0000000001318936

AUTHOR

Alice Sciortino

showing 41 related works from this author

One-pot synthesis of graphene quantum dots and simultaneous nanostructured self-assembly via a novel microwave-assisted method: impact on triazine re…

2018

One-step methods for fabricating green materials endowed with diverse functions is a challenge to be overcome in terms of reducing environmental risk and cost. We report a fast and easy synthesis of multifunctional materials composed of only fluorescent dots with structural flexibility and high sorption capability. The synthesis consists of a one-pot microwave-assisted reaction for the simultaneous formation of graphene quantum dots (GQDs) from organic precursors and their spontaneous self-assembly forming porous architectures. The GQD-assemblies are robust and no signs of degradation were observed with most organic solvents. The ensuing GQDs and their porous solids were fully characterized…

Materials scienceChemical substanceGrapheneGeneral Chemical EngineeringChemistry (all)One-pot synthesisSorptionNanotechnology02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical scienceslaw.inventionchemistry.chemical_compoundchemistrylawQuantum dotChemical Engineering (all)Self-assembly0210 nano-technologyPorous mediumBifunctionalRSC Advances
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Atomically Precise Distorted Nanographenes: The Effect of Different Edge Functionalization on the Photophysical Properties down to the Femtosecond Sc…

2023

Nanographenes (NGs) have been attracting widespread interest since they combine peculiar properties of graphene with molecular features, such as bright visible photoluminescence. However, our understanding of the fundamental properties of NGs is still hampered by the high degree of heterogeneity usually characterizing most of these materials. In this context, NGs obtained by atomically precise synthesis routes represent optimal benchmarks to unambiguously relate their properties to well-defined structures. Here we investigate in deep detail the optical response of three curved hexa-peri-hexabenzocoronene (HBC) derivatives obtained by atomically precise synthesis routes. They are constituted…

distorted hexa-peri-hexabenzocoronene derivativesoptical propertiesatomically precise nanographenesfluorescent nanomaterialsOptical propertiesSettore FIS/01 - Fisica SperimentaleAtomically precise nanographenesGeneral Materials Scienceatomically precise nanographenes; fluorescent nanomaterials; distorted hexa-<i>peri</i>-hexabenzocoronene derivatives; optical propertiesFluorescent nanomaterialsDistorted hexa-perihexabenzocoronene derivativesMaterials
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Fluorescent Boron Oxide Nanodisks as Biocompatible Multi-messenger Sensors for Ultrasensitive Ni$^{2+}$ Detection

2023

Boron-based nanocomposites are very promising for a wide range of technological applications, spanning from microelectronics to nanomedicine. A large variety of B-based nanomaterials has been already observed, such as borospherene, B nanotubes and nanoparticles, and boron nitride nanoparticles. However, their fabrication usually involves toxic precursors or leads to very low yields or small boron atom concentration. In this work, we report the synthesis of nanometric B$_{2}$O$_{3}$ nanodisks, a family of nanomaterials with a quasi-2D morphology capable of intense fluorescence in the visible range. Such as boron-based nanomaterial, which we synthesized by pulsed laser ablation of a boron tar…

boron oxide boron nanocomposites nanosensors nickel detection multi-messenger sensorSettore FIS/01 - Fisica Sperimentaleddc:500NATURAL sciences & mathematics
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Disclosing the emissive surface traps in green-emitting carbon nanodots

2021

Abstract The bright photoluminescence of surface-functionalized carbon nanoparticles, known as carbon nanodots (CDs), has been studied for more than a decade because of its fundamental photo-physical interest and strong technological potential. However, the essential nature of the electronic states involved in their typical light emission remains very elusive. Here, we provide conclusive evidence that surface carboxylic moieties are the key to CD fluorescence. The synergy of nanosecond and femtosecond optical studies, cryogenic fluorescence, computational investigations and chemical engineering of a strategically chosen model CD system, allows to demonstrate that their visible-light transit…

Surface (mathematics)PhotoluminescenceMaterials scienceCryogenic studieschemistry.chemical_element02 engineering and technologyGeneral ChemistryNanosecond010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesFluorescenceFluorescence0104 chemical sciencesElectron transferchemistryChemical physicsFemtosecondFemtosecond spectroscopyCarbon dotsGeneral Materials ScienceLight emissionQuantum chemical calculations0210 nano-technologyCarbon
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Tailoring the Emission Color of Carbon Dots through Nitrogen-Induced Changes of Their Crystalline Structure

2018

Nitrogen content in carbon dots (CDs) plays a crucial role both on the structure and on the optical properties. We synthesized two distinct families of CDs which differ both in structure and in optical emission, demonstrating how nitrogen determines the structure and the optical properties of N-CDs in two main cases: low content and high content of nitrogen. While the low-nitrogen-content family is characterized by blue-emitting nanoparticles with a N-doped hexagonal C-graphite crystalline core structure and a complex surface structure, the high-nitrogen-content family is composed of nanoparticles behaving as dual emitters (blue and green) with a hexagonal β-C3N4crystalline core structure a…

Materials scienceElectronic Optical and Magnetic Materialchemistry.chemical_element02 engineering and technologyCrystal structure010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesNitrogen0104 chemical sciencesElectronic Optical and Magnetic MaterialsSurfaces Coatings and FilmsGeneral EnergyEnergy (all)chemistryChemical engineeringPhysical and Theoretical Chemistry0210 nano-technologyCarbon
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Electron transfer between carbon dots and tetranuclear Dawson-derived sandwich polyanions

