. Based on the results of in situ-IR, ¹H NMR and density functional theory (DFT), the possible catalytic mechanism of DESs synergistically promoting PET depolymerization was proposed. Finally, aromaticbased polyurethane elastomers (PUEs) were prepared with PET glycolysis products bis(2-hydroxyethyl) terephthalate (BHET) and BHBT as chain extenders. Compared with the control group, the thermal and mechanical properties of aromatic-based PUEs were improved, which proved the feasibility of high value utilization of PET glycolysis products. [ABSTRACT FROM AUTHOR]

In this study, we present a series of theoretically designed B2G14G14' molecules, featuring four-membered-ring heterocycles containing boron and heavy group 14 elements (G14 and G14' = Si, Ge, Sn, and Pb). Through the use of density functional theory (DFT), natural bond orbital (NBO) analysis, quantum theory of atoms in molecules (QTAIM), and electron localization function (ELF), our studies demonstrate a strong π single bond between the bridgehead G14 and G14' atoms, with minimal participation from a very weak G14-G14' σ bond. Additionally, the nucleus independent chemical shift (NICS), anisotropy of current-induced density (ACID), and adaptive natural density partitioning (AdNDP) analyses definitively establish the presence of both σ-aromaticity and π-aromaticity in these inorganic four-membered heterocyclic neutral molecules. [ABSTRACT FROM AUTHOR]

Generally, thiophene/benzene-fused π-conjugated systems have been the go-to core units for enhancing the electrical conduction and charge transport characteristics of 2D hole-transporting materials (HTMs). However, while thiophene-fused units have been extensively studied, the investigation into benzene-fused π-conjugated cores has been relatively limited. In order to explore the untapped potential of benzene-fused π-conjugated systems in HTMs, we have designed three new molecules utilizing polycyclic triphenylene, pyrene and perylene as core units. These molecules were then simulated using density functional theory in conjunction with the Marcus theory of electron transfer. Our findings reveal that the highest occupied molecular orbital (HOMO) levels of these newly developed HTMs are 0.14–0.29 eV lower compared to Spiro-OMeTAD, a commonly used HTM, potentially leading to an increase in the open circuit voltage of solar cell devices. Additionally, the enhanced electronic interaction between neighboring molecules and lowered reorganization energies contribute to high hole mobilities, measured at 5.08 × 10−3 cm2 V−1 s−1, 7.38 × 10−3 cm2 V−1 s−1 and 9.31 × 10−1 cm2 V−1 s−1, respectively. Furthermore, these new molecules exhibit weak visible light absorption and significant Stokes shifts, both of which are advantageous for HTM performance enhancement. Overall, our calculations suggest that these benzene-fused π-conjugated core molecules are promising as HTM candidates, paving the way for more effective solar cells. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) transition metal dichalcogenides (TMDs) possess a wide range of functionalities due to their highly tunable chemical, physical, and electronic properties. In this study, we systematically explore the structural, electronic, and phonon characteristics of six TMD systems using density functional theory (DFT) simulations. Our analysis covers both the semiconducting (2H) and metallic (1T) phases of these TMD systems. Specifically, we investigate group-V TMDs (AB2, where A = Nb, Ta, and B = S, Se, Te), examining their structure–property relationships and electronic behaviors to validate the accuracy of various exchange–correlation (XC) functionals, including van der Waals density functionals (vdW-DFs). Our calculations account for both spin–orbit coupling (SOC) and non-SOC (NSOC) scenarios. The results reveal significant impacts on vdW gaps, lattice parameters, and electronic band structures in both the 2H and 1T phases, highlighting their potential for conventional applications. [ABSTRACT FROM AUTHOR]

