Dr. B.P.S. Chauhan would like to gratefully acknowledge William Paterson University for assigned release time (ART) award for part of the research described here and also for the research program in general.

Nota: Tutti i reagenti sono utilizzati come è dal produttore, senza ulteriore purificazione. Le reazioni sono state monitorate per fino ad una settimana tramite spettroscopia UV-Vis per assicurare riduzione completa. Tutte le reazioni sono svolte sotto una cappa di sfiato e abbigliamento adeguato la sicurezza è sempre usati, compresi i guanti, occhiali di protezione, e camici. 1. Sintesi di argento nanoparticelle <ol><li> Pesare 0.0169 g (0,1 mmoli) di nitrato d&#39;argento direttamente in un pallone da 50 ml Erlenmeyer. </li><li> Aggiungere a 20 ml di 18,2 MW di acqua ultrapura e un bar agitatore magnetico. Coprire pallone con tappo per evitare l&#39;evaporazione. </li><li> Inserire pallone in un bagno d&#39;olio situato su una piastra agitatore / calda e garantire che la temperatura viene mantenuta a 60 ° C. </li><li> Aggiungere lentamente 144 ml (0,2 mmoli) di 2-AST utilizzando una micropipetta di precisione. Lavare pipetta più volte in soluzione per garantire che tutti silano viene trasferito nella soluzione. </li><li> Prendere le letture spettroscopia UV-Vissecondo il protocollo di cui alla sezione 5. </li><li> Dopo 6 ore, rimuovere il campione dal bagno d&#39;olio e versare in un flacone da 20 ml di esempio per l&#39;archiviazione, TEM, FTIR e ulteriori analisi. Nota: Sintesi di nanoparticelle di oro e palladio segue il metodo e stechiometrici stessi importi ad eccezione di nanoparticelle di oro richiedono 216 ml (0,3 mmol) 2-AST. La reazione può continuare a produrre nanoparticelle per un massimo di 2 settimane, ma il tasso non è significativo rispetto al tasso iniziale. </li></ol> 2. Microscopio Elettronico a Trasmissione (TEM) Preparazione del campione <ol><li> Assicurarsi che campione è raffreddato a RT. </li><li> Posizionare una griglia di rame formvar rivestite 200 carbonio-maglia su un pezzo di carta pulito filtro. </li><li> Utilizzando un 1 ml di plastica pipetta Pasteur, cast-goccia circa 60 ml di campione nanoparticelle direttamente sulla griglia. </li><li> Lasciare griglia per asciugare per 24 ore prima di imaging. </li><li> Prendere immagini TEM ad alta risoluzione con le seguenti condizioni:Attuali 10 μA e 100 kV tensione di accelerazione 22. </li></ol> 3. Risonanza Magnetica Nucleare (NMR) Preparazione del campione Nota: Eseguire NMR a temperatura ambiente. Ad alte temperature segnali possono fondersi, che degrada la qualità degli spettri ottenuti. <ol><li> Usando una pipetta di precisione, pipetta 50 ml di anidride deuterio (D 2 O) in una provetta pulita NMR. </li><li> Con un&#39;altra pipetta di precisione pulita, pipetta 400 ml di campione nanoparticelle nella stessa tubo NMR. <ol><li> Come campioni possono aderire alle pareti interne del tubo NMR, aggiungere lentamente soluzioni nel tubo NMR. Se il campione non aderisce, tappare la provetta e agitare la parte superiore del tubo per forzare la soluzione al fondo. </li></ol></li><li> Mescolare il campione agitando e ripetutamente invertendo il tubo NMR. </li><li> Luogo provetta nel NMR seguendo le indicazioni stabilite dal protocollo NMR fornito dal produttore. Un verso l&#39;alto di 1.000 scansioni possono essere necessari per res corretteoluzione in un programma di impulso protonica NMR 1 H. Nota: pareti del tubo NMR devono essere pulite. Si raccomanda che la parete esterna del tubo viene pulito con una microfibra o un panno privo di lanugine prima dell&#39;analisi per chiarezza spettri. </li><li> Scartare campione al termine. Non restituire campione di soluzione madre. </li></ol> 4. trasformata di Fourier (FTIR) Spettroscopia di preparazione del campione <ol><li> Mettere 2 ml di campione nanoparticelle in un piccolo contenitore di vetro. Una fiala di vetro 3 ml di tubo o 1 dram funziona bene. </li><li> Essiccare i campioni collocando il contenitore di vetro in un essiccatore a vuoto provvista di rubinetto. </li><li> Fissare essiccatore agli apparecchi pompa a vuoto. L&#39;essiccazione dei campioni può richiedere alcune ore a seconda della forza del vuoto. Considerare i campioni asciutto dopo non c&#39;è liquido visibile nel contenitore. </li><li> Raschi giù il campione con una spatola pulita e raccogliere materiali solidi. </li><li> Posizionare il materiale solido sul ATR-FTIR spettroscopia dotato di cris ZnSeal laser a diodi. </li><li> Ottenere spettri FTIR integrando 32 scansioni tra 4,000-500 cm -1 con una risoluzione spettrale di 2,0. Utilizzare l&#39;aria background 23. </li></ol> 5. UV-Vis Spectroscopy Preparazione del campione <ol><li> Effettuare spettroscopia UV-Vis su campioni di nanoparticelle che sono in un 9:59 diluizione del campione di nanoparticelle di acqua in modo che la saturazione non si verifica in analisi spettrometro. </li><li> Rimuovere i campioni di nanoparticelle per UV-Vis mentre la reazione è in funzione a intervalli di mezz&#39;ora. </li><li> Usando una pipetta di precisione, togliere 100 ml di materiale di nanoparticelle e posto in una provetta di plastica. </li><li> Aggiungere 1 ml di acqua ultrapura per la stessa cuvetta e mescolare accuratamente svuotando la pipetta più volte. </li><li> Record UV-Vis spettro di assorbimento 250-800 nm. </li><li> Dopo l&#39;analisi, non tornare campione reazione. Smaltire analita in modo appropriato. </li></ol>

