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1.
Sci Total Environ ; 943: 173732, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38851348

RESUMO

BACKGROUND AND OBJECTIVES: Groundwater contamination poses a significant health challenge in India, particularly impacting children. Despite its importance, limited research has explored the nexus between groundwater quality and child nutrition outcomes. This study addresses this gap, examining the association between groundwater quality and child undernutrition, offering pertinent insights for policymakers. DATA AND METHODS: The study uses data from the fifth round of the National Family Health Survey (NFHS) and the Central Groundwater Board (CGWB) to analyze the association between groundwater quality and child nutritional status. The groundwater quality data were collected by nationwide monitoring stations programmed by CGWB, and the child undernutrition data were obtained from the NFHS-5, 2019-21. The analysis included descriptive and logistic regression model. The study also considers various demographic and socio-economic factors as potential moderators of the relationship between groundwater quality and child undernutrition. FINDINGS: Significant variation in groundwater quality was observed across India, with numerous regions displaying poor performance. Approximately 26.53 % of geographical areas were deemed unfit for consuming groundwater. Environmental factors such as high temperatures, low precipitation, and arid, alluvial, laterite-type soils are linked to poorer groundwater quality. Unfit-for-consumption groundwater quality increased the odds of undernutrition, revealing a 35 %, 38 %, and 11 % higher likelihood of stunting, underweight, and wasting in children, with higher pH, Magnesium, Sulphate, Nitrate, Total Dissolved Solids, and Arsenic, levels associated with increased odds of stunting, underweight, and wasting. Higher temperatures (>25 °C), high elevations (>1000 m), and proximity to cultivated or industrial areas all contribute to heightened risks of child undernutrition. Children consuming groundwater, lacking access to improved toilets, or living in rural areas are more likely to be undernourished, while females, higher-income households, and those consuming dairy, vegetables, and fruits daily exhibit lower odds of undernutrition. POLICY IMPLICATIONS: Policy implications highlight the urgent need for investment in piped water supply systems. Additionally, focused efforts are required to monitor and improve groundwater quality in regions with poor water quality. Policies should emphasize safe sanitation practices and enhance public awareness about the critical role of safe drinking water in improving child health.


Assuntos
Água Subterrânea , Qualidade da Água , Monitoramento Ambiental , Água Subterrânea/química , Índia/epidemiologia , Desnutrição/epidemiologia , Poluição da Água/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Concentração de Íons de Hidrogênio , Política Ambiental , Política de Saúde , Arsênio/análise , Humanos , Criança , Sulfatos/análise , Magnésio , Cloretos
2.
Chem Rec ; 24(5): e202400052, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38775236

RESUMO

The exploration of individual nanoclusters is rapidly advancing, despite stability concerns. To address this challenge, the assembly of cluster nodes through linker molecules has been successfully implemented. However, the linking of the cluster nodes itself introduces a multitude of possibilities, especially when additional factors come into play. While this method proves effective in enhancing material stability, the specific reasons behind its success remain elusive. In our laboratory, we have undertaken extensive studies on Ag cluster-assembled materials. So, here our goal is to establish a model system that allows for the discernment of various factors, eliminating unnecessary complexities during the linking approach. So, we hope that the systematic discourse presented in here will contribute significantly to future endeavors, helping to set clear priorities, and provide solutions to concerns that arise when working with a model system.

3.
Dalton Trans ; 53(23): 9657-9663, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38624154

RESUMO

The synthesis of copper (Cu) nanoclusters (NCs) has experienced significant advancements in recent years. Despite the exploration of metal NCs dating back almost two decades, challenges specific to Cu NC synthesis arise from the variable oxidation states and heightened reactivity of intermediate Cu complexes, distinguishing it from its analogous counterparts. In this study, we present a comprehensive overview of this newly evolving research domain, focusing on the synthetic aspects. We delve into various factors influencing the synthesis of Cu NCs, with specific emphasis on the role of reducing agents. The impact of the reducing agent is particularly pivotal in this synthetic process, ultimately influencing the formation of model M(0)-containing NCs, which are less readily accessible in the context of Cu NCs. We anticipate that this frontier article will pave the way for accelerated research in the field of Cu NCs. By aiding in the selection of specific reaction conditions and reducing agents, we believe that this work will contribute to a faster-paced exploration of Cu NCs, further advancing our understanding and applications in this exciting area of nanomaterial research.