In this study, red mud (RM), an industrial waste, was used as a raw material to prepare a novel red mud-based Co3O4–Fe2O3–Co2AlO4 (Co–Fe/RM) catalyst using a simple solid-phase method, and lomefloxacin hydrochloride (LOMH) was degraded by using Co–Fe/RM to activate peroxymonosulfate (PMS). The optimum preparation conditions of the mass ratio of Co(NO3)2·6H2O to RM, calcination temperature and calcination time were 1.5 : 1 (1.5 g of Co(NO3)2·6H2O and 1 g of RM), 700 °C, and 2 h, respectively. The characterization results showed that Fe2O3, Co3O4 and Co2AlO4 were the main active components in Co–Fe/RM, and Co–Fe/RM could expose more reaction sites compared with RM. The Co–O–Al bonds that existed on the Co–Fe/RM could facilitate the redox cycle between Co(II) and Co(III), thus improving the Co–Fe/RM catalytic activity. For 10 mg L−1 LOMH solution with a volume of 100 mL, the maximal removal ratio of LOMH (89.3%) was obtained at 20 min under the optimal parameters (0.3 g L−1 Co–Fe/RM dosage, 1 mmol L−1 PMS concentration, initial pH 5.5, and 30 °C of reaction temperature) in a Co–Fe/RM/PMS system. The trapping experiments proved that SO4˙−, 1O2 and O2˙− dominated the degradation of LOMH, and a possible catalytic mechanism of activating PMS using the prepared catalysts was proposed. For LOMH in the Co–Fe/RM/PMS system, degradation pathways were analyzed via density functional theory (DFT) calculations and liquid chromatography–mass spectrometry (LC–MS). A toxicity estimation software tool (TEST) and the Chlorella pyrenoidosa cultivation experiment were used to evaluate the biological toxicity of the treated LOMH solution. The recycling experiments found that the Co–Fe/RM had distinguished reusability and excellent stability. The mineralization assessment showed that organic carbon contents could be effectively diminished in the treated LOMH solution. This study provided a viable way for the beneficial use of RM to activate PMS and offered a low-cost and efficient catalyst for the degradation of pollutants in wastewater. [ABSTRACT FROM AUTHOR]

The helix preferences of cyclopentane-containing β/γ-hybrid oligomers, consisting of alternating βAc5a (2-aminocyclopentanecarboxylic acid) and γ(Et)Ac5a [2-(2-aminocyclopentyl)butanoic acid] residues with homochiral S-configurations, were investigated through conformational searches and density functional theory calculations in chloroform. The β/γ-hybrid dimer exhibited a distinct inclination toward a ribbon-like structure characterized by alternating C8 and C9 H-bonds. However, for β/γ-hybrid oligomers longer than tetramer, a preference for a right-handed (P)-2.413-helical structure emerged. The robust stabilities observed for the H13 helical structures in chloroform were attributed to the favored solvation free energies, which increased with the length of the peptide sequence. Calculations revealed that the mean backbone torsion angles of the H13 helix foldamer in the β/γ-hybrid pentamer closely resembled those observed in X-ray structures of the pentamer consisting of βAc5a and a γ-residue with a cyclohexane substituent. The introduction of cyclopentane substitutions led to distinct conformational preferences and/or handedness of helix foldamers compared to those of the unsubstituted β/γ-hybrid oligomers. Notably, a pyrrolidine-substituted analog of the H13 helical structure for the β/γ-hybrid pentamer, with adjacent amine diads substituted in close proximity, appears to be a promising organic catalyst for organic reactions such as the crossed aldol condensation and the cyclodimerization of dialdehyde in nonpolar solvents, as previously elucidated. [ABSTRACT FROM AUTHOR]

Efficient hydrogen evolution reaction (HER) electrocatalysts are crucial for renewable energy storage and conversion. Pt remains the most efficient HER catalyst, but its widespread application is hindered by cost and resource constraints. In this study, we investigate the HER electrocatalytic activities of free-metal SiC monolayers through doping and strain engineering. Through density functional theory (DFT) calculations, we explore the effects of B, N, S, and P doping on the HER performance of SiC. Our results reveal that B and P doping enhance the catalytic activity, with P doping showing the most promising activity due to its smaller ΔGH* values. Furthermore, we apply tensile strain to modulate the HER activity of P-doped SiC, achieving further improvements. We also construct composite structures of P-doped SiC with graphene, enhancing conductivity and catalytic performance. Our findings provide valuable insights into tailoring the HER catalytic properties of SiC monolayers, offering a pathway towards sustainable hydrogen production. [ABSTRACT FROM AUTHOR]

