Organic Groups Research Articles

Improvement of the Abrasion and Corrosion Resistance of a Waterborne Epoxy Coating by α-ZrP@PTA-Ce(III) with Dual Corrosion Inhibition Effects.

The introduction of poly(tannic acid) (PTA) and cerium ion [Ce(III)] on the surface of α-zirconium phosphate (α-ZrP) endowed the α-ZrP@PTA-Ce(III)/waterborne epoxy composite coating with enhanced corrosion protection and wear resistance performances. The successful preparation of α-ZrP@PTA-Ce(III) was confirmed through X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectra. PTA improved the compatibility between α-ZrP@PTA-Ce(III) and the waterborne epoxy resin due to the presence of organic groups from tannic acid. The wear resistance test indicated that the incorporation of α-ZrP@PTA-Ce(III) effectively reduced the coefficient of friction and the wear rate. Electrochemical impedance spectroscopy was used to analyze the corrosion protection performance of unbroken coatings and the self-healing ability of scratched coatings. The incorporation of α-ZrP@PTA-Ce(III) improved the protection performace distinctly. In addition, α-ZrP@PTA-Ce(III) endowed the composite coating with dual corrosion inhibition effects, originating from the PTA film, to prevent the penetration of corrosive media and a dense film that came from the Ce(III) cation. The waterborne epoxy system with enhanced corrosion and wear resistance in this paper broadens the application of α-ZrP.

The geochemical and thermodynamic characteristics of waste sand reinforced by microbially induced calcium carbonate precipitation

To achieve efficient utilization of waste sand and make it a recyclable resource, the waste sand was reinforced by microbially induced calcium carbonate precipitation (MICP). Scanning Electron Microscopy (SEM)–Energy Dispersive Spectrometer (EDS) and Fourier Transform Infrared Spectroscopy (FTIR) were performed to determine the mineral morphologies and elemental compositions. The results of SEM showed that rhombohedral and dumbbell-shaped minerals filled the pores of the sand column, and the elemental compositions were C, O, Ca, Al, and P. Various organic functional groups were discovered by FTIR. Mineral compositions were analyzed by X-ray diffraction (XRD). The results showed that the mineral components were calcite and aragonite, and the crystallinity of calcite improved with the increase in the bacterial concentrations. Stable carbon isotope analyses showed that the sand columns at different bacterial concentrations ranged from − 18.9 ‰ to − 21.4 ‰, which were more negative than chemical calcite with − 10.9 ‰. The mechanical properties of compression strength and splitting tensile strength proved that MICP could enhance the strength of sand columns. Thermodynamic characteristics were carefully investigated using thermogravimetric analysis from 50 °C to 1000 °C, which showed that the activation energy and thermal stability of the sand columns reinforced by MICP increased. Therefore, this study provides important insights into the process of MICP, which has good spontaneity, ecological performance, and low energy consumption. It is conducive to the construction of ecological civilization and the requirements of green development, and it has important engineering significance.

Comparative antioxidant and antimicrobial activities of Nigella sativa flower, leaf, stem, and seed derived silver nanoparticles

This study was aimed to synthesize biogenic silver nanoparticles (AgNPs) using Nigella sativa (N. sativa) plant extracts as bio-reductant. The fabricated nanoparticles were characterized by UV–visible, FTIR, and XRD. The extracts and AgNPs were then evaluated for their antioxidant and antimicrobial potentials using DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay and agar well diffusion assay correspondingly. The color change from pale yellow to tan brownish confirmed the fabrication of nanoparticles. The broad peak from 420 to 430 in the UV–Visible spectrum also confirmed AgNPs formation. In XRD spectrum the peaks indices (111), (200), (220), and (311) belonging to 2θ values of 38.101, 44.370, 64.179, and 77.549 indicated the presence of silver crystals (JCPDS file no. 00-001-1167). The presence of organic functional groups in the FTIR spectra confirmed the involvement of plant phytochemicals in fabrication of nanoparticles. Comparatively strong antioxidant potential was recorded for silver nanoparticles in comparison to parental extract. The lowest IC50 recorded was in the case flower based AgNPs was 70 µl where it corresponding crude extract resulted in IC50 of 910 µl. Highest IC50 was recorded for stem extract based NPs (100 µl). The antifungal potential of AgNPs from flower was high (24 mm) and that of the stem extract-based NPs was low (19 mm) whereas the antibacterial potential of the stem and seed extract-based extract was comparable however, the leaf and flower-based extract-based NPs were also, substantial. It was concluded from the results that all the whole Nigella sativa plant contained the reductant phytochemicals which be effectively used to fabricate NPs of the desired sizes. The fabricated NPs also exhibited good antioxidant and antimicrobial properties and can be considered as alternative drugs subjected to further verifications of the results in animal model.