4.
Phys Rev Lett ; 132(7): 076301, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38427874

RESUMO

Interferometry is a vital tool for studying fundamental features in the quantum Hall effect. For instance, Aharonov-Bohm interference in a quantum Hall interferometer can probe the wave-particle duality of electrons and quasiparticles. Here, we report an unusual Aharonov-Bohm interference of the outermost edge mode in a quantum Hall Fabry-Pérot interferometer, whose Coulomb interactions were suppressed with a grounded drain in the interior bulk of the interferometer. In a descending bulk filling factor from ν_{b}=3 to ν_{b}≈(5/3), the magnetic field periodicity, which corresponded to a single "flux quantum," agreed accurately with the enclosed area of the interferometer. However, in the filling range, ν_{b}≈(5/3) to ν_{b}=1, the field periodicity increased markedly, a priori suggesting a drastic shrinkage of the Aharonov-Bohm area. Moreover, the modulation gate voltage periodicity decreased abruptly at this range. We attribute these unexpected observations to edge reconstruction, leading to area changing with the field and a modified modulation gate-edge capacitance. These reproducible results support future interference experiments with a quantum Hall Fabry-Pérot interferometer.

5.
Eur J Neurol ; : e16234, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500270

RESUMO

BACKGROUND AND PURPOSE: Cognitive impairment is a common symptom of multiple sclerosis (MS) and occurs in more than 40% of people living with MS (plwMS). No real-world study has assessed the perception of neurologists and plwMS on cognitive issues. METHODS: Using data from the 2011-2019 Adelphi MS Disease Specific Programme database, this real-world, retrospective, cross-sectional multi-cohort study included people aged ≥18 years with relapsing-remitting MS and secondary progressive MS from the United States, UK and the EU. Neurologists provided data on the patient record form for plwMS, with the same plwMS invited to voluntarily complete a patient self-completion form: a questionnaire about their experiences with MS. RESULTS: Of 25,374 plwMS, 4817 who provided information on cognitive and mood symptoms were included in the analysis. Of the plwMS, 68% and 59% reported feeling 'mentally fatigued' and having 'difficulty concentrating', respectively. Neurologists reported only 27% of plwMS as having 'difficulty concentrating' and 15% of plwMS as having 'short-/long-term memory problems'. Neurologists reported cognitive or mood symptoms as 'not experienced' by a higher percentage of participants with relapsing-remitting MS than secondary progressive MS. Of the plwMS who experienced 'difficulty concentrating', most had a concomitant feeling of being 'mentally fatigued' (52%), followed by 'feeling anxious or tense' (49%) and 'feeling depressed' (44%). In plwMS, caregivers reported 'difficulty concentrating' (16%) as the most common cognitive issue. CONCLUSION: A clear discordance was observed between neurologists and plwMS regarding the perception of the cognitive and neuropsychiatric issues. These results underline the under-perception of cognitive and emotional affective symptoms in plwMS during neurological consultations.

6.
Org Lett ; 26(7): 1511-1516, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38358095

RESUMO

Under mechanochemical conditions in a mixer mill, Rh2(OAc)4 catalyzes the reaction between aryldiazoesters and anilines to give α-amino esters. The process proceeds under mild conditions and is insensitive to air. It is solvent-free and scalable. A broad substrate scope, short reaction times, operational simplicity, and good functional group tolerance are additional salient features of this protocol.