2022

Among the photocatalysts which could be used for converting solar energy, polyoxometalates are often regarded as ideal candidates because of their remarkable performances in photocatalytic water splitting and photodegradation of pollutants. Nonetheless, these polyanions are only capable of absorbing UV light, unless coupled to a visible-light photosensitizer. Carbon nanodots are especially promising for this purpose because of their strong visible-light absorption, photostability, non-toxicity, and very low production costs. In this work we demonstrate the possibility of coupling carbon dots to polyoxometalates with different structures, by a simple self-assembly approach based on electrost…

Electron transferLightSettore FIS/01 - Fisica SperimentaleGeneral Physics and AstronomyElectronspolyoxometalatesPhysical and Theoretical ChemistryPolyelectrolytesCarbon DotCarbon nanodotCarbonCatalysisPhysical Chemistry Chemical Physics
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Synthesis of multi-color luminescent ZnO nanoparticles by ultra-short pulsed laser ablation

2020

Abstract Crystalline ZnO nanoparticles (NPs) are synthesized by ultra-short femtosecond (fs) pulsed laser ablation (PLA) of a zinc plate in deionized water, and are investigated by optical absorption and time resolved luminescence spectra in combination with the morphology and structure analysis. The comparison with previous experiments based on short nanosecond (ns) PLA highlights that pulse duration is a crucial parameter to determine the size and the optical properties of ZnO NPs. While short PLA generates NPs with average size S ‾ of ~ 30 nm, ultrashort PLA allows to achieve much smaller NPs, S ‾ ⩽ 10  nm, that evidence weak quantum confinement effects on both the absorption edge and th…

Materials sciencePhotoluminescenceUltrashort pulsed laser ablationZnO nanoparticlesExcitonGeneral Physics and Astronomy02 engineering and technology010402 general chemistry01 natural sciencesAtomic force microscopyAbsorption (electromagnetic radiation)Time resolved luminescencebusiness.industryQuantum confinement effectsSurfaces and InterfacesGeneral ChemistryNanosecond021001 nanoscience & nanotechnologyCondensed Matter Physics0104 chemical sciencesSurfaces Coatings and FilmsAbsorption edgeQuantum dotFemtosecondOptoelectronics0210 nano-technologyLuminescencebusinessTransmission electron microscopyApplied Surface Science
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Photo-Activated Phosphorescence of Ultrafine ZnS:Mn Quantum Dots: On the Lattice Strain Contribution

2021

We address the enhancement of orange-light luminescence of Mn-doped zinc sulfide nanoparticles (NPs) induced by exposure to UV light. Ultrafine ZnS:Mn NPs are prepared by microwave-assisted crystal growth in ethanol, without adding any dispersant agents. When exposed to UV light, their orange emission intensity undergoes a strong increase. This effect is observed when the NPs are deposited as a thin layer on a transparent substrate or dispersed in an ethanolic suspension. Such a feature was already observed on polymer- or surfactant-coated ZnS:Mn NPs and explained as a passivation effect. In this study, by coupling X-ray photoelectron, Fourier transform infrared, and electron paramagnetic r…

General EnergyPhosphorescenceZnS quantum dotsSettore FIS/01 - Fisica SperimentalePoint defectsPhysical and Theoretical ChemistrySurfaces Coatings and FilmsElectronic Optical and Magnetic Materials
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Fluorescent Carbon Nanodots as Sensors of Toxic Metal Ions and Pesticides

2021

Carbon nanodots (CDs) are a new class of fluorescent carbon-based nanomaterials characterized by a plethora of morphologies and sizes. Among these, we can include two different types of CDs, namely, graphitic and diamond-like. This wide range of structures opens up the possibility to design different CDs, with tunable optical properties accordingly to the synthesis method and precursors used. We prepared two different CDs following a bottom-up approach by thermally induced decomposition of organic precursors (namely, citric acid and urea in different molar ratios), and using purification by Size Exclusion Chromatography (SEC). Obtained CDs were characterized by Raman, absorption and fluores…

Materials scienceQuenching (fluorescence)Metal ions in aqueous solutionSize-exclusion chromatographychemistry.chemical_elementFluorescenceNanomaterialssymbols.namesakechemistryChemical engineeringsymbolsAbsorption (chemistry)Raman spectroscopyCarbonThe 8th International Symposium on Sensor Science
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Photocycle of Excitons in Nitrogen-Rich Carbon Nanodots: Implications for Photocatalysis and Photovoltaics

2020

Nitrogen-rich carbon nanodots have emerged as promising nanomaterials for a wide range of applications where a highly emissive and photoactive material with low toxicity and cost-effectiveness is required. One of their hallmarks is indeed a bright, tunable fluorescence of excitonic nature. Disentangling the origin of their optical absorption and fluorescence properties and uncovering relaxation channels and interactions with solvents are some of the most debated issues in the field. Uncovering these aspects is essential for targeted applications, especially in the fields of photocatalysis but also photovoltaics and optoelectronics. Here, we present dedicated transient absorption measurement…

Materials sciencecarbon nanodots carbon nitride surface exciton core exciton photocycle ultrafast spectroscopy exciton emission530 Physicsbusiness.industryExcitonNanotechnologyNanomaterialschemistry.chemical_compoundchemistryPhotovoltaics540 ChemistryUltrafast laser spectroscopyPhotocatalysisGeneral Materials ScienceNanodotbusinessAbsorption (electromagnetic radiation)Carbon nitrideACS Applied Nano Materials
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Disentangling size effects and spectral inhomogeneity in carbon nanodots by ultrafast dynamical hole-burning.