Oxadiazolines as Photoreleasable Labels for Drug Target Identification.

Photoaffinity labeling is a widely used technique for studying ligand-protein and protein-protein interactions. Traditional photoaffinity labels utilize nonspecific C-H bond insertion reactions mediated by a highly reactive intermediate. Despite being the most widely used photoaffinity labels, diazirines exhibit limited compatibility with downstream organic reactions and suffer from storage stability concerns. This study introduces oxadiazolines as innovative and complementary photoactivatable labels for addition to the toolbox and demonstrates their application in vitro and through in cellulo labeling experiments. Oxadiazolines can be easily synthesized from ketone moieties and cleaved with 302-330 nm light to cleanly liberate a diazo reactive moiety that can covalently modify nucleophilic amino acid residues. Notably, oxadiazolines are compatible with various organic reaction conditions and functional groups, allowing for the exploration of a large chemical space. Several known inhibitors featuring the oxadiazoline functionality were prepared without affecting their binding affinity. Furthermore, we confirmed the ability of oxadiazolines to form covalent bonds with proteins upon UV-irradiation, both in vitro and in cellulo, yielding comparable results to those of the matched diazirine compounds.

Study on dynamic variation of acid-base properties of coal and its influence on environment during oxidation and heating

ABSTRACT The spontaneous combustion of coal poses a serious threat to production and environmental safety. Currently, scholars have conducted extensive research on the mechanisms and prevention methods of coal spontaneous combustion. However, these studies have not sufficiently addressed the changes in coal’s acid-base properties during combustion and their impact on environmental pH balance. This gap hinders a comprehensive understanding of coal combustion and precise fire suppression. This study focuses on the changes in the acid-base properties of coal during critical periods of spontaneous combustion prevention. The results showed that as the temperature increased, BJG becomes more alkaline, with a pH of 8.08 at 75°C, while HLS becomes more acidic, with a pH as low as 5.14. The aqueous solutions mainly contained SO4 2-, CO3 2-, and HCO3 −, with the SO4 2- concentration in HLS being about 200 times higher than in BJG. Additionally, this study innovatively analyzed the impact of organic substances on the acid-base properties of coal. It was found that the content of organic groups, mainly -COOH, increased by over 300%. However, the influence of pyrite is greater than that of organic acids and CO2. Furthermore, the consumption of H+ by minerals significantly reduces the acidity of the solution.

324 Use of organoids as in vitro model to study intestinal function

Abstract Organoids are tridimensional structures cultured in the lab from stem cells. Organoids have been developed for many different organs, particularly those with Lgr5+ stem cells. The organs of the digestive system belong to this group of organs and to date, organoids have been established from all the digestive tract tissues and organs including liver, gall bladder and pancreas. Although most protocols to generate organoids have focused on human and mouse organs, organoids from domestic and production animals like dogs, cats, rabbits, pigs, chickens, turkeys, and horses are actively used in research. In this presentation, the principles of developing intestinal organoids will be covered, along with a summary of how they have been used to address intestinal function and disease in our lab and by others. In our lab, we use swine enteroids (intestinal organoids) to study the intestinal epithelial responses to nutrients and pathogens. We have explored differential responses of the intestinal epithelium to organic and inorganic sources of dietary zinc, and we are currently investigating the mechanism of pathogenesis of Lawsonia intracellularis, the causative agent of porcine intestinal adenopathy. We will also discuss methods for modeling intestinal physiology using enteroids, and the advantages and challenges of working with swine enteroids.