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Sali riportati in questo documento sono gli unici sali che sono stati testati di questo metallo. Come risultato, non è certo che questa strategia reazione sarebbe lavorare con tutti i sali dei metalli, in particolare l&#39;oro. La solubilità di questi sali in acqua può anche influenzare l&#39;esito della reazione in termini di tempo di reazione, la morfologia, e le rese. In tutte le reazioni, il silano è stato aggiunto ad una soluzione di sale di metallo già disciolto. Vale la pena nota...

Poiché la domanda e le applicazioni di aumenti progettista nanomateriali, in modo da fare i vari metodi di sintesi. I metodi &quot;top-down&quot;, quali l&#39;ablazione laser o attacco chimico sono stati impiegati per la loro eccellente controllabilità e capacità di risolvere materiali attendibile al livello sub-micron. Questi metodi si basano su materiali sfusi in lavorazione in componenti più sottili, che tipicamente aumentano il costo di produzione come la dimensione desiderata nanostruttura diminuisce. Un metodo alternativo di sintesi a questo è l&#39;approccio &quot;bottom-up&quot;, che controlla la sintesi a livello molecolare e si accumula alla nanostruttura desiderata. Ciò conferisce un notevole grado di controllo sulla desiderata autoassemblaggio, funzionalità, passività e stabilità nella generazione di questi materiali nanostrutturati 1. Lavorando dal livello molecolare, nanocompositi ibridi possono essere generati fornire i vantaggi di entrambi i materiali della stessa structuri. Come nanomateriali sono sintetizzati attraverso la strategia bottom-up, metodi devono essere utilizzati per controllare la dimensione delle particelle, forma, struttura, idrofobicità, la porosità, la carica, e la funzionalità 2. In sintesi nanoparticelle nucleo metallico, il sale metallico è sensibilmente ridotto in un processo autocatalitico per generare particelle zero-valente, che a sua volta dirigono la nucleazione di altra particella. Questo porta a clustering e la produzione di nanoparticelle, infine, 3. Nel tentativo di controllare la dimensione delle nanoparticelle create e impedire loro di precipitare dalla soluzione, stabilizzanti come leganti, tensioattivi, carica ionica e grandi polimeri vengono sfruttati per la loro capacità di bloccare le nanoparticelle da ulteriori agglomerato 4-10. Questi materiali inibiscono la van der Waals attrazione delle nanoparticelle, sia attraverso ingombro sterico dovuto alla presenza di gruppi voluminosi e attraverso repulsioni coulombiano 3. in til suo lavoro, una, una pentola, strategia sintetica facile per la generazione delle varie nanoparticelle nucleo metallico utilizzando il silano, N- (2-amminoetil) -3-aminosilanetriol (2-AST) è presentato (Figura 1). Ligandi di questo composto sono in grado di ridurre precursori metallo e stabilizzare nanoparticelle metalliche con un relativamente elevata efficacia. Le tre frazioni silanolici presenti sono anche in grado di reticolazione e questo costituisce una rete interconnessa di polimero silano organico impregnato di nanoparticelle di sua matrice (Figura 2). A differenza di molti silani, che facilmente subiscono idrolisi in presenza di acqua, questo composto è stabilizzato in acqua, che è vantaggioso per scopi idrofobicità, stabilità e controllo.

