This work was sponsored by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy, grant no. DE-FG02-12ER16352. S.T.H. thanks the National Science Foundation for financial support through the National Science Foundation Graduate Research Fellowship under Grant No. 1122374.

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The authors have nothing to disclose.

ويرد الإجراء لتوليف غير متكلس والمعادن إنهاء كربيد المعادن الانتقالية ونيتريد النانوية مع أحجام الانضباطي وهيكل هنا تشمل 26 خطوات حاسمة في الأسلوب: استخدام RBF خالية من الرطوبة لاحتواء المخفف السلائف آلكوكسيد المعدنية، وتجنب الفلزات القلوية الشوائب خلال جميع ?...

كربيد المعدنية الانتقال المبكر (TMCs) هي منخفضة التكلفة، ومواد الأرض الوفيرة التي تظهر الاستقرار الحراري والكهروكيميائية عالية فضلا عن الأنشطة المحفزة فريدة من نوعها. 1-3 وعلى وجه الخصوص، كربيد التنغستن (WC) وكربيد الموليبدينوم (مو 2 C) لديها تمت دراستها على نطاق واسع لأوجه التشابه الحفازة لمعادن مجموعة البلاتين (PGMs). 4،5 نظرا لهذه الخصائص مواتية، وقد تم تحديد TMCs كمرشحين لاستبدال المواد الحفازة PGM مكلفة في تكنولوجيات الطاقة المتجددة، مثل تحويل الكتلة الحيوية وخلايا الوقود الناشئة، والكهربي. 6،7 لتحقيق أقصى قدر من النشاط التحفيزي، تصاغ المحفزات التجارية دائما تقريبا كما النانوية الصغر (أقطار &lt;10 نانومتر) مبددة على دعم مساحة عالية، مثل الكربون الأسود. 8 ومع ذلك، فإن تركيب TMCs يتطلب درجات حرارة أعلى من ~ 700 درجة مئوية. وهذا يؤدي إلى تلبد واسعة من nanoparticليه (NPS)، ترسب الكربون الزائد السطحية (الكوك)، وتدهور دعم الحراري. كلا تلبد الجسيمات وتدهور الدعم يؤدي إلى تناقص المساحات السطحية المادية. الزائدة الشوائب السطحية كتل ترسب مواقع المعادن النشطة، وهو ما ثبت للحد بشكل كبير أو في بعض الحالات تقضي تماما على النشاط التحفيزي من TMCs. 9،10 وعلى هذا النحو، يتم إجراء الدراسة الأساسية للTMC التفاعل في الغالب على المجهرية الدقيقة السائبة أو الأغشية الرقيقة مع التحكم بدقة الأسطح بدلا من التركيز على مساحة عالية متناهية الصغر TMC. وقد تم تطوير العديد من الطرق لتجميع TMC مصادر القدرة النووية، ولكن هذه الأساليب ليست مناسبة لتوليف ناشطة تحفيزيا مصادر القدرة النووية TMC. تقنيات التشريب الرطب التقليدية تستخدم محاليل ملحية معدنية مشربة على دعم مساحة عالية. على التدفئة، يمكن أن طرق التلقيح الرطب يعرض دعم المحفز لظروف الكربنة المدمرة الرائدة لدعم تدهور. وعلاوة على ذلك، تلبد جويمكن التخفيف فقط في انخفاض شحنات٪ بالوزن من المعدن على الدعم، وليس من الممكن أيضا أن تجميع مساحيق النانو TMC غير معتمد باستخدام التشريب الرطب. العديد من الطرق الجديدة تنطوي على خلط تمهيدا المعادن مع مقدمة الكربون وتطبيق تقنيات التدفئة التقليدية وغير التقليدية، ويستخدم 11-18 الكربون الزائد لمنع التكلس، ولكن هذه النتائج الكربون الزائدة في الكربون سطح واسع، مما يجعل هذه المواد غير مناسبة للتطبيقات الحفازة. ونظرا لهذه التحديات الاصطناعية، تقليديا درس TMCs كما شارك المحفزات 11 لPGMs، ويدعم حافزا لPGMs، 19-22 أو يدعم لالطبقات الوحيدة PGM النشطة 23-25 ​​الطريقة المعروضة هنا يوفر القدرة على تجميع كلا غير متكلس- ومنتهية المعادن TMC مصادر القدرة النووية وكذلك نيتريد المعادن الانتقالية (TMN) مصادر القدرة النووية مع أحجام الانضباطي، مراحل البلورية، والتركيب المعدني. 26 تقديم الأسلوب يوفر أيضا أبility للحصول على TMC أو TMN nanodispersions أو إيداع TMC وTMN مصادر القدرة النووية على منطقة الدعم حافزا سطح ارتفاع في درجة حرارة الغرفة، وبالتالي التخفيف من تدهور دعم الحراري. هذه الطريقة بالتالي فهي مناسبة للتطبيقات الحفازة مستقل من TMC وTMN مصادر القدرة النووية، وتطوير متقدمة multimetallic TMC وTMN مصادر القدرة النووية، أو غيرها من التطبيقات التي تتطلب أحجام الجسيمات التي تسيطر عليها بدقة والأسطح. 