2018

Carbon nanodots (CDs) are a novel family of nanomaterials exhibiting unique optical properties. In particular, their bright and tunable fluorescence redefines the paradigm of carbon as a "black" material and is considered very appealing for many applications. While the field keeps growing, understanding CDs fundamental properties and relating them to their variable structures becomes more and more critical. Two crucial problems concern the effect of size on the electronic structure of CDs, and to what extent their optical properties are influenced by structural disorder. Furthermore, it remains largely unclear whether traditional concepts borrowed from the photo-physics of semiconductor qua…

Potential wellMaterials scienceField (physics)530 Physicschemistry.chemical_element02 engineering and technologyElectronic structure010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter::Mesoscopic Systems and Quantum Hall Effect620 Engineeringcarbon nanodots fluorescent nanomaterials pump probe carbon materials01 natural sciences0104 chemical sciencesNanomaterialsCondensed Matter::Materials SciencechemistryChemical physicsAtomic electron transitionFemtosecond540 ChemistryGeneral Materials Science0210 nano-technologyCarbonUltrashort pulseNanoscale
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Highly Efficient Electron Transfer in a Carbon Dot–Polyoxometalate Nanohybrid

2020

Using solar radiation to fuel catalytic processes is often regarded as the solution to our energy needs. However, developing effective photocatalysts that are active under visible light has proven to be difficult, often due to the toxicity, instability, and high cost of suitable catalysts. We engineered a novel photoactive nanomaterial obtained by the spontaneous electrostatic coupling of carbon nanodots with [P2W18O62]6-, a molecular catalyst belonging to the class of polyoxometalates. While the former are used as photosensitizers, the latter was chosen for its ability to catalyze reductive reactions such as dye decomposition and water splitting. We find the electron transfer within the na…

Carbon dotMaterials sciencecarbon dots photocatalysis ultrafastSettore FIS/01 - Fisica Sperimentale02 engineering and technologyRadiation010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciences7. Clean energy0104 chemical sciencesCatalysisElectron transferPolyoxometalateGeneral Materials SciencePhysical and Theoretical Chemistry0210 nano-technologyVisible spectrumThe Journal of Physical Chemistry Letters
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Characteristic Excitation Wavelength Dependence of Fluorescence Emissions in Carbon "quantum" Dots

2017

Carbon "quantum" dots (CDots), generally defined as small carbon nanoparticles with various surface passivation schemes, have emerged to represent a rapidly advancing and expanding research field. CDots are known for their bright and colorful fluorescence emissions, where the colorfulness is associated with the emissions being excitation wavelength dependent. In this work, CDots with 2,2′-(ethylenedioxy)bis(ethylamine) (EDA) for surface functionalization were studied systematically by using steady-state and time-resolved fluorescence methods. The observed fluorescence quantum yields are strongly excitation wavelength dependent, and the dependence apparently tracks closely the observed absor…

PassivationField (physics)Carbon Nanoparticleschemistry.chemical_element02 engineering and technology010402 general chemistry01 natural sciencesPhysical and Theoretical ChemistryQuantumExcitation wavelengthbusiness.industryElectronic Optical and Magnetic MaterialSettore FIS/01 - Fisica Sperimentale021001 nanoscience & nanotechnologyFluorescence0104 chemical sciencesElectronic Optical and Magnetic MaterialsSurfaces Coatings and FilmsGeneral EnergyEnergy (all)chemistryCarbon quantum dotsOptoelectronicsAtomic physics0210 nano-technologybusinessCarbon
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Carbon Nanodots: A Review—From the Current Understanding of the Fundamental Photophysics to the Full Control of the Optical Response

2018

Carbon dots (CDs) are an emerging family of nanosystems displaying a range of fascinating properties. Broadly speaking, they can be described as small, surface-functionalized carbonaceous nanoparticles characterized by an intense and tunable fluorescence, a marked sensitivity to the environment and a range of interesting photochemical properties. CDs are currently the subject of very intense research, motivated by their possible applications in many fields, including bioimaging, solar energy harvesting, nanosensing, light-emitting devices and photocatalyis. This review covers the latest advancements in the field of CDs, with a focus on the fundamental understanding of their key photophysica…

PhotoluminescenceMaterials science530 PhysicsultrafastphotophysicNanoparticleNanotechnology02 engineering and technology010402 general chemistry01 natural sciencesElectronic stateslcsh:QD241-441lcsh:Organic chemistryCarbon nanodotscarbon dots540 Chemistryfemtosecondcarbon dotphotophysicsphotochemistrynanocarbonSettore FIS/01 - Fisica SperimentaleGeneral Medicine021001 nanoscience & nanotechnology0104 chemical sciencesSolar energy harvestingFemtosecondfluorescence0210 nano-technologyUltrashort pulse
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Transient absorption with a femtosecond tunable excitation pump reveals the emission kinetics of color centers in amorphous silica.

2021

We report a set of femtosecond (fs) transient absorption (TA) measurements following the dynamics of the so-called nonbridging oxygen hole center in silica, a model color center in wide bandgap amorphous solids, characterized by a very large Stokes shift between the UV excitation and its associated red emission at 1.9 eV. The changes in the TA spectrum were probed in the UV-visible range at various delays after photoexcitation and analyzed as a function of the UV excitation energy, in single-photon absorption conditions. The combination of the experiments helps to clarify the defect photocycle, highlighting how TA measurements with tunable UV excitation could represent a powerful tool to in…

Materials scienceAbsorption spectroscopytransient absorption02 engineering and technology01 natural sciencesMolecular physics010309 opticssymbols.namesakeOpticsStokes shift0103 physical sciencesUltrafast laser spectroscopyluminescenceAbsorption (electromagnetic radiation)ultra-fast laser spectroscopyComputingMilieux_MISCELLANEOUS[PHYS.PHYS]Physics [physics]/Physics [physics]business.industrypoint defect021001 nanoscience & nanotechnologyAtomic and Molecular Physics and OpticsAmorphous solidPhotoexcitationsilicaFemtosecondsymbols0210 nano-technologybusinessExcitationOptics letters
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Temperature-Dependence of Solvent-Induced Stokes Shift and Fluorescence Tunability in Carbon Nanodots

2019

We carried out a cryogenic investigation on the optical properties of carbon dots, aiming to better understand their emission mechanism and the role of the solvent. The solvatochromic Stokes shift is quantified by a low temperature approach which allows freezing of the photo-excited state of carbon dots, preventing any solvation relaxation. Moreover, the reduction in temperature helps to identify the dynamical inhomogeneous contribution to the broadening of the emission band; therefore, disentangling the role of solvent from other types of broadening, such as the homogeneous and the static inhomogeneous contributions.

