Ambient Conditions Research Articles

Synthesis and Structural Characterization of Carbazole‐Tailored Luminescent Triarylmethyl Radical and its Stable Cation

AbstractThe development of novel luminescent radicals, characterized by their unique doublet emission, endows a significant challenge. In this study, we reported the synthesis of a luminescent neutral radical, BCzAnM‐R, tailored by two carbazolyl groups and an anthryl group to achieve a nonalternant structure. It exhibited near‐infrared emission with a peak at 1020 nm in toluene. Interestingly, its corresponding cation, BCzAnM‐C, was synthesized through an unconventional SnCl2‐mediated reduction‐aromatization‐oxidation reaction in one‐pot and gram‐scale. The cation demonstrated remarkable stability for up to weeks in ambient conditions and facilitated the silica‐gel chromatography isolation as an organic salt with SnCl3− as the counter ion. The carbazolyl groups effectively modulate molecular structures, photophysical properties, and stabilities. Notably, BCzAnM‐R represents the first luminescent triarylmethyl radical with two carbazolyl groups directly attached to the central carbon.

Two‐Dimensional Silver–Isocyanide Frameworks

AbstractMetal–organic frameworks (MOFs) have been widely studied due to their versatile applications and easily tunable structures. However, heteroatom‐metal coordination dominates the MOFs community, and the rational synthesis of carbon–metal coordination‐based MOFs remains a significant challenge. Herein, two‐dimensional (2D) MOFs based on silver–carbon linkages are synthesized through the coordination between silver(I) salt and isocyanide‐based monomers at ambient condition. The as‐synthesized 2D MOFs possess well‐defined crystalline structures and a staggered AB stacking mode. Most interestingly, these 2D MOFs, without π–π stacking between layers, exhibit narrow band gaps down to 1.42 eV. As electrochemical catalysts for converting CO2 to CO, such 2D MOFs demonstrate Faradaic efficiency over 92 %. Surprisingly, the CO2 reduction catalyzed by these MOFs indicates favorable adsorption of CO2 and *COOH on the active carbon sites of the isocyanide groups rather than on silver sites. This is attributed to the critical σ donor role of isocyanides and the corresponding ligand‐to‐metal charge–transfer effect. This work not only paves the way toward a new family of MOFs based on metal–isocyanide coordination but also offers a rare platform for understanding the electrocatalysis processes on strongly polarized carbon species.

Synthesis and Structural Characterization of Carbazole-Tailored Luminescent Triarylmethyl Radical and its Stable Cation.

The development of novel luminescent radicals, characterized by their unique doublet emission, endows a significant challenge. In this study, we reported the synthesis of a luminescent neutral radical, BCzAnM-R, tailored by two carbazolyl groups and an anthryl group to achieve a nonalternant structure. It exhibited near-infrared emission with a peak at 1020 nm in toluene. Interestingly, its corresponding cation, BCzAnM-C, was synthesized through an unconventional SnCl2-mediated reduction-aromatization-oxidation reaction in one-pot and gram-scale. The cation demonstrated remarkable stability for up to weeks in ambient conditions and facilitated the silica-gel chromatography isolation as an organic salt with SnCl3 - as the counter ion. The carbazolyl groups effectively modulate molecular structures, photophysical properties, and stabilities. Notably, BCzAnM-R represents the first luminescent triarylmethyl radical with two carbazolyl groups directly attached to the central carbon.

Intermetallic Compounds for Hydrogen Storage: Current Status and Future Perspectives.

Intermetallic compounds are an emerging class of materials with intriguing hydrogen activation and storage capabilities garnering attention for their application in low-temperature hydrogen storage and metal hydride batteries. However, none of the existing intermetallic compounds have met the gravimetric hydrogen storage capacity target of 5.5wt.%. Some A2B-type intermetallic compounds, like Mg2Ni, Mg2Co, and Mg2Fe, approach this target but require high temperatures for hydrogen desorption limiting their use in low-temperature hydrogen storage and automotive applications. Conversely, some intermetallic compounds like ZrV2 and LaNi5, exhibit hydrogen desorption at ambient conditions but with comparatively lower hydrogen storage capacities. This review article provides a comprehensive account of the different types of intermetallic compounds, their synthesis using different solidification-based and solid-state diffusion-based approaches, and their metallurgical and structural properties. It examines the complex interdependencies between the structural parameters of intermetallic compounds and hydrogen storage performance. A definitive but non-linear correlation is identified between void volume and gravimetric hydrogen storage capacities while lattice structure, evolution of lattice structure with hydrogen absorption, enthalpy of hydride formation, and hydrogen activation reactivities of intermetallic compounds are identified as critical parameters governing hydrogen storage performance.