We describe a new quadrupolar NMR crystallography guided crystal structure prediction (QNMRX-CSP) protocol for the prediction and refinement of crystal structures, including its design, benchmarking, and application to seven organic HCl salts. Five HCl salts with a limited number of low-energy conformations were chosen as model systems for benchmarking: betaine HCl, glycine HCl, D -alanine HCl, guanidine HCl, and aminoguanidine HCl; two were chosen for blind tests: N,N′-dimethylglycine HCl and metformin HCl. The QNMRX-CSP protocol uses experimental 35Cl solid-state NMR (SSNMR) spectra and X-ray diffraction (XRD) data in tandem with Monte Carlo simulated annealing and dispersion-corrected plane-wave density functional theory (DFT-D2*) calculations. The protocol comprises three modules: (i) the assignment of motion groups, (ii) a Monte Carlo simulated annealing algorithm for generating tens of thousands of candidate structures, and (iii) DFT-D2* geometry optimizations of structural models and concomitant computation of 35Cl EFG tensors. Key benchmarked metrics are used for retaining the best candidate structures, including unit cell parameters, static lattice energies, and EFG distances (ΓEFG). The protocol is shown to generate structural models that are excellent matches with experimental crystal structures that have been DFT-D2* geometry optimized, as validated by crystallographic R-factors (R) and root-mean squared distances (RMSDs) of atomic positions that are well below 10% and 0.2 Å, respectively. Finally, consideration is given to the use of the QNMRX-CSP protocol as a standalone technique or in concert with other NMRX methods and Rietveld refinements, and possible applications employing other quadrupolar nuclei (i.e., 14N and 17O). [ABSTRACT FROM AUTHOR]

L -Glutamic acid (L -Glu) is a basic unit of proteins and also serves as an important neurotransmitter in the central nervous system. Its structural properties are critical for biological functions and selective receptor recognition. Although this molecule has been extensively studied, the low frequency vibrational behavior that is closely related to conformational changes and the intermolecular interactions between L -Glu and its receptors are still unclear. In this study, we acquired the fingerprint spectrum of L -Glu by using air plasma terahertz (THz) time-domain spectroscopy in the 0.5–18 THz range. The low frequency vibrational characteristics of L -Glu were investigated through density functional theory (DFT) calculations. The THz responses of the ligand binding domain of the NMDAR– L -Glu complex were studied by the ONIOM method, with a focus on discussing the normal modes and interactions of ligand L -Glu and water molecules. The results illustrate that THz spectroscopy exhibits a sensitive response to the influence of L -Glu on the structure of the NMDAR. The water molecules in proteins have various strong vibration modes in the THz band, showing specificity, diversity and complexity of vibrational behavior. There is potential for influencing and regulating the structural stability of the NMDAR– L -Glu complex through water molecules. [ABSTRACT FROM AUTHOR]

The mechanical properties of halide perovskites have been attracting ever-increasing interest for their significant importance in future industrial applications. However, studies focused on the effect of B-site substitution of molecular perovskites on their mechanical properties are rare, which makes it favorable to shed light on their fundamental structure--mechanical property relationships. Here, using isostructural halide perovskites, [C4H12N2][BCl3]•H2O(B=NH4+;K+), constructed by ionic bonds and hydrogen bonds, respectively, as the model systems, we investigate their mechanical properties through high-pressure synchrotron X-ray diffraction experiments and density functional theory calculations. Owing to the similar sizes of NH4+ and K+, the two compounds possess almost identical cell parameters and frameworks. Upon compression, the two perovskites exhibit analogous behavior except for slight differences in the shrinkage ratio of principal axes and the onset pressure of amorphization. The fitted bulk moduli of [C4H12N2][KCl3]•H2Oand[C4H12N2][NH4Cl3]•H2O are 43.89 and 27.28 GPa, respectively. These results demonstrate that the simple replacement of K+ by NH4+ can significantly reduce the structural rigidity of the corresponding compounds, which is ascribed to the weaker strength of NH4...Cl hydrogen bonds than that of K-Cl bonds. [ABSTRACT FROM AUTHOR]