7.
J Phys Chem Lett ; 15(4): 947-958, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38252029

RESUMO

Photoluminescence (PL) emission is an intriguing characteristic displayed by atomically precise d10 metal nanoclusters (NCs), renowned for their meticulous atomic arrangements, which have captivated the scientific community. Cu(I) NCs are a focal point in extensive research due to their abundance, cost-effectiveness, and unique luminescent attributes. Despite similar core sizes, their luminescent characteristics vary, influenced by multiple factors. Progress hinges on synthesizing new NCs and modifying existing ones, with postsynthetic alterations impacting emission properties. The rapid advancements in this field pose challenges in discerning essential points for excelling amidst competition with other d10 NCs. This Perspective explores the intricate origins of PL emission in Cu(I) NCs, providing a comprehensive review of their correlated structural architectures. Understanding the mechanistic origin of PL emission in each cluster is crucial for correlating diverse characteristics, contributing to a deeper comprehension from both fundamental and applied scientific perspectives.

8.
Nanoscale ; 16(7): 3583-3590, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38268470

RESUMO

Atomically precise copper nanoclusters (Cu NCs), an emerging class of nanomaterials, have garnered significant attention owing to their versatile core-shell architecture and their potential applications in catalytic reactions. In this study, we present a straightforward synthesis strategy for [Cu29(StBu)12(PPh3)4Cl6H10][BF4] (Cu29) NCs and explore their catalytic activity in the carbonylative C-N coupling reaction involving aromatic amines and N-heteroarenes with dialkyl azodicarboxylates. Through a combination of experimental investigations and density functional theory studies, we elucidate the radical mechanisms at play. The crucial step in the catalytic process is identified as the decomposition of diisopropyl azodicarboxylates on the surface of Cu29 NCs, leading to the generation of oxyacyl radicals and the liberation of nitrogen gas. Subsequently, an oxyacyl radical abstracts a hydrogen atom from aniline, initiating the formation of an aminyl radical. Finally, the aminyl radical reacts with another oxyacyl radical, culminating in the synthesis of the desired carbamate product. This detailed analysis provides insights into the intricate catalytic pathways of Cu29 NCs, shedding light on their potential for catalyzing carbonylative C-N coupling reactions.

9.
J Biomol Struct Dyn ; 42(1): 461-474, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-36995127

RESUMO

Saprolegnia parasitica is an oomycete responsible for a fish disease called saprolegniosis, which poses an economic and environmental burden on aquaculture production. In Saprolegnia, CHS5 of S. parasitica (SpCHS5) contains an N-terminal domain, a catalytic domain of the glycosyltransferase -2 family containing a GT-A fold, and a C-terminal transmembrane domain. No three-dimensional structure of SpCHS5 is reported yet disclosing the structural details of this protein. We have developed a structural model of full-length SpCHS5 and validated it by molecular dynamics simulation technique. From the 1 microsecond simulations, we retrieved the stable RoseTTAFold model SpCHS5 protein to explain characteristics and structural features. Furthermore, from the analysis of the movement of chitin in the protein cavity, we assumed that ARG 482, GLN 527, PHE 529, PHE 530, LEU 540, SER 541, TYR 544, ASN 634, THR 641, TYR 645, THR 641, ASN 772 residues as a main cavity lining site. In SMD analysis, we investigated the opening of the transmembrane cavity required for chitin translocation. The pulling of chitin from the internal cavity to the extracellular region was observed through steered molecular dynamics simulations. A comparison of the initial and final structures of chitin complex showed that there's a transmembrane cavity opening in the simulations. Overall, this present work will help us understand the structural and functional basis of CHS5 and design inhibitors against SpCHS5.Communicated by Ramaswamy H. Sarma.


Assuntos
Saprolegnia , Animais , Saprolegnia/metabolismo , Fosfolipídeos , Quitina Sintase/metabolismo
10.
Sci Total Environ ; 912: 169593, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38151131