Dicyclopenta[4,3,2,1-cde:4',3',2',1'-pqr]-peri-tetracene: Synthesis and An Example of Annulene-Within-An-Annulene Aromaticity in Different Redox States.

We report a robust strategy for tuning the electronic structure and chemical stability of π-conjugated polycyclic hydrocarbons (PHs). By fusing two cyclopentadienyl rings in the peri-tetracene bay regions, we introduce antiaromatic character into the π-system, leading to unique photophysical and electronic properties. A stable mesityl-substituted dicyclopenta-peri-tetracene derivative was synthesized through stepwise formylation/intramolecular cyclization at the bay regions of the dihydro peri-tetracene precursor, followed by oxidative dehydrogenation. This compound features an open-shell singlet diradical ground state, global antiaromaticity, exceptional stability under ambient conditions, and amphoteric redox behavior with a small energy gap. Its dication also possesses an open-shell singlet ground state, and its structure was identified by X-ray crystallographic analysis, revealing a unique [14]annulene-within-[22]annulene global aromatic structure. In contrast, the dianion exhibits a closed-shell singlet ground state. This work provides valuable insights for designing and synthesizing novel open-shell PHs with tunable electronic structures and remarkable stability.

Dicyclopenta[4,3,2,1‐cde:4',3',2',1'‐pqr]‐peri‐tetracene: Synthesis and An Example of Annulene‐Within‐An‐Annulene Aromaticity in Different Redox States

We report a robust strategy for tuning the electronic structure and chemical stability of π‐conjugated polycyclic hydrocarbons (PHs). By fusing two cyclopentadienyl rings in the peri‐tetracene bay regions, we introduce antiaromatic character into the π‐system, leading to unique photophysical and electronic properties. A stable mesityl‐substituted dicyclopenta‐peri‐tetracene derivative was synthesized through stepwise formylation/intramolecular cyclization at the bay regions of the dihydro peri‐tetracene precursor, followed by oxidative dehydrogenation. This compound features an open‐shell singlet diradical ground state, global antiaromaticity, exceptional stability under ambient conditions, and amphoteric redox behavior with a small energy gap. Its dication also possesses an open‐shell singlet ground state, and its structure was identified by X‐ray crystallographic analysis, revealing a unique [14]annulene‐within‐[22]annulene global aromatic structure. In contrast, the dianion exhibits a closed‐shell singlet ground state. This work provides valuable insights for designing and synthesizing novel open‐shell PHs with tunable electronic structures and remarkable stability.

Exploring visitor’s satisfaction and recommendation intention at mega sporting events using the S-O-R model with host country hospitability as moderator

ABSTRACT Research question This study aims to study visitor satisfaction and recommendation intention at mega sporting events using the Stimulus-Organism-Response (S-O-R) model, with host country hospitability as a moderator. Research method Data collected from 321 respondents were analyzed through partial least squares Structural Equation Modeling (PLS-SEM), and the findings of this study revealed that visitor satisfaction is affected by the ambient conditions, amenities, and convenience of the venue. Results and Findings The findings also revealed that perceptions of price value have a modest effect on visitor satisfaction. Visitor satisfaction, in turn, significantly drives recommendation intention. The moderating role of host country hospitability presents mixed results. It enhances the positive impact of ambient conditions and convenience on visitor satisfaction but does not significantly affect the relationships between price value or amenities and satisfaction. This implies that organizers of mega sporting events should focus on creating a pleasant environment and facilitating good amenities and easy access. In addition, a host country's hospitability can enhance visitor satisfaction, particularly through a welcoming atmosphere and convenient arrangements. Implication This study contributes to the existing body of event and tourism management, specifically in the context of mega sporting event. The study's findings will help service providers and policymakers to develop more robust strategies for the future mega sporting events by enhancing the visitor satisfaction, particularly through a welcoming atmosphere and convenient arrangements.