This study employs density functional theory at the SMD/B3LYP-D3/6-311+G(2d,p),def2-TZVPP//SMD/B3LYP-D3/6-31G(d),SDD level of theory to explore the mechanistic details of O2 generation from tBuOOH, using H218O as the solvent, in the presence of the Mn(II) catalyst [Mn2(mcbpen)2(H2O)2]2+. Since this chemistry was reported to occur through the reaction of Mn(III)(μ-O)Mn(IV)–O˙ with water, we first revaluated this proposal and found that it occurs with an activation barrier greater than 36 kcal mol−1, ruling out the functioning of such a dimer as the active catalyst. Experimental evidence has shown that the oxidation of [Mn2(mcbpen)2(H2O)2]2+ by tBuOOH in H218O produces the Mn(IV) species [Mn(18O)(mcbpen)]+. Our investigations revealed a plausible mechanism for this observation in which [Mn (18O)(mcbpen)]+ acts as the active catalyst, generating the tert-butyl peroxyl radical (tBuOO˙) through its reaction with tBuOOH. In this proposed mechanism, the O–O bond is formed through the interaction of tBuOO˙ with another [Mn(18O)(mcbpen)]+, finally leading to the formation of the 16O＝18O product. Our findings underscore the pivotal role of [Mn(18O)(mcbpen)]+ in both generating the active species tBuOO˙ and consuming it to produce 16O＝18O. With activation barriers as low as about 9 kcal mol−1, these elementary steps highlight the feasibility of our proposed mechanism. Moreover, this mechanism elucidates why, experimentally, one of the oxygen atoms in the released O2 comes from water, while the other originates from tBuOOH. This research broadens our understanding of high oxidation state manganese chemistry, setting the stage for the development of more efficient Mn-based catalysts, aimed at improving processes in both renewable energy and synthetic chemistry. [ABSTRACT FROM AUTHOR]

Square planar complexes of Ni(II) and Pd(II) of a new redox-active pentadentate azo-appended 2-aminophenol ligand (H4L = N,N′-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2′-diamino-ortho-azobenzene) in three accessible redox levels [amidophenolate(2−), semiquinonate(1−) π radical, and quinone(0)] were synthesized. The coordinated HL(3−) ligand provides four donor sites [two N(iminophenolates), an N′(azo), and an O(phenolate)], while the phenolic OH group remains free in the three complexes. Cyclic voltammetry on complex [Ni(L)] 1 and its corresponding Pd(II) analogue [Pd(L)] 2 in CH2Cl2 displayed three redox responses (two oxidative at E1/2 = 0.06 V and Epa (anodic peak potential) = 0.80 V and one reductive at −0.77 V for 1 and at E1/2 = 0.08 V and Epa = 0.85 V and at −0.74 V for 2vs. Fc+/Fc). The chemical oxidation of 1 with AgSbF6 afforded [Ni(L)]SbF6·2CH2Cl2 (3·2CH2Cl2). Complex [Pd(L*)] 4, which is coordinated by a phenoxazinyl derivative of L(4−), was obtained via intraligand cyclization in the parent complex 2 under basic oxidizing conditions. The molecular structures of 1, 2, 3·2CH2Cl2 and 4 were elucidated through X-ray crystallography at 100 K. Characterization using 1H NMR, X-band EPR, and UV–VIS–NIR spectroscopy established that the complexes have [NiII{(LISQ)˙2−}] 1, [PdII{(LISQ)˙2−}] 2, [NiII{(LIBQ)−}]SbF6/1+SbF6−(3), and [PdII{(L*AP)˙2−}] 4 electronic states. Complexes 1, 2, and 4 possess paramagnetic St (total spin) = 1/2 ground-state, whereas 3 is diamagnetic (St = 0). Density functional theory (DFT) electronic structural calculations at the B3LYP level rationalized the observed experimental results. Time-dependent (TD)-DFT calculations allowed us to identify the nature of the observed absorption spectra. [ABSTRACT FROM AUTHOR]