Materials sciencefluorescence tunabilitychemistry.chemical_element02 engineering and technology010402 general chemistry01 natural scienceslcsh:QD241-441symbols.namesakelcsh:Organic chemistrycarbon nanodotCarbon nanodotsStokes shiftcarbon nanodotsSettore FIS/01 - Fisica SperimentaleRelaxation (NMR)SolvatochromismSolvationGeneral Medicine021001 nanoscience & nanotechnologycryogenic optical studyFluorescence0104 chemical sciencesSolventchemistryChemical physicssymbols0210 nano-technologyCarbonC
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The interaction of photoexcited carbon nanodots with metal ions disclosed down to the femtosecond scale

2017

Fluorescent carbon nanodots are a novel family of carbon-based nanoscale materials endowed with an outstanding combination of properties that make them very appealing for applications in nanosensing, photonics, solar energy harvesting and photocatalysis. One of the remarkable properties of carbon dots is their strong sensitivity to the local environment, especially to metal ions in solution. These interactions provide a testing ground for their marked photochemical properties, highlighted by many studies, and frequently driven by charge transfer events. Here we combine several optical techniques, down to femtosecond time resolution, to understand the interplay between carbon nanodots and aq…

Materials scienceQuenching (fluorescence)530 Physicschemistry.chemical_elementNanotechnology02 engineering and technology620 Engineering010402 general chemistry021001 nanoscience & nanotechnologyElementary charge01 natural sciences0104 chemical sciencesIonElectron transferchemistryChemical physicsFemtosecondPhotocatalysisGeneral Materials ScienceMaterials Science (all)0210 nano-technologyGround stateCarbonNanoscale
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Heptagon-Containing Nanographene Embedded into [10]Cycloparaphenylene

2023

We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C60 and C70, with remarkably large binding constants (ca. 107 M−1), as estimated by fluorescence measurements. Nanosecond and femtosecond spectroscopic analysis show that these host-guest complexes are capable of quasi-instantaneous charge separation upon photoexcitation, due to the ultrafast charge transfer from the macrocycle to the complexed fullerene. These r…

NanographenesTransient Absorption SpectroscopySettore FIS/01 - Fisica SperimentaleGeneral MedicineGeneral ChemistryCycloparaphenylenesHost-Guest SystemsMacrocyclesCatalysis
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Sensing of Transition Metals by Top-Down Carbon Dots

2021

Carbon quantum dots (CQDs) are a new class of carbon-rich materials with a range of unique optical and structural properties. They can be defined as carbon nanoparticles, with sizes in the range of 1–10 nm, displaying absorption and emission activities in the UV-VIS range. Depending on the structure, CQDs display a wide variability of properties, which provides the possibility of finely tuning them for several applications. The great advantages of CQDs are certainly the ease of synthesis, non-toxicity, and the strong interactions with the surrounding environment. Based on this, CQDs are especially promising as selective chemosensors. The present study reports on carbon quantum dots synthesi…

TechnologyMaterials scienceAbsorption spectroscopyQH301-705.5Metal ions in aqueous solutionQC1-999chemistry.chemical_elementPhotochemistryIonTransition metalcarbon dotsGeneral Materials ScienceBiology (General)Absorption (electromagnetic radiation)InstrumentationQD1-999sensingFluid Flow and Transfer ProcessesProcess Chemistry and TechnologyTPhysicsGeneral EngineeringEngineering (General). Civil engineering (General)FluorescenceComputer Science ApplicationsChemistrychemistrySurface modificationfluorescenceTA1-2040CarbonApplied Sciences
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Core‐Selective Silver‐Doping of Gold Nanoclusters by Surface‐Bound Sulphates on Colloidal Templates: From Synthetic Mechanism to Relaxation Dynamics

2022

Funding Information: This work was carried out under the ERC Advanced grant (DRIVEN, ERC‐2016‐AdG‐742829), Academy of Finland's Centre of Excellence in Life‐Inspired Hybrid Materials (LIBER, 346108), Academy of Finland (No. 321443, 328942, 308647, and 318891) and Photonic Research and Innovation (PREIN) as well as FinnCERES flagships. L.F. and X.C. thanks for support from CSC (IT Center for Science, Finland) for providing computation resources. The authors acknowledge the provision of facilities and technical support by Aalto University OtaNano – Nanomicroscopy Center (Aalto‐NMC). | openaire: EC/H2020/742829/EU//DRIVEN Ultra-small luminescent gold nanoclusters (AuNCs) have gained substantia…

216 Materials engineeringSettore FIS/01 - Fisica Sperimentaletoxicityphotoluminescencedopinggold nanoclusterscellulose nanocrystalsAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsAdvanced Optical Materials
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Ultrafast spectroscopic investigation on fluorescent carbon nanodots: the role of passivation.