Probing plexciton emission from 2D materials on gold nanotrenches

Probing strongly coupled quasiparticle excitations at their intrinsic length scales offers unique insights into their properties and facilitates the design of devices with novel functionalities. In this work, we investigate the formation and emission characteristics of plexcitons, arising from the interaction between surface plasmons in narrow gold nanotrenches and excitons in monolayer WSe2. We study this strong plasmon–exciton coupling in both the far-field and the near-field. Specifically, we observe a Rabi splitting in the far-field reflection spectra of about 80 meV under ambient conditions, consistent with our theoretical modeling. Using a custom-designed near-field probe, we find that plexciton emission originates predominantly from the lower-frequency branch, which we can directly probe and map its local field distribution. We precisely determine the plexcitonʼs spatial extension, similar to the trench width, with nanometric precision by collecting spectra at controlled probe locations. Our work opens exciting prospects for nanoscale mapping and engineering of plexcitons in complex nanostructures with potential applications in nanophotonic devices, optoelectronics, and quantum electrodynamics in nanoscale cavities.

Analysis of Mechanical Properties and Thermal Conductivity of Thin-Ply Laminates in Ambient and Cryogenic Conditions

It is widely known that glass–epoxy laminates are renowned for their high stiffness, good thermal properties, and economic qualities. For this reason, composite materials find successful applications in various industrial sectors such as aerospace, astronautics, the storage sector, and energy. The aim of this study was to investigate the mechanical and thermal properties of composite materials comprising two different types of epoxy resin and three different hardeners, both at room temperature and under cryogenic conditions. The samples were produced at IZOERG (Gliwice, Poland) using a laboratory hot-hydraulic-press technique. During cyclic loading–unloading tests, degradation up to a strain level of 0.6% was observed both at room temperature (RT) and at 77 K. For a glass-reinforced composite with YDPN resin (EP_1_1), the highest degradation was recorded at 18.84% at RT and 33.63% at 77 K. We have also investigated the temperature dependence of thermal conductivity for all samples in a wide temperature range down to 5 K. The thermal conductivity was found to be low and had a relative difference of up to 20% among the composites. The experimental results indicated that composites under cryogenic conditions exhibited less damage and were stiffer. It was confirmed that the choice of hardener significantly influenced both properties.

Temporal characterization of NOx and its relationship with O3 at a riverine site of Foshan

Nitrogen dioxide (NO2) is a crucial precursor of tropospheric O3. This study undertakes continuous measurements of nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) at Shishan Port (SSP), a riverine site in Foshan, China. Oxides of nitrogen (NOx = NO + NO2) exhibit a distinct seasonality, with high concentrations in winter and low concentrations in summer. The daily average concentration of NOx is 30.5 ppb, with high concentrations in the evening and morning and low concentrations in the afternoon. The variation of the total oxidant (Ox = O3 + NO2) with the levels of NOx was examined to infer the atmospheric sources of Ox as the sum of a local contribution dependent on NOx and a regional contribution independent of NOx. The local contribution predominates during low wind speed and calm weather in winter. The case analysis of a typical NO2 pollution episode affirms that the increase of NO2 at night in SSP is significantly influenced by the exhaust emissions of passing ships, atmospheric diffusion conditions and the O3 concentration generated during the day. Due to the chemical coupling of NOx and O3, along with regional transport, the levels of NOx and O3 are inextricably linked yet complicated.