Metal halide perovskites with suitable energy band structures and excellent visible-light responses have emerged as promising photocatalysts for CO2 reduction to valuable chemicals and fuels. However, the efficiency of CO2 photocatalytic reduction often suffers from inefficient separation and sluggish transfer. Herein, a step-scheme (S-scheme) CsPbBr3/BiOBr photocatalyst with oxygen vacancies possessing intimate interfacial contact was fabricated by anchoring CsPbBr3 QDs on BiOBr-Ov nanosheets using a mild anti-precipitation method. The results showed that CsPbBr3/BiOBr-Ov-2 with an internal electric field (IEF) heterojunction exhibited a boosted evolution rate of 27.4 μmol g−1 h−1 (CO: 23.8 μmol g−1 h−1 and CH4: 3.6 μmol g−1 h−1) with an electron consumption rate (Relectron) of 76.4 μmol g−1 h−1, which was 5.9 and 3.2 times that of single CsPbBr3 and BiOBr-Ov, respectively. Density functional theory (DFT) calculations revealed that BiOBr with oxygen vacancies can effectively enhance the adsorption and activation of CO2 molecules. More importantly, in situ infrared Fourier transform spectroscopy (DRIFTS) spectra show the transformation process of the surface species, while the femtosecond transient absorption spectrum (fs-TA) reveals the charge transfer kinetics of the CsPbBr3/BiOBr-Ov. Overall, this work provides some guidance for the rational design of S-scheme heterojunctions and vacancy-engineered photocatalysts, which are expected to have potential applications in the fields of photocatalysis and solar energy conversion. [ABSTRACT FROM AUTHOR]

The catalytic efficiency of CeO2 in soot oxidation was significantly affected by its grain morphology and calcination temperature. Nanocube-shaped and nanorod-shaped CeO2 catalysts were synthesized via a hydrothermal method with different calcination temperatures. Activity tests revealed that the nanorod-shaped CeO2 exhibited superior catalytic activity compared to the nanocube-shaped catalysts at equivalent calcination temperatures. Furthermore, an inverse relationship between the catalytic activity and the calcination temperature was observed in the nanorod-shaped CeO2 catalysts, with those calcined at 300 °C exhibiting the most effective low-temperature catalytic performance. Combined characterization techniques and density functional theory calculations showed that the improved catalytic performance can be attributed to the increased abundance of oxygen vacancies, enhanced lattice oxygen mobility and higher surface energy due to their unique surface defect structure and electronic structural feature, in addition to the reduction in grain size. [ABSTRACT FROM AUTHOR]

Pesticides are extensively employed worldwide, particularly in less developed countries. These substances, designed to eradicate insects in plantations, permeate the soil, groundwater, and rainwater. As these waters traverse plantations, pesticides are carried into rivers, resulting in contamination of aquatic ecosystems. Consequently, there is a pressing need to detect and eliminate these toxic compounds from the environment. In this study, we employ first principles calculations, utilizing the density functional theory within the Siesta computer program, to analyze the nano-interactions between commonly-used pesticides acephate and glyphosate with graphene. The main theoretical findings indicate that both acephate and glyphosate exhibit a physical interaction with graphene, as evidenced by the assessments of binding energy across all the configurations analyzed. Consequently, we propose that graphene shows potential as an effective filter for eliminating acephate and glyphosate pesticides from aquatic environments, given the observed physical interactions. This research could significantly contributes to the emergent field of computational nanoecotoxicology, anticipating potential toxic effects on human health and promoting efficient bioremediation strategies based on graphene nanomaterials properties. [ABSTRACT FROM AUTHOR]

The hyphenation of HPLC with its high separation ability and ICP-MS with its excellent sensitivity, allows the analysis of Pt drugs in biological samples at the low nanomolar concentration levels. On the other hand, LC-MS provides molecular structural confirmation for each species. Using a combination of these methods, we have investigated the speciation of the photoactive anticancer complex diazido Pt(IV) complex trans, trans, trans-[Pt(N3)2(OH)2(py)2] (FM-190) in aqueous solution and biofluids at single-digit nanomolar concentrations before and after irradiation. FM-190 displays high stability in human blood plasma in the dark at 37 °C. Interestingly, the polyhydroxido species [{PtIV(py)2(OH)4} + Na]+ and [{PtIV(py)2(N3)(OH)3} + Na]+ resulting from the replacement of azido ligands, as determined by LC-MS, were the major products after photoirradiation of FM-190 with blue light (463 nm). This finding suggests that such photosubstituted Pt(IV) tri- and tetra-hydroxido species could play important roles in the biological activity of this anticancer complex. Density Functional Theory (DFT) and Time-Dependent DFT (TDDFT) calculations show that these Pt(IV) species arising from FM-190 in aqueous media can be formed directly from a singlet excited state. The results highlight how speciation analysis (metallomics) can shed light on photoactivation pathways for FM-190 and formation of potential excited-state pharmacophores. The ability to detect and identify photoproducts at physiologically-relevant concentrations in cells and tissues will be important for preclinical development studies of this class of photoactivatable platinum drugs. [ABSTRACT FROM AUTHOR]