A combined multilevel computational and experimental approach for interfacial screening and mechanical reinforcement of basalt fiber/polyamide 66 composites

Silane coupling agents (SCAs) can improve fiber-resin interface issues, yet selecting an appropriate SCA experimentally is resource-intensive. Herein, a multi-level screening method combining simulation and experiments is proposed to identify SCA-enhancing bonding between SCAs and polyamide 66 (PA66) and the basalt fiber (BF) −PA66 interface. SCAs with organic groups composed of N and O exhibited superior interaction with PA66 due to the more pronounced negative and positive electrostatic potential (ESP) distributions. In SCAs-grafted BF-PA66 models, SCAs not only altered BF surface nanostructure but also changed the arrangement of PA66 main chains from parallel to interpenetrating BF surface atoms. Besides, (3-ureapropyl)trimethoxysilane (SCA6) significantly improved BF-PA66 bonding, which was experimentally validated by enhanced interlaminar shear and mechanical properties. O atoms on SCA6 and PA66 are more electronically bound and have the smallest ESP extremum, providing strong polar interaction sites. Additionally, both simulations and experiments demonstrated a transformation from adhesive to cohesive failure.

Variation in oxidative potential of fine particulate matter and its association with chemical constituents at a regional site in India

Fine particulate matter (PM2.5) constituents are greatly affected by site-specific emission sources and are one of the main reasons for oxidative stress that leads to cardiovascular ailments. This study investigated the temporal, seasonal, and episodic variations in the oxidative potential (OP) of PM2.5 and its association with chemical components. Additionally, we have also examined the effect of filter substrates on OP. Dithiothreitol (DTT) and ascorbic acid (AA) acellular assays were used to estimate the formation of reactive oxygen species (ROS) in PM2.5 samples collected over a year from a regional site in India. PM2.5 morphology and functional groups were also analyzed. Results showed that OPDTTv was at the highest in winter (2.56 ± 0.84 nmol min−1 m−3) and at the lowest during monsoon (0.79 ± 0.65 nmol min−1 m−3). OPAAv exhibited the highest activity in post-monsoon (0.09 ± 0.04 nmol min−1 m−3) and least in summer (0.05 ± 0.04 nmol min−1 m−3). Biomass burning (BB) and open-field burning of crop residue during the rabi and kharif harvesting seasons were associated with significantly elevated PM2.5 toxicity, which is indicative of the contribution of combustion-derived particles. OPDTTv and OPAAv levels from BB in post-monsoon were 21 % and 67 % higher than the levels observed during BB in summer. Flaky irregular agglomerates and porous structures were observed during the BB period. Fourier-transformed infrared spectroscopy revealed that traffic-emitted organic hydrocarbons CH functional group was dominant across the season. Further, chemical species such as organics (OC and EC fractions) and ions (SO42−, NH4+, Cl−, NO3−) were found to be significantly associated with OP. Among the three filter substrates, the Teflon showed higher OP variability for both assays. This study emphasizes the impact of regional toxic aerosols across seasons and during episodic events. It contributes to our understanding of the toxicity of ambient PM2.5, which is crucial for developing targeted air-quality management strategies.

Changes in Soil Aggregate Carbon Components and Responses to Plant Input during Vegetation Restoration in the Loess Plateau, China.

Vegetation restoration is an effective measure to cope with global climate change and promote soil carbon sequestration. However, during vegetation restoration, the turnover and properties of carbon within various aggregates change. The effects of plant source carbon input on surface soil and subsurface soil may be different. Thus, the characteristics of carbon components in aggregates are affected. Therefore, the research object of this study is the Robinia pseudoacacia forest located in 16-47a of the Loess Plateau, and compared with farmland. The change characteristics of organic carbon functional groups in 0-20 cm, 20-40 cm, and 40-60 cm soil layers were analyzed by Fourier near infrared spectroscopy, and the relationship between the chemical structure of organic carbon and the content of organic carbon components in soil aggregates was clarified, and the mechanism affecting the distribution of organic carbon components in soil aggregates was revealed in the process of vegetation restoration. The results show the following: (1) The stability of surface aggregates is sensitive, while that of deep aggregates is weak. Vegetation restoration increased the surface soil organic carbon content by 1.97~3.78 g·kg-1. (2) After vegetation restoration, the relative contents of polysaccharide functional groups in >0.25 mm aggregates were significantly reduced, while the relative contents of aromatic and aliphatic functional groups of organic carbon were significantly increased. The opposite is true for aggregates smaller than 0.25 mm. (3) With the increase in soil depth, the effect of litter on organic carbon gradually decreased, while the effect of root input on the accumulation of inert carbon in deep soil was more lasting.