2019

Disentangling the respective roles of the surface and core structures in the photocycle of carbon nanodots is a critical open problem in carbon nanoscience. While the need of passivating carbon dot surfaces to obtain efficiently emitting nanoparticles is very well-known in the literature, it is unclear if passivation introduces entirely new surface emitting states, or if it stabilizes existing states making them fluorescent. In this multi-technique femtosecond spectroscopy study, the relaxation dynamics of non-luminescent (non-passivated) carbon dots are directly compared with their luminescent (passivated) counterparts. Non-passivated dots are found to host emissive states, albeit very sho…

Materials sciencePassivation530 PhysicsGeneral Physics and AstronomyNanoparticlechemistry.chemical_element02 engineering and technology010402 general chemistry01 natural sciences540 ChemistryPhysical and Theoretical ChemistrySurface statesbusiness.industry620 Engineering021001 nanoscience & nanotechnologyFluorescence0104 chemical scienceschemistryAtomic electron transitioncarbon dots ultrafast femtosecondOptoelectronics0210 nano-technologybusinessLuminescenceCarbonFemtochemistryPhysical chemistry chemical physics : PCCP
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Nanosystem for diagnosis and photothermal treatment of tumors

2022

The invention relates to a nanosystem for the diagnosis, image-guided treatment of tumors and monitoring of the tumor microenvironment. The nanosystem is a contrast agent comprising a polymer shell based on a hyaluronic acid nanogel, super-parameg-netic iron oxide nanoparticles (SPIONs) and carbon nanoparticles (CDs).

theranostics nanomedicine MRI photo thermal therapy SPIONs hyaluronic acid
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Ultrafast Interface Charge Separation in Carbon Nanodot-Nanotube Hybrids

2021

Carbon dots are an emerging family of zero-dimensional nanocarbons behaving as tunable light harvesters and photoactivated charge donors. Coupling them to carbon nanotubes, which are well-known electron acceptors with excellent charge transport capabilities, is very promising for several applications. Here, we first devised a route to achieve the stable electrostatic binding of carbon dots to multi- or single-walled carbon nanotubes, as confirmed by several experimental observations. The photoluminescence of carbon dots is strongly quenched when they contact either semiconductive or conductive nanotubes, indicating a strong electronic coupling to both. Theoretical simulations predict a favo…

pump probe spectroscopyNanotubeMaterials scienceCarbon nanotubeschemistry.chemical_elementCarbon nanotubeCarbon nanodotsPhotoinduced electron transferlaw.inventionCondensed Matter::Materials ScienceElectron transferlawUltrafast laser spectroscopyGeneral Materials Sciencecarbon nanodotsNATURAL sciences & mathematicsCarbon nanohybridschemistry.chemical_classificationcarbon nanotubesbusiness.industryElectron acceptorCondensed Matter::Mesoscopic Systems and Quantum Hall EffectPump probe spectroscopyUltrafast electron transferultrafast electron transferchemistrycarbon nanohybridsOptoelectronicsddc:500NanodotbusinessCarbonResearch Article
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Gold Au(I)6 Clusters with Ligand-Derived Atomic Steric Locking: Multifunctional Optoelectrical Properties and Quantum Coherence

2023

Funding Information: This work was supported by the ERC Advanced grant (DRIVEN, ERC‐2016‐AdG‐742829), the ERC grant (834742), the EU H2020‐MSCA‐RISE‐872049 (IPN‐Bio), the Academy of Finland's Centre of Excellence in Molecular Engineering of Biosynthetic Hybrid Materials Research (HYBER, 2014–2019), and Life‐Inspired Hybrid Materials (LIBER, 346108), Academy of Finland project fundings (No. 352900, 314810, 333982, 336144, 352780, 352930 and 353364), FinnCERES and Photonics Research and Innovation (PREIN) flagship programs. The authors acknowledge the provision of facilities and technical support by Aalto University OtaNano – Nanomicroscopy Center (Aalto‐NMC). | openaire: EC/H2020/834742/EU//…

third-harmonic generationquantum coherenceSettore FIS/01 - Fisica Sperimentalenanoclustersfield effect transistorsphotoluminescenceAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic Materials
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Effect of Halogen Ions on the Photocycle of Fluorescent Carbon Nanodots

2019

Carbon dots (C-dots) are well-known for their strong sensitivity to the environment, which reflects on intensity and shape changes of their fluorescence, induced by various interacting ions and molecules in solution. Although these interactions have been extensively studied in the last few years, especially in view of their possible sensing applications, the existing works have mostly focused on the quenching of C-dot fluorescence induced by metal cations. In fact, these latter easily bind to C-dots surfaces, which are negatively charged in most cases, promoting an electron transfer from the surface to them. Much less is known from the literature on the effect induced on C-dots by prototypi…

Photoluminescencequenchingfluorescence quenching02 engineering and technology010402 general chemistryPhotochemistryultrafast transient absorption01 natural sciencesIonlcsh:QD241-441lcsh:Organic chemistrycarbon nanodotheavy atom effectPhysics::Atomic and Molecular ClustersMoleculecarbon nanodotsQuenching (fluorescence)ChemistrySettore FIS/01 - Fisica SperimentaleGeneral Medicine021001 nanoscience & nanotechnologyFluorescence0104 chemical sciencesIntersystem crossingHalogenAbsorption (chemistry)0210 nano-technologyC
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Different natures of surface electronic transitions of carbon nanoparticles

2017

The photoluminescence behaviour of carbon-based nanodots is still debated. Both core and surface structures are involved in the emission mechanism, and the electronic transitions can be modified by external agents such as metal ions or pH, but the general relation between the structure and the optical function is poorly understood. Here, we report a comparative study on the effects of these variables, changing the core structure from crystalline to amorphous, and modifying the surface structure by different passivation procedures. Our results highlight that the emission mechanism of the tunable visible fluorescence is identical for crystalline and amorphous samples, indicating the independe…

PhotoluminescencePassivationGeneral Physics and Astronomychemistry.chemical_elementNanotechnology02 engineering and technologyChromophore010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesAmorphous solidPhysics and Astronomy (all)chemistryChemical physicsAtomic electron transitionSurface modificationNanodotPhysical and Theoretical Chemistry0210 nano-technologyCarbon
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Photoinduced charge transfer from Carbon Dots to Graphene in solid composite