RESUMO

BACKGROUND: Frequent natural disasters like floods pose a major threat to India, with significant implications for public health. Low birth weight (LBW) is a critical global health concern, contributing to neonatal mortality. However, the association between floods and LBW remains underexplored. This study aims to address this gap by investigating the association between flood hazards and LBW in India using a geospatial approach. By analyzing data from the National Family Health Survey (NFHS-5) and flood zonation maps, the study aims to uncover the spatial dynamics of this association, offering insights into the implications of floods on birth weight across diverse geographical regions. METHODS: The study used the fifth round of NFHS data, 2019-21, which involved 202,194 children selected through a multi-stage stratified sampling technique. The Vulnerability Atlas of India 2019 maps were also utilized to classify areas as flood or non-flood zones. Birth weight data from the NFHS-5 were categorized into three groups: very low, low, and normal birth weight (VLBW, LBW and NBW). Control variables including flood exposure, socio-demographic attributes, and geographic region were considered. Bivariate analysis and multinomial logistic regression were employed for statistical analysis. The spatial analysis involved Moran's I statistics and Geographically Weighted Regression to explore spatial dynamics of the association between floods and birth weight in India. RESULTS: Floods predominantly affect India's lower Himalayan belts and western coastal regions. Flood-affected areas show higher proportions of VLBW and LBW infants. Groundwater usage and unimproved sanitation are associated with higher risk of VLBW and LBW. Sex, wealth, maternal education, residence type, and geographic region significantly influence birth weights. Multinomial logistic regression reveals 8 % and 27 % higher risks for LBW and VLBW in flood-affected regions. LISA cluster maps identify high-risk areas for both LBW and floods. Geographically Weighted Regression highlights 52 % of the variability in LBW occurrences can be attributed to the influence of flood hazards. Families hailing from the poorest wealth background and exposed to flood hazards bear a 5 % heightened likelihood of delivering LBW infants, in stark contrast to their counterparts from the same economic background yet unaffected by floods. CONCLUSIONS: The significant association between floods and LBW underscores the importance of robust disaster preparedness and public health strategies. By unraveling the spatial intricacies of flood-induced LBW disparities, this research provides valuable insights for promoting healthier birth outcomes and reducing child mortality rates, particularly in flood-prone regions. These findings emphasize the importance of holistic policies that address both environmental challenges and socioeconomic inequalities to safeguard maternal and infant health across the nation.


Assuntos
Desastres , Inundações , Recém-Nascido , Lactente , Criança , Humanos , Peso ao Nascer , Recém-Nascido de Baixo Peso , Índia/epidemiologia
11.
Protein Sci ; 33(2): e4872, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38114424

RESUMO

To survive extreme drying (anhydrobiosis), many organisms, spanning every kingdom of life, accumulate intrinsically disordered proteins (IDPs). For decades, the ability of anhydrobiosis-related IDPs to form transient amphipathic helices has been suggested to be important for promoting desiccation tolerance. However, evidence empirically supporting the necessity and/or sufficiency of helicity in mediating anhydrobiosis is lacking. Here, we demonstrate that the linker region of CAHS D, a desiccation-related IDP from the tardigrade Hypsibius exemplaris, that contains significant helical structure, is the protective portion of this protein. Perturbing the sequence composition and grammar of the linker region of CAHS D, through the insertion of helix-breaking prolines, modulating the identity of charged residues, or replacement of hydrophobic amino acids with serine or glycine residues results in variants with different degrees of helical structure. Importantly, correlation of protective capacity and helical content in variants generated through different helix perturbing modalities does not show as strong a trend, suggesting that while helicity is important, it is not the only property that makes a protein protective during desiccation. These results provide direct evidence for the decades-old theory that helicity of desiccation-related IDPs is linked to their anhydrobiotic capacity.


Assuntos
Proteínas Intrinsicamente Desordenadas , Tardígrados , Animais , Tardígrados/metabolismo , Dessecação , Proteínas Intrinsicamente Desordenadas/química , Prolina/metabolismo
12.
Nano Lett ; 23(19): 8923-8931, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37725097

RESUMO

We have synthesized and characterized a new two-dimensional honeycomb architecture resembling a single-layer of atomically precise silver cluster-assembled material (CAM), [Ag12(StBu)6(CF3COO)6(4,4'-azopyridine)3] (Ag12-azo-bpy). The interlayer noncovalent van der Waals interactions within the single-crystals were successfully disrupted, leading to the creation of this unique structure. The optimized Ag12-azo-bpy CAM demonstrates a valence band that is localized on the Ag12 cluster node situated near the Fermi energy level. This localization induces electron injection from the linker to the cluster node, facilitating efficient charge transportation along the plane. Exploiting this single-layer structure as a distinctive platform for p-type channel material, it was employed in a field-effect transistor configuration. Remarkably, the transistor exhibits a high hole mobility of 1.215 cm2 V-1 s-1 and an impressive ON/OFF current ratio of ∼4500 at room-temperature.