Facile and scalable synthesis of N-doped carbon based Ni electrocatalyst for efficient CO2 reduction to CO

Electrochemical reduction of CO2 into valuable chemical products could be realized by reasonable design of effective electrocatalysts with atomically dispersed active sites, but the task presents challenges for chemistry because of the lack of facile and scalable synthetic route. Therefore nitrogen-doped porous carbon supported Ni electrocatalyst is presented via a facile synthetic method. In the first step, commercial carbon black was oxidized by HNO3 to generate organic group followed by absorption of Ni ions. Secondly, calcination under NH3 atmosphere led to N doped carbon based Ni catalyst which exhibited excellent catalytic performance with approximate 95 % Faradaic efficiency for CO, which is helpful for chemists to reasonable design and scalable preparation of economical and efficient catalysts.

Application of Metal Oxides Nanoparticles to Enhance Ultraviolet Light Resistance of Polyvinyl Chloride Films

Polyvinyl chloride (PVC) films were chemically modified by including organic groups, amino group of ethylenediamine (en), and furtherly treated with aromatic aldehyde. The modification process included synthesizing the films by casting utilizing tetrahydrofuran (THF) as the solvent. The films were enriched with five metal oxide nanoparticles (NPs), specifically: TiO2, Co2O3, Cr2O3, NiO and CuO, in order to enhance their resistance to photodegradation. The films were subjected to UV light. The resulting damage was assessed both analytically and morphologically. The methods used for examination of the chemical structure comprised FT-IR, 1H-NMR, and 13C-NMR spectroscopies. SEM and AFM were utilized to test the morphology of polymeric films. The efficiency of the modified PVC films to resist UV light was assessed by measuring the roughness factor (Rq) of the irradiated PVC films. The incorporation of NPs into the modified PVC resulted in films with high resistance to UV light, as confirmed by FT-IR spectroscopy and weight loss measurement. The film made from modified PVC/Schiff base CuO NPs showed superior resistance to photo-degradation, as evidenced by the findings obtained from FT-IR spectra, surface morphological analysis, and weight loss.

Preparation and adsorptive performance study of amino modified-crosslinked composite aerogel for VOCs in wooden furniture

Abstract There is a lack of standards for harmful VOC substances in furniture products in China, and furniture’s peculiar smell is still a hot concern for society. Amino modified-crosslinked composite aerogel was prepared using a modified sol-gel method by incorporating chitosan and inorganic silica as the inorganic phase, and it was added to polyurethane coating (PU paint) and wooden substrate. Results indicated that the prepared amino modified-crosslinked composite aerogel had a pore size of 12 μm to 16 μm, retaining the lightweight structure and mesoporous characteristics of the gel while containing the active organic groups of chitosan. It exhibited a certain adsorption capacity for VOCs in both PU paint and wooden substrate, with the highest adsorption efficiency observed in fir, reaching 72.86%. These results demonstrate the feasibility of this method and suggest a new approach to pollution prevention and control in wooden furniture. It holds promising potential for scalable applications.

Progress in Application of Silane Coupling Agent for Clay Modification to Flame Retardant Polymer.