Measuring nearshore waves at break point in 4D with Stereo-GoPro photogrammetry: A field comparison with multi-beam LiDAR and pressure sensors

Measuring nearshore waves remains technically challenging despite wave properties are being used in a variety of applications. With the promise of high-resolution and remotely-sensed measurements of water surfaces in four dimensions (spatially and temporally), stereo-photogrammetry applied to video imagery has grown as a viable solution over the last ten years. However, past deployments have essentially used costly cameras and optics, requiring fixed deployment platforms and hindering the applicability of the method in the field.Focusing on close-range measurements of nearshore waves at break point, this paper presents a detailed evaluation of a field-oriented and cost-effective stereo-video system composed of two GoProTM(Hero 7) cameras capable of collecting 12-megapixel imagery at 24 frames per second. The so-called ‘Stereo-GoPro’ system was deployed in the surf zone during energetic conditions at a macrotidal field site using a custom-assembled mobile tower. Deployed concurrently with stereo-video, a 16-beam LiDAR (Light Detection and Ranging) and two pressure sensors provided independent data to assess stereo-GoPro performance. All three methods were compared with respect to the evolution of the free-surface elevation over 25 min of recording at high tide and the wave parameters derived from spectral analysis. We show that stereo-GoPro allows producing digital elevation models (DEMs) of the water surface over large areas (250 m2) at high spatial resolution (0.2 m grid size), which was unsurpassed by the LiDAR. From instrument inter-comparisons at the location of the pressure transducers, free-surface elevation root-mean square errors of 0.11 m and 0.18 m were obtained respectively for LiDAR and stereo-GoPro. This translated into a maximum relative error of 3.9% and 12.5% on spectral wave parameters for LiDAR and stereo-GoPro, respectively. Optical distortion in imagery, which could not be completely corrected with calibration, was the main source of error. Whilst stereo-video processing workflow remains complex, cost-effective stereo-photogrammetry already opens new opportunities for deriving wave parameters in coastal regions, as well as for various other practical applications. Further tests should try to address specifically challenges associated to variable ambient conditions and acquisition configurations, affecting measurement performance, to guarantee a larger uptake of the technique.

Synergistic N/F Dual-Doped MoC/C Catalyst Synthesized via Liquid Phase Plasma for Sustainable Ammonia Production.

NH3 is a versatile solution for the storage and distribution of sustainable energy, offering high energy density and promising applications as a renewable hydrogen carrier. However, electrochemical NH3 synthesis under ambient conditions remains challenging, such as low selectivity and efficiency, owing to the inertness of N≡N and competing reactions. In this study, a catalyst (MoC/NFC) comprising molybdenum carbide evenly dispersed on carbon doped with N and F heteroatoms was successfully synthesized using liquid-phase plasma. The MoC/NFC catalyst exhibited a maximum NH3 yield of 115 μg h-1 mg-1cat. with a faradaic efficiency of 1.15% at -0.7 V vs reversible hydrogen electrode in 0.1 M KOH electrolyte. Pyridinic- and pyrrolic-N atoms adjacent to the carbon pores served as active sites for N2 adsorption and enabled N2 triple bond cleavage. In addition, F doping contributed to N2 activation owing to the high electronegativity of 3.98, resulting in the attraction of more electrons. These findings demonstrate a significant advancement in the development of efficient catalysts for electrochemical ammonia synthesis, potentially paving the way for scalable and sustainable NH3 production methods that can support the growing demand for renewable energy storage solutions.

Breathing effect in a Tetrapodal Lanthanide‐Phosphonate Organic Framework

The highly flexible organic linker hexamethylenediamine‐N,N,N’,N’‐tetrakis(methylphosphonic acid) (H8htp) was used in the preparation of a new 3D MOF formulated as [La2(SO4)2(H6htp)(H2O)4]∙2H2O (UAV‐15) by using hydrothermal synthesis. The flexibility of the organic linker posed a serious challenge in the preparation of crystalline materials: for this, the judicious selection of sulfuric acid to act as a mineralizing agent proved to be instrumental, acting in the retardation of the coordination of the phosphonic acid groups, as well as being an integral part the UAV‐15 by coordinating to the metal center. The material is a 3D network having channels filled with crystallization water molecules that can be easily removed by increasing of temperature (120ºC for 24h), leading to a single‐crystal‐to‐single‐crystal transformation originating [La2(SO4)2(H6htp)(H2O)3] (UAV‐15d). This transformation maintains the overall topology of UAV‐15 with only a small distortion of the framework. The reversibility of this transformation was studied, with the material reverting naturally to its original structure at ambient conditions for a period of 3 months or, in a faster way, when immersed in water at 120 ºC for 24h.