2019

Abstract The emission in solid phase of Carbon Dots (CDs) deposited by drop-casting technique is investigated by means of micro-photoluminescence. Graphene and SiO2 are used as substrates, and the influence of their different nature – conductive or insulating – on the emission of CDs is highlighed. In particular, a systematic loss of efficiency in the emission of CDs on graphene is found, suggesting a CD-graphene interaction possibly due to a photoinduced electron transfer between the surface states of CDs and the conduction band of graphene. Finally, thanks to the negligible influence on CDs emission, SiO2 substrate is used as support to perform thermal processing of CDs in solid phase, sh…

Materials scienceComposite numberThermal processingchemistry.chemical_element02 engineering and technologySubstrate (electronics)01 natural sciencesPhotoinduced electron transferlaw.inventionCharge transfergraphene carbon dotslawPhase (matter)0103 physical sciencesThermalMaterials ChemistryCarbon dotsPhotoluminescenceSurface states010302 applied physicsbusiness.industryGrapheneMetals and AlloysSurfaces and Interfaces021001 nanoscience & nanotechnologySurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialschemistryOptoelectronicsGraphene0210 nano-technologybusinessCarbon
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Engineered Ferritin with Eu3+ as a Bright Nanovector: A Photoluminescence Study

2022

Ferritin nanoparticles play many important roles in theranostic and bioengineering applications and have been successfully used as nanovectors for the targeted delivery of drugs due to their ability to specifically bind the transferrin receptor (TfR1, or CD71). They can be either genetically or chemically modified for encapsulating therapeutics or probes in their inner cavity. Here, we analyzed a new engineered ferritin nanoparticle, made of the H chain mouse ferritin (HFt) fused with a specific lanthanide binding tag (LBT). The HFt-LBT has one high affinity lanthanide binding site per each of the 24 subunits and a tryptophane residue within the tag that acts as an antenna able to transfer …

engineered ferritin photoluminescence europium nanovectorGeneral MedicinePhysical and Theoretical ChemistryBiochemistry
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Carbon Dots Dispersed on Graphene/SiO2/Si: A Morphological Study

2019

Low-dimensional carbon materials occupy a relevant role in the field of nanotechnology. Herein, the authors report a study conducted by atomic force microscopy and Raman spectroscopy on the deposition of carbon dots onto graphene surfaces. The study aims at understanding if and how the morphology and the microstructure of chemical vapor deposited graphene on Si/SiO2 may change due to the interaction with the carbon dots. Potential alteration in the graphene's electrical properties might be detrimental for optoelectronic applications. The deposition of carbon dots dispersed in water and ethanol solvents are explored to investigate the effect of solvents with different fluidic properties. The…

atomic force microscopyMaterials scienceGrapheneAtomic force microscopychemistry.chemical_elementSurfaces and InterfacesCondensed Matter PhysicsSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialslaw.inventionGraphene carbon dotssymbols.namesakechemistryChemical engineeringlawchemical vapor deposited graphenecarbon dotsRaman spectroscopyMaterials ChemistrysymbolsElectrical and Electronic EngineeringRaman spectroscopyCarbon
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Solvatochromism Unravels the Emission Mechanism of Carbon Nanodots

2016

High quantum yield, photoluminescence tunability, and sensitivity to the environment are hallmarks that make carbon nanodots interesting for fundamental research and applications. Yet, the underlying electronic transitions behind their bright photoluminescence are strongly debated. Despite carbon-dot interactions with their environment should provide valuable insight into the emitting transitions, they have hardly been studied. Here, we investigate these interactions in a wide range of solvents to elucidate the nature of the electronic transitions. We find remarkable and systematic dependence of the emission energy and kinetics on the characteristics of the solvent, with strong response of …

Range (particle radiation)PhotoluminescenceChemistrySettore FIS/01 - Fisica SperimentaleSolvatochromismQuantum yield02 engineering and technologyElectron010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistryCondensed Matter::Mesoscopic Systems and Quantum Hall Effect01 natural sciencesFluorescence0104 chemical sciencesCondensed Matter::Materials ScienceChemical physicsAtomic electron transitionGeneral Materials ScienceSpontaneous emissionCarbon dots photoluminescence nanomaterialsPhysical and Theoretical Chemistry0210 nano-technologyThe Journal of Physical Chemistry Letters
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Dynamic modification of Fermi energy in single-layer graphene by photoinduced electron transfer from carbon dots

2020

Graphene (Gr)&mdash

Materials scienceGeneral Chemical Engineeringchemistry.chemical_element2D materialPhotoinduced electron transferArticleNanomaterialslaw.inventionlcsh:Chemistrysymbols.namesakelawGeneral Materials ScienceSurface statesGraphenecarbonFermi energymaterial sciencePhotoexcitationlcsh:QD1-999chemistryChemical physicsRaman spectroscopysymbolsnanomaterialGrapheneRaman spectroscopyCarbon
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A Comparative Study of Top-Down and Bottom-Up Carbon Nanodots and Their Interaction with Mercury Ions

2021

We report a study of carbon dots produced via bottom-up and top-down routes, carried out through a multi-technique approach based on steady-state fluorescence and absorption, time-resolved fluorescence spectroscopy, Raman spectroscopy, infrared spectroscopy, and atomic force microscopy. Our study focuses on a side-to-side comparison of the fundamental structural and optical properties of the two families of fluorescent nanoparticles, and on their interaction pathways with mercury ions, which we use as a probe of surface emissive chromophores. Comparison between the two families of carbon dots, and between carbon dots subjected to different functionalization procedures, readily identifies a …

Materials scienceoptical nanomaterialsGeneral Chemical Engineeringchemistry.chemical_elementInfrared spectroscopyChromophorePhotochemistryFluorescenceArticleFluorescence spectroscopyChemistrysymbols.namesakechemistrycarbon dotssymbolsSurface modificationGeneral Materials ScienceRaman spectroscopyAbsorption (electromagnetic radiation)QD1-999CarbonsensingNanomaterials
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UV photobleaching of carbon nanodots investigated by in situ optical methods.