Polymer composites are widely used in various fields of production and life, and the study of preparing environmentally friendly and flame retardant clay/polymer composites has gradually become a global research hotspot. But how to efficiently surface modify clay and apply it to the field of flame retardant polymers is still a potential challenge. One of the most commonly used surface modification methods is the modification of clay with silane coupling agents. The hydrolysable groups of the silane coupling agent first hydrolyze to generate hydroxyl groups. These hydroxyl groups then undergo a condensation reaction with the hydroxyl groups on the surface of the clay, allowing for organic functional groups to be grafted onto the clay surface. The organic functional groups and polymer matrix react to generate chemical bonds so that the composite material's interface is more closely combined. Thus, the dispersion of clay in the organic polymer material and the compatibility of the two is better, which improves the flame retardant effect of the composite material. This paper introduces the classification of a silane coupling agent and the mechanism and process of silane coupling agent-modified clay, outlines the mechanism of silane coupling agent-modified clay flame retardant polymers, reviews the research results on flame retardant polymers of various clays after surface treatment with silane coupling agents in recent years, and highlights the synergistic flame retardant effect of clay and flame retardant organized by silane coupling agents. Finally, it is found that the current research in the field of silane coupling agent-modified clay in flame retardants is focused on the modification of montmorillonite, sepiolite, attapulgite, and kaolinite by KH-550, KH-560, and KH-570, and the development trends in this field are also prospected.

A study protocol for a randomized clinical trial on exposure and effects of pesticides consumption - the PEST-EXPO Brazil study

Randomized clinical trials are considered the gold standard for studies with dietary interventions, which is mainly due to the fact that they can establish causal relationships between food exposure and body composition measures or biomarkers. The aim of this study was to describe the details of a double-blind, randomized, clinical trial protocol to identify, characterize and evaluate the effects of human dietary exposure to pesticide residues in food. Specific aspects of planning (development of a research question, determination of objectives, selection of participants, randomization and blinding) and performance (recruitment of participants, measures to improve adherence, data collection, follow-up and evaluation of results) are addressed in this study. The study design proved effective in characterizing dietary patterns with foods originating from both conventional and organic agriculture. A total of 148 individuals were recruited for the study. The conventional group was represented by 47 % of the sample and the organic group was represented by 53 %. The practice of evidence-based nutrition has demanded that trials be well designed and systematically performed in the field of clinical nutrition. Therefore, this clinical trial emphasizes the importance of improving studies with toxicological nutrition that assess sources of exposure through food.•This double-blind, randomized clinical trial details the protocol for identifying, characterizing, and evaluating the effects of dietary exposure to pesticide residues.•The protocol demonstrates that well-designed and systematically conducted trials emphasize the importance of robust methodologies in evidence-based nutrition.•In the face of the global climate crisis, this clinical trial underscores the importance of enhancing studies in toxicological nutrition, particularly those evaluating sources of exposure through food, to better understand the dietary impacts on health.

Photothermal therapy and cell imaging tracking of porous silicon nanoparticle by magnesiothermic reduction and surface modification

The synthesis of silicon nanoparticles (PSi NPs) from silica nanoparticles (SiO₂) via magnesium (Mg) reduction is a promising technique due to its simplicity and cost-effectiveness. In this study, silica is utilized as the primary precursor and is subjected to a reduction process using magnesium powder as the reducing agent. By covalently attaching Fluorescein Isothiocyanate (FITC) to the surface of PSi NPs, we aim to enhance their fluorescence intensity and stability while also improving their surface reactivity and biocompatibility. The modified PSi NPs system was characterized using various microscopic techniques, Raman spectra, porosity and morphology analysis, Zeta potential, and analysis of organic functional groups to confirm successful conjugation and to evaluate changes in surface morphology, fluorescence properties, and colloidal stability. By leveraging the inherent photothermal conversion efficiency of PSi NPs, we explore their capacity to generate localized heat upon near-infrared (NIR) light irradiation, effectively inducing cancer cell apoptosis. Concurrently, the natural fluorescence of PSi NPs is harnessed to enable high-resolution imaging, facilitating real-time tracking and monitoring of therapeutic processes. The PSi NPs were subjected to a series of in vitro experiments to assess their photothermal efficiency, cytotoxicity, and imaging capabilities. Results demonstrate that PSi NPs exhibit excellent photothermal effects, leading to significant cell death in targeted cancer cells upon NIR exposure, while their fluorescence properties provide clear and detailed imaging. These findings highlight the potential of PSi NPs as multifunctional agents in cancer therapy, combining effective photothermal treatment with non-invasive imaging, thereby enhancing the precision and efficacy of therapeutic interventions.