13.
Nanoscale ; 15(40): 16299-16306, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37718910

RESUMO

Silver cluster-assembled materials (SCAMs) have garnered significant interest as promising platforms for different functional explorations. Their atomically precise structures, intriguing chemical/physical properties, and remarkable luminescent capabilities make them highly appealing. However, the properties of these materials are primarily determined by their structural architecture, which is heavily influenced by the linker molecules used in their assembly. The choice of linker molecules plays a pivotal role in shaping the structural characteristics and ultimately determining the unique properties of SCAMs. To this end, the first SCAM with an intriguing (3,6)-connected kgd topology, [Ag12(StBu)6(CF3COO)6(TPBTC)6]n (termed TUS 3), TPBTC = benzene-1,3,5-tricarboxylic acid tris-pyridin-4-ylamide, has been synthesized by reticulating C6-symmetric Ag12 cluster cores with C3-symmetric tripodal pyridine linkers. Due to the structutural architecture of the linker molecule, TUS 3 posseses a luminescent porous framework structure where each two-dimensional (2D) layers are non-covalently linked with each other to form a three dimensional (3D) framework and ultimately offers uniaxial open channels. The compact mesoporous structural architecture not only gives the excellent surface area but also offers impressive stability of this material even in water medium. Taking advantage of these properties, TUS 3 shows brilliant catalytic activity in the reduction of hexacyanoferrate(III) using sodium borohydride in aqueous solutions.

14.
Phys Rev Lett ; 131(9): 096302, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37721820

RESUMO

The remarkable Cooper-like pairing phenomenon in the Aharonov-Bohm interference of a Fabry-Perot interferometer-operating in the integer quantum Hall regime-remains baffling. Here, we report the interference of paired electrons employing "interface edge modes." These modes are born at the interface between the bulk of the Fabry-Perot interferometer and an outer gated region tuned to a lower filling factor. Such a configuration allows toggling the spin and the orbital of the Landau level of the edge modes at the interface. We find that electron pairing occurs only when the two modes (the interfering outer and the first inner) belong to the same spinless Landau level.

15.
Nanoscale Horiz ; 8(11): 1509-1522, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37772632

RESUMO

The quest for cleaner pathways to the production of fuels and chemicals from non-fossil feedstock, efficient transformation of raw materials to value-added chemicals under mild conditions, and control over the activity and selectivity of chemical processes are driving the state-of-the-art approaches to the construction and precise chemical modification of sustainable nanocatalysts. As a burgeoning category of atomically precise noble metal nanoclusters, copper nanoclusters (Cu NCs) benefitting from their exclusive structural architecture, ingenious designability of active sites and high surface-to-volume ratio qualify as potential rationally-designed catalysts. In this Minireview, we present a detailed coverage of the optimal design strategies and controlled synthesis of Cu NC catalysts with a focus on tuning of active sites at the atomic level, the implications of cluster size, shape and structure, the ligands and heteroatom doping on catalytic activity, and reaction scope ranging from chemical catalysis to emerging photocatalysis and electrocatalysis.