<table><tbody><tr><td>n-(2-aminoethyl)-3-aminosilanetriol (2-AST)</td><td>Gelest</td><td>SIA0590.0</td><td>25% in H&lt;sub&gt;2&lt;/sub&gt;O</td></tr><tr><td>Silver nitrate</td><td>Sigma Aldrich</td><td>S6506</td><td></td></tr><tr><td>Gold(III) chloride trihydrate</td><td>Sigma Aldrich</td><td>520918</td><td></td></tr><tr><td>Palladium(II) Nitrate</td><td>Alfa Aesar</td><td>11035</td><td></td></tr><tr><td>Deuterium Dioxide</td><td>Cambridge Isotope Laboratories</td><td>DLM-4-100</td><td></td></tr></tbody></table>

generation of zerovalent metal core nanoparticles using n-(2-aminoethyl)-3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.

La reazione è stata monitorata tramite spettrometria UV-Vis come formazione di nanoparticelle dovrebbe produrre picchi caratteristici per ciascuna nanoparticella di metallo individuo. L&#39;analisi finale dei materiali sintetizzati stato realizzato attraverso TEM e FTIR. Gli spettri FTIR stato ottenuto da polvere essiccata di campioni. L&#39;analisi granulometrica può essere ottenuto misurando il diametro delle nanoparticelle da immagini ottenute mediante TEM e risultati delle medie. <...

Watch this Scientific Journal Video about Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol at JoVE.com

Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

Generazione di zerovalente Metal Core nanoparticelle Uso n- (2-amminoetil) -3-aminosilanetriol

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of ...

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Universidad San Sebastian

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Chemistry

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol

7.6K Views.  William Paterson University. A novel method for metal core nanoparticle synthesis using a water stable silanol is described.

Video: Generation of Zerovalent Metal Core Nanoparticles Using n-2-aminoethyl-3-aminosilanetriol

Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

We present a template-free method for &#8220;polymerizing&#8221; nanoparticles into long chains without side branches. A variety of nanoparticles are encapsulated in polystyrene-block-poly(acrylic acid) (PSPAA) shells and then used as monomers for their self-assembly. Spherical PSPAA micelles upon acid treatment are known to assemble into cylindrical micelles. Exploiting this tendency, the core-shell nanoparticles are induced to aggregate, coalesce, and then transform into long chains. When more than one type of nanoparticles are used, random and block &#8220;copolymers&#8221; of nanoparticles can be obtained. Detailed procedures are reported for the PSPAA encapsulation of nanoparticles, homo- and co-polymerization of the core-shell nanoparticles, separation and purification of the resulting nanoparticle chains. Transformations of single-line chains into double- and triple-line chains are also presented. The synergy between the polymer shell and the embedded nanoparticles leads to an unusual chain-growth polymerization mode, giving long nanoparticle chains that are distinct from the products of the traditional step-growth aggregation process.

Using Polystyrene-block-polyacrylic acid-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization

We report protocols for &#8220;polymerizing&#8221; various types of polymer-encapsulated metal nanoparticles into long chains of &#8220;homo-&#8220; and &#8220;co-polymers&#8221;.

Utilizzando Polystyrene-<em&gt; Blocco</em&gt; -poly (Acido acrilico) Rivestiti metallo Nanoparticelle come monomeri per loro omo- e co-polimerizzazione

We present a template-free method for &#8220;polymerizing&#8221; nanoparticles into long chains without side branches. A variety of nanoparticles are ...