Enhancing the uranium (VI) adsorption performance of phosphoric acid functionalized porous silica by controlled introduction of phosphoric acid group

The post-grafting of porous silica with organic group is a common method for the synthesis of organo-functionalized silica adsorbent. However, this method usually produces adsorbents with limited adsorption performances due to the pore blocking caused by the irregular introduction of organic group. In this work, we report the controllable synthesis of phosphoric acid functionalized porous silica adsorbent based on the co-condensation method for uranium (VI) adsorptive removal with enhanced adsorption performance. Characterizations of the obtained silica verify its porous structure and confirm the homogeneous distribution of phosphoric acid groups inside the silica. This silica is able to efficiently remove 98 % of uranium from a 100 mg/L uranium (VI) solution within 10 min at a dosage of 0.6 g/L and the maximum uranium (VI) adsorption amount reaches 509 mg/g. Both adsorption capacity and adsorption rate of this silica are superior than that of the silica synthesized based on conventional post-grafting method. Moreover, this silica can be reused for five times with uranium (VI) removal efficiency above 95 % and it is well applied in adsorption column for dynamically adsorptive removal of uranium (VI) from real nuclear wastewater. Mechanism-related investigations reveal that uranium (VI) adsorption on this silica proceeds by effective ion exchange of uranium (VI) ion with either phosphoric acid or silanol group and the formation of uranyl phosphonate or uranyl silicate complex. This work provides a feasible strategy to synthesize functionalized porous silica without significant pore blocking, and demonstrates the enhancement effect of regulating surface adsorption groups on the adsorption performances of porous silica. Besides, this work offers a promising adsorbent for efficient treatment of uranium-containing nuclear wastewater and reveals the mechanism of uranium adsorption on those silica adsorbent containing phosphoric acid, thiol or thioether group.

Preparation of isoreticular MIL-101(Cr) based on pre- and post-synthetic strategy and study for carbon dioxide capture

The functionalization of MIL-101(Cr) presents a formidable challenge when employing covalent bonds, due to the inherent difficulty of incorporating reactive organic groups into its structure. In this work, we have successfully synthesized MIL-101-CHO tagged with formyl by adopting a pre-synthetic strategy, utilizing 3‑hydroxy-1-oxo-1,3-dihydroisobenzofuran-5-carboxylic acid as the key ligand. Then the integrity of the formyl group and the phase purity of the resulting MIL-101-CHO were rigorously confirmed through FT-IR and 1H NMR characterization. Employing post-synthetic strategy, four amine-MOFs were prepared through cascade reaction of Schiff-base condensation and NaBH4 reduction. The CO2 adsorption properties of all isoreticular MIL-101(Cr) materials were thoroughly investigated. Notably, MIL-101-TAEA demonstrated exceptional performance, with the highest Qst 70.1 kJ/mol at low coverage, the best adsorption capability 2.34 mmol/g at 298 K under 1 bar CO2, and the selectivity 172 for CO2/N2. Furthermore, the good regenerability of MIL-101-TAEA was proved by the CO2 temperature swing adsorption tests. Ultimately, MIL-101-TAEA maintain 60 % performance for trace CO2 capture after 16 cycles under the mimic atmosphere conditions, showing its potential for practical applications in gas separation and capture technologies.