16.
J Fluoresc ; 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37542589

RESUMO

In this work, we introduced a simple aggregation-induced emission enhancement (AIEE) sensor (PHCS) which can selectively detect and discriminate three environmentally and biologically imperative heavy metal ions (Cu2+, Co2+ and Hg2+) and a hazard class 1 categorized nitro-explosive picric acid (PA) in differential media. By virtue of its weak fluorescence attributes in pure organic medium owing to the synergistic operation of multiple photophysical quenching mechanisms, the molecular probe showcased highly selective 'TURN ON' fluorogenic response towards hazardous Hg2+ with a limit of detection (LOD) as low as 97 nM. Comprehensive investigation of binding mechanism throws light on the cumulative effect of probe-metal complexation induced chelation enhanced fluorescence (CHEF) effect and subsequent AIEE activation within the formed probe-metal adducts. Noteworthily, the probe (PHCS) can be readily used in real water samples for the quantitative determination of Hg2+ in a wide concentration range. In addition, the probe displayed modest colorimetric recognition performances to selectively detect and discriminate two essential heavy metal ions (Cu2+ and Co2+) with a LOD of 96 nM and 65 nM for Cu2+ and Co2+ respectively, in semi-aqueous medium. Intriguingly, based on high photoluminescence efficiency, the AIEE active nano-aggregated PHCS displayed a remarkable propensity to be used as a selective and ultra-sensitive 'TURN-OFF' fluorogenic chemosensor towards PA with LOD of 34.4 ppb in aqueous medium. Finally, we specifically shed light on the interaction of PHCS hydrosol towards PA using some unprecedented techniques, which helped uncover new photophysical insights of probe-explosive molecule interaction. We shed light on novel photophysical insights toward unique multifunctional sensory aptitude of a simple aggregation-induced emission enhancement active organic functional molecule in differential media, enabling ultra-sensitive discriminative detection of toxic heavy metal ions and explosive molecule simultaneously.

17.
Comput Biol Chem ; 106: 107933, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536229

RESUMO

This study aims to investigate the potential therapeutic application of Ixeridium dentatum (ID) in treating atopic dermatitis (AD) through network pharmacology, molecular docking, and molecular dynamic simulation. We employed GC-MS techniques and identified 40 bioactive compounds present in the ID and determined their targets by accessing public databases. The convergence of compounds and dermatitis related targets led to the identification of 32 common genes. Among them, IL1B, PTGS2, IL6, IL2, and RELA, were found to be significant targets which were analyzed using Cytoscape network topology. The KEGG pathway evaluation revealed that these targets were significantly enriched in the C-type lectin receptor signaling pathway. The therapeutic efficacy of Stigmasta-5,22-dien-3-ol, Urea, n-Heptyl-, and 3-Epimoretenol was demonstrated in molecular docking assay, as evidenced by their presence in the core compounds of the compound-target network. Furthermore, these compounds exhibited significant kinetic stability and chemical reactivity in DFT quantum analysis when compared to their co-crystallized ligands and reference drug, indicating their potential as key targets for future research. Among the top three docking complexes, namely IL6-3-Epimoretenol, and IL2- Stigmasta-5,22-dien-3-ol, both demonstrated exceptional dynamic characteristics in molecular dynamics simulations at 100 ns. The feasibility of these compounds could be attributed to the prior traditional interrelationship between ID and AD. Overall, this research elucidates the interplay between AD-associated signaling pathways and target receptors with the bioactive ID. The proposal posits the utilization of antecedent compounds as a substitute for the customary pharmaceutical intervention that obstructs the discharge of cytokines, which incite dermal inflammation in the C-type lectin receptor signaling pathway of atopic dermatitis.


Assuntos
Dermatite Atópica , Medicamentos de Ervas Chinesas , Humanos , Dermatite Atópica/tratamento farmacológico , Interleucina-2 , Interleucina-6 , Simulação de Acoplamento Molecular , Lectinas Tipo C
18.
Chem Commun (Camb) ; 59(61): 9336-9339, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37404125

RESUMO

This article explores the challenges in synthesizing highly symmetric Cu(I)-thiolate nanoclusters and reports a nested Keplerian architecture of [Cu58H20(SPr)36(PPh3)8]2+ (Pr = CH2CH2CH3). The structure is made up of five concentric polyhedra of Cu(I) atoms, which create enough space to accommodate five ligand shells all within a range of 2 nm. This fascinating structural architecture is also linked to the unique photoluminescence properties of the nanoclusters.