Ricerca

Chimica

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

Reverse Sintesi Microemulsione mediata di Monometallic e bimetallico precoce transizione metallo carburo e nitruro di nanoparticelle

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

Sintesi, Caratterizzazione, e funzionalizzazione di ibrida UA / CdS e Au / ZnS core / shell nanoparticelle

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Sintesi e caratterizzazione di supramolecolari colloidi

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

A Rapid Synthesis Method for Au, Pd, and Pt Aerogels Via Direct Solution-Based Reduction

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various precursor noble metal ions with reducing agents in a 1:1 (v/v) ratio results in the formation of metal gels within seconds to minutes compared to much longer synthesis times for other techniques such as sol-gel. Conducting the reduction step in a microcentrifuge tube or small volume conical tube facilitates a proposed nucleation, growth, densification, fusion, equilibration model for gel formation, with final gel geometry smaller than the initial reaction volume. This method takes advantage of the vigorous hydrogen gas evolution as a by-product of the reduction step, and as a consequence of reagent concentrations. The solvent accessible specific surface area is determined with both electrochemical impedance spectroscopy and cyclic voltammetry. After rinsing and freeze drying, the resulting aerogel structure is examined with scanning electron microscopy, X-ray diffractometry, and nitrogen gas adsorption. The synthesis method and characterization techniques result in a close correspondence of aerogel ligament sizes. This synthesis method for noble metal aerogels demonstrates that high specific surface area monoliths may be achieved with a rapid and direct reduction approach.

A rapid, direct solution-based reduction synthesis method to obtain Au, Pd, and Pt aerogels is presented.

Un metodo di sintesi rapida per Au, Pd e Pt Aerogels tramite riduzione diretta basata su soluzione

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various ...

Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular physico-chemical properties of ionic liquids (ILs) are exploited to control both nucleation and growth processes. The nanoparticles form colloidal sols of very high colloidal stability in the IL, which is particularly interesting in view of their use as quasi-homogeneous catalysts. Procedures for both nanoparticle extraction in conventional solvents and for nanoparticle precipitation are presented. The size, structure and composition of the synthesized nanocrystals are confirmed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX). By this, we show that the nanocrystals are random-type alloy and of small (2-3 nm) size. The catalytic activity and selectivity in the hydrogenation of &#945;,&#946;-unsaturated aldehydes is tested in a semi-continuous batch-type reactor. In this context, the bimetallic Pt/Sn-based nanoparticles reveal a high selectivity towards the unsaturated alcohol.

A protocol for the synthesis of bimetallic nanoparticles in ionic liquids and the procedure of their catalytic testing in the selective hydrogenation of unsaturated aldehydes are described.

Sintesi di nanoparticelle bimetalliche Pt/Sn-basato in liquidi ionici

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular ...

Imine Metathesis by Silica-Supported Catalysts Using the Methodology of Surface Organometallic Chemistry

With this protocol, a well-defined singlesite silica-supported heterogeneous catalyst [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is designed and prepared according to the methodology developed by surface organometallic chemistry (SOMC). In this framework, catalytic cycles can be determined by isolating crucial intermediates. All air-sensitive materials are handled under inert atmosphere (using gloveboxes or a Schlenk line) or high vacuum lines (HVLs, &#60;10-5 mbar). The preparation of SiO2-700 (silica dehydroxylated at 700 &#176;C) and subsequent applications (the grafting of complexes and catalytic runs) requires the use of HVLs and double-Schlenk techniques. Several well-known characterization methods are used, such as Fourier-transform infrared spectroscopy (FTIR), elemental microanalysis, solid-state nuclear magnetic resonance spectroscopy (SSNMR), and state-of-the-art dynamic nuclear polarization surface enhanced NMR spectroscopy (DNP-SENS). FTIR and elemental microanalysis permit scientists to establish the grafting and its stoichiometry. 1H and 13C SSNMR allows the structural determination of the hydrocarbon ligands coordination sphere. DNP SENS is an emerging powerful technique in solid characterization for the detection of poorly sensitive nuclei (15N, in our case). SiO2-700 is treated with about one equivalent of the metal precursor compared to the amount of surface silanol (0.30 mmol&#183;g-1) in pentane at room temperature. Then, volatiles are removed, and the powder samples are dried under dynamic high vacuum to afford the desired materials [(&#8801;Si-O-)Hf(&#951;2&#960;-MeNCH2)(&#951;1-NMe2)(&#951;1-HNMe2)]. After a thermal treatment under high vacuum, the grafted complex is converted into metal imido silica complex [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)]. [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] effectively promotes the metathesis of imines, using the combination of two imine substrates, N-(4-phenylbenzylidene)benzylamine, or N-(4-fluorobenzylidene)-4-fluoroaniline, with N-benzylidenetert-butylamine as substrates. A significantly lower conversion is observed with the blank runs; thus, the presence of the imido group in [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is correlated to the catalytic performance.