26 الطريقة المعروضة هنا يستخدم بروتوكول ثلاث خطوات لتجميع TMC وTMN مصادر القدرة النووية. في الخطوة الأولى، يتم استخدام microemulsion العكسي (RME) لأكسيد معطف أوائل المعادن الانتقالية (TMO) المصادر في nanospheres السيليكا. يتم تحضير مستحلب عن طريق تشتيت قطرات الماء في وسط اقطبي باستخدام السطحي غير أيوني التجاري. ثم يتعرض مصادر القدرة النووية TMO مغلفة السيليكا إما الكربنة أو المعالجة الحرارية nitridizing. هنا، والسيليكا يمنع الجسيمات تلبد في درجات حرارة عالية بينما يسمح للغازات رد الفعل أن ينتشر إلى Tانه TMO مصادر القدرة النووية وتحويلها إلى TMC أو TMN مصادر القدرة النووية. وفي الخطوة الأخيرة، تتم إزالة القذائف السيليكا باستخدام العلاج الحمضية أو القلوية للحصول على TMC أو TMN nanodispersions التي يمكن أن تكون مشتتة على دعم مساحة عالية، مثل الكربون الأسود.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>n-heptane</td>
			<td>Sigma-Aldrich</td>
			<td>246654</td>
			<td></td>
		</tr>
		<tr>
			<td>polyoxyethylene (4) lauryl ether</td>
			<td>Sigma-Aldrich</td>
			<td>235989</td>
			<td>Brij&#174; L4</td>
		</tr>
		<tr>
			<td>tungsten (VI) isopropoxide</td>
			<td>Alfa Aesar</td>
			<td>40247</td>
			<td>W(VI)IPO</td>
		</tr>
		<tr>
			<td>tungsten (VI) chloride</td>
			<td>Sigma-Aldrich</td>
			<td><a href="http://www.sigmaaldrich.com/catalog/product/aldrich/241911?lang=en&amp;region=US">241911</a></td>
			<td>To prepare W(VI)IPO, homemade</td>
		</tr>
		<tr>
			<td>tungsten (IV) chloride</td>
			<td>Strem Chemicals</td>
			<td>74-2348</td>
			<td>To prepare W(IV)IPO, homemade</td>
		</tr>
		<tr>
			<td>tantalum (V) isopropoxide</td>
			<td>Alfa Aesar</td>
			<td><a href="http://www.alfa.com/en/catalog/40038">40038</a></td>
			<td>Ta(V)IPO</td>
		</tr>
		<tr>
			<td>niobium (V) isopropoxide</td>
			<td>Alfa Aesar</td>
			<td><a href="http://www.alfa.com/en/catalog/36572">36572</a></td>
			<td>Nb(V)IPO</td>
		</tr>
		<tr>
			<td>nickel (II) methoxyethoxide</td>
			<td>Alfa Aesar</td>
			<td>42377</td>
			<td>Ni(II)MEO</td>
		</tr>
		<tr>
			<td>titanium (IV) isopropoxide</td>
			<td>Sigma-Aldrich</td>
			<td><a href="http://www.sigmaaldrich.com/catalog/product/aldrich/87560?lang=en&amp;region=US">87560</a></td>
			<td>Ti(IV)IPO</td>
		</tr>
		<tr>
			<td>molybdenum (V) isopropoxide</td>
			<td>Alfa Aesar</td>
			<td><a href="http://www.alfa.com/en/catalog/39159">39159</a></td>
			<td>Mo(V)IPO</td>
		</tr>
		<tr>
			<td>molybdenum (V) chloride</td>
			<td>Sigma-Aldrich</td>
			<td><a href="http://www.sigmaaldrich.com/catalog/product/aldrich/208353?lang=en&amp;region=US">208353</a></td>
			<td>To prepare Mo(V)IPO, homemade</td>
		</tr>
		<tr>
			<td>tetraethyl orthosilicate</td>
			<td>Sigma-Aldrich</td>
			<td>333859</td>
			<td>TEOS</td>
		</tr>
		<tr>
			<td>ammonium hydroxide</td>
			<td>Sigma-Aldrich</td>
			<td>320145</td>
			<td></td>
		</tr>
		<tr>
			<td>methanol</td>
			<td>Sigma-Aldrich</td>
			<td>34860</td>
			<td></td>
		</tr>
		<tr>
			<td>anhydrous isopropanol</td>
			<td>Sigma-Aldrich</td>
			<td><a href="http://www.sigmaaldrich.com/catalog/product/sial/278475?lang=en&amp;region=US">278475</a></td>
			<td>To prepare homemade alkoxides</td>
		</tr>
		<tr>
			<td>ammonium bifluoride</td>
			<td>Sigma-Aldrich</td>
			<td>224820</td>
			<td></td>
		</tr>
		<tr>
			<td>carbon black</td>
			<td>Cabot Corp.</td>
			<td>Vulcan&#174; XC72R</td>
			<td></td>
		</tr>
		<tr>
			<td>Methane</td>
			<td>AirGas</td>
			<td>ME R300</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen</td>
			<td>AirGas</td>
			<td>HY UHP300</td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonia</td>
			<td>AirGas</td>
			<td>AM AH80N705</td>
			<td></td>
		</tr>
		<tr>
			<td>Quartz Tube Furnace</td>
			<td>MTI Corp.</td>
			<td>OTF-1200X-S-UL</td>
			<td></td>
		</tr>
	</tbody>
</table>

reverse microemulsion-mediated synthesis of monometallic and bimetallic early transition metal carbide and nitride nanoparticles