2020

Carbon dots are a family of optically-active nanoparticles displaying a combination of useful properties that make them attractive for many applications in photonics and photochemistry. Despite the initial claims of high photostability of carbon dots even under prolonged illuminations, several recent studies have evidenced their photobleaching (PB) under UV light, detrimental for some applications. A study of the mechanism and dynamics of carbon dot PB can be considered a useful route to gather relevant information on the underlying photophysics of these nanoparticles, which is still widely debated. Here we report a study of the PB of carbon dots under UV light, conducted through optical ex…

Materials sciencebusiness.industrySettore FIS/01 - Fisica SperimentaleGeneral Physics and Astronomychemistry.chemical_elementNanoparticle02 engineering and technologyChromophore010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesPhotobleachingFluorescence0104 chemical scienceschemistryIrradiationPhysical and Theoretical ChemistryPhotonicsCarbon dots photobleaching fluorescence0210 nano-technologybusinessAbsorption (electromagnetic radiation)CarbonPhysical chemistry chemical physics : PCCP
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β-C3N4 Nanocrystals: Carbon Dots with Extraordinary Morphological, Structural, and Optical Homogeneity

2018

Carbon nanodots are known for their appealing optical properties, especially their intense fluorescence tunable in the visible range. However, they are often affected by considerable issues of optical and structural heterogeneity, which limit their optical performance and limit the practical possibility of applying these nanoparticles in several fields. Here we developed a synthesis method capable of producing a unique variety of carbon nanodots displaying an extremely high visible absorption strength (ε &gt; 3 × 106 M(dot)−1 cm−1) and a high fluorescence quantum yield (73%). The high homogeneity of these dots reflects in many domains: morphological (narrow size distribution), structural (q…

Materials sciencebusiness.industryGeneral Chemical EngineeringSettore FIS/01 - Fisica SperimentaleNanoparticleQuantum yield02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyLaser01 natural sciencesFluorescenceMolecular electronic transition0104 chemical scienceslaw.inventionNanocrystallawOptical cavityHomogeneity (physics)Materials Chemistrycarbon nanodots fluorescent nanopraticlesOptoelectronics0210 nano-technologybusinessChemistry of Materials
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Simultaneous photonic and excitonic coupling in spherical quantum dot supercrystals

2020

Semiconductor nanocrystals, or quantum dots (QDs), simultaneously benefit from inexpensive low-temperature solution processing and exciting photophysics, making them the ideal candidates for next-generation solar cells and photodetectors. While the working principles of these devices rely on light absorption, QDs intrinsically belong to the Rayleigh regime and display optical behavior limited to electric dipole resonances, resulting in low absorption efficiencies. Increasing the absorption efficiency of QDs, together with their electronic and excitonic coupling to enhance charge carrier mobility, is therefore of critical importance to enable practical applications. Here, we demonstrate a ge…

Materials scienceGeneral Physics and AstronomyPhotodetectortransient absorptionPhysics::OpticsSupraparticlesquantum dots02 engineering and technology010402 general chemistry01 natural sciencesArticlesymbols.namesakeCondensed Matter::Materials SciencenanocrystalsMie theoryGeneral Materials ScienceRayleigh scatteringAbsorption (electromagnetic radiation)BiexcitonTransient absorptionsupercrystalsbusiness.industryCondensed Matter::OtherQuantum dotsSupercrystalsGeneral EngineeringMetamaterialself-assemblySelf-assembly021001 nanoscience & nanotechnologyCondensed Matter::Mesoscopic Systems and Quantum Hall Effect0104 chemical sciencesNanocrystalsNanocrystalsupraparticlesQuantum dotddc:540symbolsOptoelectronicsPhotonics0210 nano-technologybusinessPhysical Chemistry and Soft Matter
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Decagram-Scale Synthesis of Multicolor Carbon Nanodots: Self-Tracking Nanoheaters with Inherent and Selective Anticancer Properties

2022

Carbon nanodots (CDs) are a new class of carbon-based nanoparticles endowed with photoluminescence, high specific surface area, and good photothermal conversion, which have spearheaded many breakthroughs in medicine, especially in drug delivery and cancer theranostics. However, the tight control of their structural, optical, and biological properties and the synthesis scale-up have been very difficult so far. Here, we report for the first time an efficient protocol for the one-step synthesis of decagram-scale quantities of N,S-doped CDs with a narrow size distribution, along with a single nanostructure multicolor emission, high near-infrared (NIR) photothermal conversion efficiency, and sel…

theranosticsMolecular StructureCell SurvivalInfrared RaysOptical ImagingAntineoplastic AgentsBiocompatible Materialstargeted cancer therapyCarbonCell Linemulticolor emissionMaterials TestingHumansNanoparticlesGeneral Materials Sciencecarbon nanodotshigh yield synthesisDrug Screening Assays AntitumorReactive Oxygen SpeciesCell Proliferation
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Fluorescent nitrogen-rich carbon nanodots with an unexpected β-C3N4nanocrystalline structure