The present investigation utilizes density functional theory (DFT) to elucidate the influence of iron (Fe) and ruthenium (Ru) as dopants, alongside sulfur (S) co-doping, on the electronic properties and photocatalytic properties of zinc oxide (ZnO) monolayer nanosheets. The findings indicate that the integration of Fe and Ru dopants serves to augment structural stability while concomitantly diminishing the bandgap energy through an elevation of the valence band maximum (VBM). Doping of Fe and Ru along with co-doping up to three sulfur atoms into the ZnO lattice has been observed to result in a compromise of structural stability while concurrently enhancing the specific surface area. The introduction of sulfur expands the bandgap in Fe-doped ZnO nanosheets, enhancing the VBM energy, while for Ru-doped ZnO nanosheets, sulfur doping narrows the bandgap. This effect is especially notable in RuS3 co-doped nanosheets, making them well-suited as a photocatalyst for the overall water splitting process at pH = 7. Furthermore, the increased probability of effective electron–hole pair separation, combined with a bandgap of 3.52 eV, positions FeS-co-doped ZnO as a promising photocatalytic material for the generation of hydrogen via water splitting under near-ultraviolet illumination. [ABSTRACT FROM AUTHOR]

To design highly efficient, low-cost, and stable electrocatalysts for the oxygen evolution reaction (OER), we built a ferromagnetic Fe3GeTe2 (001) basal plane and (100), (110) tellurium iron mixed edge planes, which exhibit good stability owing to the lower surface energy. Density functional theory (DFT) calculation reveals that the edge planes exhibit better OER activity, which is attributed to the synergistic effect between the active site of Fe and Te atoms. For the (100) and (110) edge planes, active site transfer occurs from Te to the Fe atom, and with Te and Fe atoms synergistically acting as the active sites, Fe3GeTe2 exhibits favorable adsorption and desorption of oxygen-containing intermediates during the OER process. These interesting findings may provide important and valuable references for the design of emerging two-dimensional ferromagnetic electrocatalysts. [ABSTRACT FROM AUTHOR]

Due to their high anisotropic behavior, liquid crystals possess strong nonlinear optical properties. The RM734 liquid crystal is famous for having high anisotropic behaviors compared to traditional liquid crystals. The present work focused on the evaluation of electronic, charge-transport, nonlinear optical, electro-optical, and thermochemical properties of the RM734 liquid crystal. Furthermore, the effect of halogenation on the above properties of RM734 was investigated and is discussed in depth as halogen substitution on the liquid crystal molecule can alter the quantum mechanical properties of any liquid crystal molecule. Density functional theory combined with B3LYP and dispersion correction were used to calculate the properties of RM734. The 6-311G** basis set was used for the estimation of these properties, whereas def2-TZVPD was used to evaluate the nonlinear optical parameters. Due to the halogenation of RM734, its electronic properties vary significantly. By halogenation, a better electron-transport molecule can be converted into a hole-transport molecule. The electro-optical properties were calculated with the application of an external electric field for all molecules. With the help of the order parameter, the nematic phase was observed for all reported molecules. The variation in the birefringence with respect to the external electric field was investigated and discussed in detail. Therefore, the present study reveals the significant impact of halogenation in terms of the nonlinear optical and thermochemical properties of RM734. [ABSTRACT FROM AUTHOR]