19.
Nanoscale ; 15(29): 12227-12234, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37378425

RESUMO

Silver cluster-assembled materials (SCAMs) are emerging light-emitting materials with molecular-level structural designability and unique photophysical properties. Nevertheless, the widespread application scope of these materials is severely curtailed by their dissimilar structural architecture upon immersing in different solvent media. In this work, we report the designed synthesis of two unprecedented (4.6)-connected three-dimensional (3D) luminescent SCAMs, [Ag12(StBu)6(CF3COO)6(TPEPE)6]n (denoted as TUS 1), TPEPE = 1,1,2,2-tetrakis(4-(pyridin-4-ylethynyl)phenyl)ethene and [Ag12(StBu)6(CF3COO)6(TPVPE)6]n (denoted as TUS 2), TPVPE = 1,1,2,2-tetrakis(4-((E)-2-(pyridin-4-yl)vinyl)phenyl)ethene, composed of an Ag12 cluster core connected by quadridentate pyridine linkers. Attributed to their exceptional fluorescence properties with absolute quantum yield (QY) up to 9.7% and excellent chemical stability in a wide range of solvent polarity, a highly sensitive assay for detecting Fe3+ in aqueous medium is developed with promising detection limits of 0.05 and 0.86 nM L-1 for TUS 1 and TUS 2 respectively, comparable to the standard. Furthermore, the competency of these materials to detect Fe3+ in real water samples reveals their potential application in environmental monitoring and assessment.

20.
Acc Chem Res ; 56(13): 1838-1849, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37357739

RESUMO

ConspectusUnderstanding the structural architecture of nanoparticles is essential for investigating their fundamental properties because these materials have become more desirable in modern nanoscience research. Designing a proper synthetic strategy to control their growth with atomic precision is crucial. The polydispersed nature of the nanoparticles makes determining their precise structural information challenging. Metal nanoclusters (NCs) have emerged as a promising solution to this problem as they bridge the gap between metal nanoparticles and discrete molecular complexes. Well-ordered molecular structures provide opportunities to look at structure-property correlations and find quantum confinement effects at the atomic level that reveal their similarity to molecular-like properties. While most M(0)/(I)-based NCs exhibit exceptional photoluminescence (PL) emission at room temperature, M(I)-based NCs are less likely to exhibit PL emissions due to their electronic environment. Developments in the field of metal nanoparticles have made it intriguing to achieve room-temperature PL emission in M(I) NCs. Efforts have focused on developing efficient methods for preparing luminescent M(I) NCs to better comprehend fundamental aspects of their PL emission properties. We provide an overview of various synthetic strategies for preparing NCs and their selective functionalization for generating room-temperature PL emissions. Our focus has been creating an Ag(I) NC with a core-shell architecture, as this unique structural design complements the charge transition phenomenon. The molecular structure obtained from single-crystal X-ray diffraction (SCXRD) and associated theoretical calculation revealed that our effort results in a unique hexagonal closed pack core and Keplerate shell containing [S@Ag50S12(StBu)20]4+ NC where the charge transition between the core and the metal-ligand shell facilitates emission properties. We also explored the approach of host-guest supramolecular adduct formations to engineer the surface of ligands that reduce nonradiative relaxation rates by restricting surface molecular vibrations and controlling the generation of PL emission. To do this, we capped precisely structured [Cl@Ag16S(S-Adm)8(CF3COO)5(DMF)3(H2O)2]·DMF with ß-cyclodextrin via adamantane moieties. We also describe the effects of bimetallic cluster formation on increasing surface rigidity and modulating the frontier molecular orbital arrangement, which helps to attain synergy to generate room-temperature PL emission. We focused on the structural integrity of Ag(I) NCs, allowing us to incorporate heterometal atoms at peripheral positions that lead to the formation of [CO2@Ag20Cu2S2(StBu)10(CF3COO)8(DMA)4]·(DMA). We also explored the impact of introducing extra ligands into the Ag(I) cluster node on the generation of PL emission at room-temperature. These strategies are not limited to Ag NCs. We discussed the possibility of combining core-shell architecture and surface modifications to enhance PL emission in [Cu18H3(S-Adm)12(PPh3)4Cl2] NC at room temperature. SCXRD studies revealed its distinct core-shell architecture that ensures electronic transitions and that transition is controlled by the imposed surface rigidity that yields a higher PL emission. We believe that this innovative structural engineering holds potential for the advancement of NC research, and this Account will inspire the scientific community to synthesize functional M(I) NCs.

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