A consistent treatment of mixed‐phase saturation for atmospheric thermodynamics

AbstractIce processes are integral to the formation and maintenance of high‐level clouds and can contribute substantially to the buoyancy of deep moist convection. These processes are represented in modern microphysics parameterisations but are commonly ignored in theoretical treatments of moist thermodynamics. While many thermodynamic variables can be defined uniquely for saturation with respect to liquid water and ice, it is desirable to account for the presence of mixed‐phase condensate, which is common in real clouds. Here, a simple yet novel representation of mixed‐phase saturation is introduced. Using this approach, analytical equations are derived for a variety of thermodynamic variables under mixed‐phase conditions. These include mixed‐phase versions of the saturation vapour pressure, saturated lapse rates, isobaric wet‐bulb temperature, and equivalent potential temperature. A new formulation of the ice–liquid water potential temperature is also presented, together with a method for calculating the mixed‐phase pseudo wet‐bulb temperature and wet‐bulb potential temperature. In addition, two new thermodynamic quantities are introduced: the isobaric saturation‐point temperature, a mixed‐phase analogue of the dew‐point and frost‐point temperatures, and the lifting saturation level, a mixed‐phase analogue of the lifting condensation and lifting deposition levels. Differences between each mixed‐phase variable and its liquid‐ and ice‐only counterparts are quantified across a wide range of atmospheric conditions. A Python library for evaluating these variables, developed during the course of this work, is also briefly introduced.

Analysis of aging effects on the mechanical and vibration properties of quasi-isotropic basalt fiber-reinforced polymer composites

Eco-friendly natural fiber composites, such as basalt fiber composites, are gaining traction in material science but remain vulnerable to environmental degradation. This study investigates the mechanical and vibrational properties of quasi-isotropic basalt fiber composites subjected to aging in two different environments: ambient (30 ºC) and subzero (-10 ºC), both in distilled water until moisture saturation. Aged specimens absorbed 8.66% and 5.44% moisture in ambient and subzero conditions, respectively. Mechanical testing revealed significant strength reductions in tensile, flexural, impact, and short beam shear tests, with ambient-aged specimens showing the largest decline (up to 31.7% in flexural strength). Vibrational analysis showed reduced natural frequencies, particularly under ambient conditions (27.27%). Sound absorption tests showed that pristine specimens had the highest transmission loss, while moisture-rich ambient-aged specimens had the lowest. SEM analysis confirmed surface degradation, with fiber pull-out and matrix debonding contributing to property loss. This research provides valuable insights into the environmental limitations of basalt fiber composites, emphasizing the need for enhanced durability in eco-friendly materials.

Selective Oxidation of Polyesters via PdCu-TiO2 Photocatalysts in Flow.

Catalytic upcycling of plastic wastes offers a sustainable circular economy. Selective conversion of the most widely used polyester, polyethylene terephthalate (PET), under ambient conditions is practically attractive because of low energy consumption and carbon footprint. Here, we report selective, aerobic conversion of PET in a flow reactor using TiO2 photocatalyst modified with atomic Pd and metallic PdCu (Pd1Cu0.4-TiO2) under ambient conditions. We demonstrate that atomically synergistic Pd1Cu0.4-TiO2 exhibits a formate evolution of 4707 μmol g-1 h-1 with a selectivity of 92.3% together with trace COx released. Importantly, we show that this corresponds to 10-103 times greater activity than reported photocatalytic systems. We confirm that synergy between atomic Pd and metallic PdCu boosts directional charge transfer and oxygen-induced C-C cleavage and inhibits product decomposition. We conclude that photocatalytic waste plastic-to-chemical conversion is sustainable via targeted engineering of atomically synergistic catalysts and reaction systems.