New lead-freeIodoantimonatehalide semiconductor: Synthesis, Structural characterization, DFT calculations, Hirshfeld surface, Thermal behavior, vibrational and optical properties

Hybrid metal halides have captured broad interest in the lighting and display fields because of their unique electronic structures and splendid broadband emission properties. Organic chiral building blocks can control light, charge, and spin interconversion in hybrid crystalline semiconductors with metal-halide.Based on the chiral organic molecules(S)-1-phenylethylamine, we synthesized new chiral antimony halidewith zero-dimensional structure((S)-C8H12N)4Sb2I10. Atroom temperature, the title compound is crystallized in the monoclinic P21with Z = 2 and the following unit cell dimensions: a = 12.69129 (15) Å, b = 14.96770 (15) Å, c = 13.91397 (16) Å, and β = 92.2735 (11)°.The crystal structure of this compound is composed of two crystallographically independent [Sb2I10]4- unit and four (S)-1-phenylethylammonium per unit cell. The crystal packing is governed by NH....I hydrogen bonds.Intermolecular interactions seen in the grown single crystal are studied by Hirshfeld surface and 2-D fingerprint plot.In addition to study the weak interaction a visualized approach known as RDG has been carried out.The recorded infrared IR and Raman studies confirm vibrational modes for organic and inorganic groups at room temperature in the 500–4000 cm−1 and 50–4000 cm−1 frequency regions, respectively.The optimized molecular structure and vibrational frequencies were calculated by the Density Functional Theory (DFT) method using the B3LYP level employing a LANL2DZbasis set.The title compound reveals thermal stability up to 190 °C.The opticalabsorption measurement confirms the semiconductor nature with a band gap of around 3.74 eV. The frontier molecular orbital analysis HOMO-LUMOof molecule were studied.

Physicochemical Characterization of Religious Burning Aerosols in Lhasa on the Qinghai‐Tibet Plateau

AbstractReligious burning (RB) has been identified as a major source of atmospheric aerosols on the Qinghai‐Tibet Plateau. However, there is limited understanding of the detailed chemical composition, size distribution, and optical properties of RB aerosols in this region. To characterize these important aerosol properties, ambient PM2.5 and size resolved aerosols from RB emissions in Lhasa were collected during summer 2019. Organic functional group (OFG) and inorganic ion composition was measured using Fourier transform infrared spectroscopy and ion chromatography, respectively. The ambient PM2.5 was dominated by organic components, with the OFG concentrations significantly higher during religious events, reflecting the substantial impact of RB emissions on local air quality. The RB aerosols were characterized by high fractions of alkane (34%), hydroxyl (29%), and carboxylic acid (13%) groups, with peak mass in the accumulation mode (0.56–1.00 μm). The high abundance of hydroxyl group and the size distribution pattern suggested that the RB aerosols were formed from volatilization of fuel materials followed by unaltered condensation, a process that may be unique to the low‐temperature, low‐oxygen burning in the scattered burners at the temples. The absorption coefficient of RB aerosols showed similar size distribution to the mass size distribution, but the absorption Ångström exponent displayed the lowest value in the 0.56–1.00 μm size mode. This specific size distribution aligned with the mass fraction of carboxylic acids and mirrored the mass proportion of alkanes, suggesting that smaller and larger particles were enriched with substances that have higher light‐absorbing capabilities.

Strain-Induced Structural Rearrangement Towards a White-Light-Emitting Adamantane-Type Cluster Dimer.

Group 14/16 adamantane-type hybrid clusters of the type [(RT)4E6] (T=group 14 element, E=group 16 element, R=organic group) have been reported to emit white-light when irradiated in an amorphous state with a continuous-wave (CW) infrared laser diode. This effect is enhanced if the cluster core is varied from a binary to a more complex composition. To further explore this phenomenon, we synthesized clusters with a multinary R/R'-T/T'-E/E' composition, including isolobal replacement of E with CH2, in [(2-NpSi){CH2Sn(S)Ph}3] (1, Np=naphthyl). When expanding one of the CH2 moieties to a C2H4 group, thus generating a R/R'-T/T'-E/E'/E'' cluster composition, we unexpectedly observed a dimerization of the initially formed, yet non-isolable adamantane-like cluster [(2-NpSi){CH2Sn(S)Ph}2{C2H4Sn(S)Ph}] (2) to [(2-NpSi){CH2Sn(S)Ph}2{C2H4Sn(S)Ph}]2 (3), exhibiting a heretofore unprecedented cluster architecture. Both monomeric 1 and dimeric 3, show white-light emission as thin films. The nonlinear optical response of the compounds was also modelled with DFT methods.