2016

Carbon nanodots are a class of nanoparticles with variable structures and compositions which exhibit a range of useful optical and photochemical properties. Since nitrogen doping is commonly used to enhance the fluorescence properties of carbon nanodots, understanding how nitrogen affects their structure, electronic properties and fluorescence mechanism is important to fully unravel their potential. Here we use a multi-technique approach to study heavily nitrogen-doped carbon dots synthesized by a simple bottom-up approach and capable of bright and color-tunable fluorescence in the visible region. These experiments reveal a new variant of optically active carbonaceous dots, that is a nanocr…

Materials scienceBand gapSettore FIS/01 - Fisica Sperimentalenanocarbon photoluminescence photo-physics photo-chemistryNanoparticlechemistry.chemical_elementNanotechnology02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesFluorescenceSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)Nanocrystalline material0104 chemical scienceschemistryNanocrystalMaterials ChemistryBeta carbon nitride0210 nano-technologyCarbonSurface statesJournal of Materials Chemistry C
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Highly Homogeneous Biotinylated Carbon Nanodots: Red-Emitting Nanoheaters as Theranostic Agents toward Precision Cancer Medicine

2019

Very recent red-emissive carbon nanodots (CDs) have shown potential as near-infrared converting tools to produce local heat useful in cancer theranostics. Besides, CDs seem very appealing for clinical applications combining hyperthermia, imaging, and drug delivery in a single platform capable of selectively targeting cancer cells. However, CDs still suffer from dramatic dot-to-dot variability issues such that a rational design of their structural, optical, and chemical characteristics for medical applications has been impossible so far. Herein, we report for the first time a simple and highly controllable layer-by-layer synthesis of biotin-decorated CDs with monodisperse size distribution, …

Fluorescence-lifetime imaging microscopyphotothermal therapyMaterials scienceCell SurvivalAntineoplastic AgentsNanotechnology02 engineering and technology010402 general chemistrytargeted cancer therapy01 natural sciencesDrug Delivery Systemsbiotincarbon nanodotCell Line TumorCarbon nanodotsHumansGeneral Materials SciencePrecision MedicineRational designimagingPhotothermal therapy021001 nanoscience & nanotechnologyCarbonNanostructures0104 chemical sciencesbiotin; carbon nanodots; imaging; photothermal therapy; targeted cancer therapy.Settore CHIM/09 - Farmaceutico Tecnologico ApplicativoBiotinylationDrug deliveryCancer cellMCF-7 CellsSurface modification0210 nano-technologyACS Applied Materials &amp; Interfaces
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Pressure-Dependent Tuning of Photoluminescence and Size Distribution of Carbon Nanodots for Theranostic Anticancer Applications

2020

Carbon nanodots (CDs) have recently attracted attention in the field of nanomedicine because of the biocompatibility, cost-effective nature, high specific surface, good near infrared (NIR) photothermal conversion into heat and tunable fluorescence properties, which have paved the way toward incorporating use of CDs into innovative anticancer theranostic platforms. However, a reliable synthesis of CDs with established and controlled physiochemical proprieties is precluded owing to the lack of full manipulation of thermodynamic parameters during the synthesis, thus limiting their use in real world medical applications. Herein, we developed a robust solvothermal protocol which allow fine contr…

theranosticsMaterials sciencePhotoluminescenceBiocompatibilityMDA-MB-231Nanotechnology02 engineering and technologySurface engineering010402 general chemistrylcsh:Technology01 natural sciencesArticleFluorescence spectroscopyAdsorptionGeneral Materials Sciencecarbon nanodotsFourier transform infrared spectroscopylcsh:Microscopylcsh:QC120-168.85lcsh:QH201-278.5lcsh:T021001 nanoscience & nanotechnology0104 chemical scienceslcsh:TA1-2040cancer therapyNanomedicineSurface modificationlcsh:Descriptive and experimental mechanicslcsh:Electrical engineering. Electronics. Nuclear engineeringlcsh:Engineering (General). Civil engineering (General)0210 nano-technologylcsh:TK1-9971phototherapyMaterials
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Printable Thermo- and Photo-stable Poly(D,L-lactide)/Carbon Nanodots Nanocomposites via Heterophase Melt-Extrusion Transesterification

2022

We propose for the first time an one-pot synthesis of carbon nanodots-poly(D,L-lactide) (CDs-PLA) nanocomposites, obtained by a simple reactive melt-extrusion process involving polar surface groups of multicolor CDs and ester bonds of PLA chains. Apart from providing an excellent method to produce polyester-coated CDs, our protocol allows obtaining perfect PLA@CDs blends giving rise to homogeneous extruded PLA@CDs filaments (ePLA@CDs) suitable for 3D printing applications (e.g., additive manufacturing for biomaterials and biodegradable encoded polymer ink technology). We demonstrate that ePLA@CDs filaments can be used to build a huge range of fluorescent objects with increasing architectura…

Settore CHIM/09 - Farmaceutico Tecnologico ApplicativoGeneral Chemical EngineeringSettore FIS/01 - Fisica SperimentaleEnvironmental Chemistrycarbon dots polymer nanocompositesGeneral ChemistryIndustrial and Manufacturing EngineeringChemical Engineering Journal
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CCDC 2237075: Experimental Crystal Structure Determination

2023

Related Article: Juan P. Mora-Fuentes, Marcos D. Codesal, Marco Reale, Carlos M. Cruz, Vicente G. Jiménez, Alice Sciortino, Marco Cannas, Fabrizio Messina, Victor Blanco, Araceli G. Campaña|2023|Angew.Chem.,Int.Ed.|62||doi:10.1002/anie.202301356

Space GroupCrystallographyCrystal Systemcyclo-145:7414:1121:2431:3441:4451:5461:6471-septiphenyl-(811-di-t-butyl-19H-benzo[5'6']tetraceno[1'12'11'10':56789]tetrapheno[1011121-nopqab]pleiaden-19-one) unknown solvateCrystal StructureCell ParametersExperimental 3D Coordinates
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