Rapid Chemical Synthesis of High-Entropy Oxide Colloids under Ambient Conditions

Rapid Chemical Synthesis of High-Entropy Oxide Colloids under Ambient Conditions

Conduction channel creation by interstitial site engineering in otherwise insulating Na6ZnS4 for Na-conducting solid-state electrolytes

Na5.6Zn0.6Ga0.4S4, which retains the crystalline structure of its parent form Na6ZnS4, is described as a new class of Na-conducting solid-state electrolytes (SSEs) for all-solid-state batteries. We demonstrate that while Na6ZnS4 is ionically insulating (1.4 nS cm-1), Ga-substitution results in an astonishing improvement of ionic conductivity (σion) to 70.1 μS cm-1, making Na5.6Zn0.6Ga0.4S4 a practical SSE. This dramatic increase in σion (5 × 104 fold) is associated with an increased Na+ occupancy in interstitial sites as ‘x’ increases in Na6-xZn1-xGaxS4, where interstitial Na ions facilitate long-range Na+ conduction, which is otherwise immobile. Ga-substitution also results in phase-pure Na6-xZn1-xGaxS4, contributing at least partially to the enhancement of σion. Furthermore, Na6-xZn1-xGaxS4 exhibits neither releasing H2S gas nor compromising its crystalline structure for several hours under ambient conditions. Ga-substitution also enhances electrochemical stability. While the anodic limit remains largely unchanged, the cathodic limit is significantly lowered from 0.99 V vs. Na2Sn in Na6ZnS4 to 0.35 V in Na5.6Zn0.6Ga0.4S4, resulting in stable Na alloying/dealloying reactions in a symmetric Na2Sn ‖ Na2Sn cell. These findings are comprehensively supported by various experimental and theoretical methods. Finally, we construct a full cell (Na2Sn ‖ TiS2) and demonstrate the practicality of Na5.6Zn0.6Ga0.4S4 as a promising SSE in all solid-state Na ion batteries.

Visualizing Triplet Energy Transfer in Organic Near-Infrared Phosphorescent Host-Guest Materials.

Limited by the energy gap law, purely organic materials with efficient near-infrared room temperature phosphorescence are rare and difficult to achieve. Additionally, the exciton transition process among different emitting species in host-guest phosphorescent materials remains elusive, presenting a significant academic challenge. Herein, using a modular nonbonding orbital-π bridge-nonbonding orbital (n-π-n) molecular design strategy, we develop a series of heavy atom-free phosphors. Systematic modification of the π-conjugated cores enables the construction of a library with tunable near-infrared phosphorescence from 655 to 710 nm. These phosphors exhibit excellent performance under ambient conditions when dispersed into a 4-bromobenzophenone host matrix, achieving an extended lifetime of 11.25 ms and a maximum phosphorescence efficiency of 4.2 %. Notably, by eliminating the interference from host phosphorescence, the exciton transition process in hybrid materials can be visualized under various excitation conditions. Spectroscopic analysis reveals that the improved phosphorescent performance of the guest originates from the triplet-triplet energy transfer of abundant triplet excitons generated independently by the host, rather than from enhanced intersystem crossing efficiency between the guest singlet state and the host triplet state. The findings provide in-depth insights into constructing novel near-infrared phosphors and exploring emission mechanisms of host-guest materials.

A Dry Patch with In Situ Solid-to-Gel Transformation for All-in-One Skin Wound Care.

Hydrogel-based dressing materials offer significant potential in expediting skin wound healing. Nevertheless, they face several challenges: poor adhesion to wound tissues, difficulties in preservation under ambient conditions, and limited multifunctionality to support all wound healing stages. In this work, a dry patch is designed to address these persistent issues by featuring an in situ solid-to-gel transformation and Janus wet tissue adhesiveness. The HGP patch integrates a wet adhesive layer combining dopamine-conjugated hyaluronic acid (HD) and poly(acrylic acid) (PAA), a drug-loading layer comprising gelatin (Gel), and a nonadhesive gelation layer of poly(vinyl alcohol) (PVA) and sodium alginate (SA). This hierarchical structural design confers exceptional wound adhesion, hemostatic capabilities, and antibacterial and antioxidant activities, as well as immune regulatory properties. These attributes collectively support accelerated skin wound healing, particularly in cases complicated by bacterial infections. This research charts an approach to engineer hydrogel-based wound dressings through on-site hydrogel formation, thus advancing the treatment of wounds afflicted with complex infections.