A new group IV metal catalyst for imine metathesis is prepared by grafting amine metal complex onto dehydroxylated silica. Surface metal fragments are characterized using FT-IR, elemental microanalysis, and solid-state NMR spectroscopy. Further dynamic nuclear polarization surface enhanced NMR spectroscopy experiments complement the determination of the coordination sphere.

Metatesi imine da silice-supported Catalysts Utilizzando la metodologia della chimica dell'organimetallico di superficie

With this protocol, a well-defined singlesite silica-supported heterogeneous catalyst [(&#8801;Si-O-)Hf(=NMe)(&#951;1-NMe2)] is designed and prepared ...

Preparation of Silver-Palladium Alloyed Nanoparticles for Plasmonic Catalysis under Visible-Light Illumination

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles (NPs) can accelerate and control the selectivity of a variety of molecular transformations. This opens possibilities for the use of visible or near-IR light as a sustainable input to drive and control reactions when plasmonic nanoparticles supporting LSPR excitation in these ranges are employed as catalysts. Unfortunately, this is not the case for several catalytic metals such as palladium (Pd). One strategy to overcome this limitation is to employ bimetallic NPs containing plasmonic and catalytic metals. In this case, the LSPR excitation in the plasmonic metal can contribute to accelerate and control transformations driven by the catalytic component. The method reported herein focuses on the synthesis of bimetallic silver-palladium (Ag-Pd) NPs supported on ZrO2 (Ag-Pd/ZrO2) that acts as a plasmonic-catalytic system. The NPs were prepared by co-impregnation of corresponding metal precursors on the ZrO2 support followed by simultaneous reduction leading to the formation of bimetallic NPs directly on the ZrO2 support. The Ag-Pd/ZrO2 NPs were then used as plasmonic catalysts for the reduction of nitrobenzene under 425 nm illumination by LED lamps. Using gas chromatography (GC), the conversion and selectivity of the reduction reaction under the dark and light irradiation conditions can be monitored, demonstrating the enhanced catalytic performance and control over selectivity under LSPR excitation after alloying non-plasmonic Pd with plasmonic metal Ag. This technique can be adapted to a wide range of molecular transformations and NPs compositions, making it useful for the characterization of the plasmonic catalytic activity of different types of catalysis in terms of conversion and selectivity.

Presented here is a protocol for the synthesis of silver-palladium (Ag-Pd) alloy nanoparticles (NPs) supported on ZrO2 (Ag-Pd/ZrO2). This system allows for harvesting energy from visible light irradiation to accelerate and control molecular transformations. This is illustrated by nitrobenzene reduction under light irradiation catalyzed by Ag-Pd/ZrO2 NPs.

Preparazione di nanoparticelle in lega di palladio d'argento per la catalisi plasmonica sotto illuminazione a luce visibile

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles (NPs) can accelerate and control the selectivity of a variety of molecular ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.

Sintesi della nanoparticella d'oro

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of ...

Triplet Fusion Upconversion Nanocapsule Synthesis

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has significant implications for producing high energy light beyond a material's surface. However, the deployment of UC materials has been stymied due to poor material solubility, high concentration requirements, and oxygen sensitivity, ultimately resulting in reduced light output. Toward this end, nanoencapsulation has been a popular motif to circumvent these challenges, but durability has remained elusive in organic solvents. Recently, a nanoencapsulation technique was engineered to tackle each of these challenges, whereupon an oleic acid nanodroplet containing upconversion materials was encapsulated with a silica shell. Ultimately, these nanocapsules (NCs) were durable enough to enable triplet fusion upconversion-facilitated volumetric three-dimensional (3D) printing. By encapsulating upconversion materials with silica and dispersing them in a 3D printing resin, photopatterning beyond the surface of the printing vat was made possible. Here, video protocols for the synthesis of upconversion NCs are presented for both small-scale and large-scale batches. The outlined protocols serve as a starting point for adapting this encapsulation scheme to multiple upconversion schemes for use in volumetric 3D printing applications.

This protocol details the synthesis of upconversion nanocapsules for subsequent use in photopolymerizable resins for triplet fusion upconversion-facilitated volumetric 3D printing.

Tripletta Fusione Upconversion Nanocapsule Sintesi

Triplet fusion upconversion (UC) allows for the generation of one high energy photon from two low energy input photons. This well-studied process has ...