Treatment of [Co(N2)(tBuPNP)] (tBuPNP = anion of 2,5-bis(di-tert-butylphosphinomethyl)pyrrole) with one equivalent of an aryl azide generates the four-coordinate imido complexes [Co(NAr)(tBuPNP)] (Ar = mesityl, phenyl, or 4-tBu-phenyl). X-ray crystallographic analysis of the compounds shows an unusual square-planar geometry about cobalt with nearly linear imido units. In the presence of the hydrogen atom donor, TEMPOH, [Co(NPh)(tBuPNP)] undergoes addition of the H atom to the imido nitrogen to generate the corresponding amido complex, [Co(NHPh)(tBuPNP)], whose structure and composition were verified by independent synthesis. Despite the observation of H atom transfer reactivity with TEMPOH, the imido complexes do not show catalytic activity for C–H amination or aziridination for several substrates examined. In the case of [Co(NPh)(tBuPNP)], addition of excess azide produced the tetrazido complex, [Co(N4Ph2)(tBuPNP)], whose bond metrics were most consistent with an anionic Ph2N4 ligand. Density Functional Theory (DFT) investigations of the imido and tetrazido species suggest that they adopt a ground state best described as possessing a low-spin cobalt(II) ion ferromagnetically coupled to an iminyl radical. [ABSTRACT FROM AUTHOR]

Density functional theory calculations have been performed to compare the HCHO decomposition on Co3O4(110)-A and (110)-B terminations. The results showed that the energy barriers of the two C–H bond cleavages of HCHO on the (110)-A termination were lower than those on the (110)-B termination, suggesting that the (110)-A termination had stronger HCHO decomposition ability than the (110)-B termination. Electronic structures revealed that the stronger HCHO decomposition ability of the (110)-A termination might be ascribed to the strong covalent bond between HCHO and the (110)-A termination, as well as the higher d-band center of Co3+ ions on the (110)-A termination. Furthermore, we proposed that the preparation of Co3O4 under oxygen-rich growth conditions was beneficial to HCHO decomposition because the (110)-A termination was more stable under oxygen-rich conditions. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of biomass-derived furfural (FF) is an advantageous route to alleviate the consumption of fossil fuels and hydrogen. However, the development of efficient catalytic systems to obtain furfuryl alcohol (FAL) with high selectivity is still challenging. Herein, a copper nitride nanowire catalyst in situ grown on copper foam (Cu3N Nw/CF) is synthesized, which achieves nearly 100% selectivity for FAL with 94.6% faradaic efficiency (FE) in the electrochemical reduction of FF. Thiol assembly and operando Raman investigations reveal an adsorptive hydrogen (Hads) dependent electrocatalytic hydrogenation (ECH) pathway for FAL production. Moreover, electrokinetic studies have demonstrated that the FF hydrogenation on Cu3N Nw/CF follows the Langmuir–Hinshelwood (L–H) mechanism. The much higher activity of Cu3N Nw/CF than that of copper foam (CF) is due to the promoted Hads spillover from water dissociation, which then reacts efficiently with FF via the ECH mechanism. Furthermore, density functional theory (DFT) calculations verify that the superior water dissociation ability and the preferable parallel FF adsorption on Cu3N synergistically enhance the thermodynamics and kinetics of FAL production. [ABSTRACT FROM AUTHOR]

The energy difference between different spin states of systems with transition metals is an outstanding challenge for electronic structure calculation methods. The small energy difference between high- and low-spin states in spin-crossover systems makes most post-Hartree–Fock or density functional theory-based methods provide inaccurate values. A test case of twenty systems showing spin transitions has been used to evaluate the accuracy of a new family of training meta-GGA (Generalized Gradient Approximation) functionals. One of the functionals of this new family provides comparable or even better values than the best functional reported so far for this type of system, the TPSSh hybrid meta-GGA functional, but without having to use the exact exchange term. It also improves the results obtained with the r2SCAN meta-GGA functional, which was the best alternative to the TPSSh hybrid functional. This makes it possible to calculate the spin energetics of any kind of compound, especially large systems or periodic structures where the exact exchange requires large computational resources. [ABSTRACT FROM AUTHOR]

The development of stable and durable oil/water separation materials with photocatalytic activity holds great significance for the purification of complex oily wastewater containing refractory organic pollutants. Herein, a multifunctional Ag@Cu2O decorated copper mesh was designed and prepared via a two-step hydrothermal method. The material possesses outstanding superwettability, photocatalytic activity, and antibacterial properties towards Escherichia coli and Staphylococcus aureus. The mesh demonstrates remarkable and durable superhydrophilic properties while maintaining underwater superoleophobic characteristics, enabling excellent separation efficiency and high permeability flux involving various oil/water mixtures in gravity-driven separation processes. Under visible light, the Ag@Cu2O anchored mesh serves as an effective photocatalyst in the removal of dyes and tetracycline antibiotics from aqueous solution. The catalyst shows high stability and reusability and exhibits high performance after 5 cycles of photocatalytic tests. Density functional theory calculations reveal that the improved photocatalytic performance is attributed to the narrowed indirect band gap after Ag anchoring. The silver atoms induce the shifting up of the energy level of the Cu 3d orbital, enhancing the photocatalytic activity of Cu2O. The outstanding performance of the Ag@Cu2O anchored mesh endows this material with great application potential in the removal of refractory pollutants from oily wastewater. [ABSTRACT FROM AUTHOR]

Two new pyrazolidine-3,5-dione derivatives namely (Z)-4-(2-(4-bromophenyl)hydrazono)-1-phenylpyrazolidine-3,5-dione (2) and (E)-1-phenyl-4-((pyridin-2-ylamino)methylene)pyrazolidine-3,5-dione (3) were synthesized and their structures were elucidated by single-crystal X-ray analysis along with spectroscopic techniques. Density functional theory (DFT) studies were carried out to examine the distribution of charge, and natural bond orbital (NBO) analysis and frontier molecular orbital (FMO) analysis were carried out. Hirshfeld surface analysis was carried out to examine the intermolecular interactions, revealing a prevalence of H⋯H interactions in the crystals of both molecules. NBO analysis was carried out to investigate the stabilization energy, while MEP analysis was conducted to explore regions susceptible to nucleophilic and electrophilic attacks. The molecules were screened for their medicinal potential based on physiochemical and pharmacokinetics including (gastrointestinal) GI absorption, blood brain barrier (BBB) permeation, skin permeation capability, Caco-2 permeability, Madin–Darby canine kidney (MDCK) permeability, drug metabolism by the cytochrome P450 (CYP) family of liver enzymes, and toxicity evaluations. The expected metabolic reactions in the real cell system and the resulting metabolites along with their polarities for the determination of the probability of excretion from the body and drug-likeness were studied. To investigate the anticancer potency of 2 and 3, both were docked with three enzymes as drug targets for anticancer studies including HER2 (PDB ID: 3WSQ), EGFR (PDB ID: 5WB7), and the extracellular domain of the Tdp enzyme (PDB ID: 6N0D). From the calculated binding energies and inhibition constants, 2 is a better inhibitor of the target substrates than 3. [ABSTRACT FROM AUTHOR]

The Cu⋯Cu interactions, known as cuprophilicity, play a significant role in copper–chalcogenide functional materials. Three dinuclear copper chalcogenone complexes, [(L1CuI)2] (1), [(L2CuI)2] (2) and [Cu2(L3)4]PF6 (3), have been isolated and characterized. L1 = 1-(9-methyl anthracene)-2-isopropyl-benzimidazole-2-thione; L2 = 1-(9-methyl anthracene)-2-isopropyl-benzimidazole-2-selenone and L3 = 1-pyridine-2-isopropyl-imidazole-2-selenone, ligands and 1–3 were characterized by 1H NMR, 13C NMR, FT-IR, and SCXRD. Complexes 1 and 2 compress a four-membered strained ring system bridged by iodine, whereas 3 consists of a similar-four-membered ring core bridged by a selenium ligand. The Cu⋯Cu interactions in the crystal structures are observed (2.591 Å for 1, 2.576 Å for 2, and 2.523 Å for 3). The bridging ligand shows a key contribution to the Cu⋯Cu interactions. The density functional theory calculations also confirm the presence of d10⋯d10 interactions, which are predominantly covalent in nature. The computational study also shows the effect of the bridged ligands on the d10⋯d10 interactions and overall stability of the complexes, where complex 2 is the most stable followed by 1, and after that 3, although the d10⋯d10 interactions were the strongest in the case of 3. [ABSTRACT FROM AUTHOR]