ويستخدم microemulsion العكسي لتغليف جزيئات أكسيد أوائل الفلزات الإنتقالية الواحد من المعدن أو متعلق بنظام المعدنين في قذائف السيليكا الصغيرة التي. ثم يتم carburized النانوية أكسيد المعادن مغلفة السيليكا في جو الميثان / الهيدروجين في درجات حرارة أكثر من 800 درجة مئوية لتشكيل الانتقال المبكر النانوية كربيد معدنية مغلفة السيليكا. أثناء عملية كربنة، وقذائف السيليكا تمنع تلبد النانوية كربيد المجاورة في حين منع أيضا ترسب الكربون سطح الزائد. بدلا من ذلك، النانوية أكسيد المعادن مغلفة السيليكا يمكن nitridized في جو الأمونيا في درجات حرارة أكثر من 800 درجة مئوية لتشكيل الانتقال المبكر النانوية نيتريد معدنية مغلفة السيليكا. عن طريق ضبط المعلمات عكس microemulsion، سمك قذائف السيليكا، والظروف كربنة / نتردة، وكربيد أو نيتريد النانوية المعدنية الانتقالية يمكن ضبطها لمختلف الأحجام، والتراكيب، ومراحل الكريستال الثانية. بعد كربنة أو نتردة، ثم يتم إزالة القذائف السيليكا باستخدام إما درجة حرارة الغرفة مائي حل ثنائي فلوريد الأمونيوم أو 0،1-0،5 M محلول هيدروكسيد الصوديوم في 40-60 درجة مئوية. في حين أن قذائف السيليكا وتذيبها، ودعم ارتفاع المساحة السطحية، مثل أسود الكربون، ويمكن أن يضاف إلى هذه الحلول للحصول على دعم المرحلة الانتقالية في وقت مبكر كربيد المعدنية أو نيتريد النانوية. وإذا أضيف أي دعم مساحة عالية، ومن ثم يمكن تخزين النانوية باعتباره nanodispersion أو طرد للحصول على nanopowder.

في الخطوة الأولى من البروتوكول، والهدف من ذلك هو تغليف الواحد من المعدن أو متعلق بنظام المعدنين أكسيد المعادن الانتقالية (TMO) مصادر القدرة النووية في نطاق السيليكا الصغيرة التي الشكل 1 يوضح الصور التي التقطت من التوليفات تمثيلية قبل وبعد هطول الأمطار مع الم?...

Watch this Scientific Journal Video about Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles at JoVE.com

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

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.

عكس التجميعي بوساطة Microemulsion من الواحد من المعدن ومتعلق بنظام المعدنين في وقت مبكر الانتقال المعادن كربيد ونتريد النانوية

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

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Chemistry

10.7K Views.  Massachusetts Institute of Technology. A “removable ceramic coating method” 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.

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

Anticancer Metal Complexes: Synthesis and Cytotoxicity Evaluation by the MTT Assay

Titanium (IV) and vanadium (V) complexes are highly potent anticancer agents. A challenge in their synthesis refers to their hydrolytic instability; therefore their preparation should be conducted under an inert atmosphere. Evaluation of the anticancer activity of these complexes can be achieved by the MTT assay.
The MTT assay is a colorimetric viability assay based on enzymatic reduction of the MTT molecule to formazan when it is exposed to viable cells. The outcome of the reduction is a color change of the MTT molecule. Absorbance measurements relative to a control determine the percentage of remaining viable cancer cells following their treatment with varying concentrations of a tested compound, which is translated to the compound anticancer activity and its IC50 values. The MTT assay is widely common in cytotoxicity studies due to its accuracy, rapidity, and relative simplicity.
Herein we present a detailed protocol for the synthesis of air sensitive metal based drugs and cell viability measurements, including preparation of the cell plates, incubation of the compounds with the cells, viability measurements using the MTT assay, and determination of IC50 values.

A method for synthesis of air-sensitive titanium and vanadium anticancer agents is described, along with the evaluation of their cytotoxic activity towards human cancer cell line by the MTT Assay.

المضادة للسرطان المعادن مجمعات: التجميعي والتقييم السمسة قبل الفحص الإنتقالي العسكري

Titanium (IV) and vanadium (V) complexes are highly potent anticancer agents. A challenge in their synthesis refers to their hydrolytic instability; ...

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

أطر توليف وتوصيف بين functionalized المعدنية العضوية

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups and scaffolds. Traditional methods for the preparation of ynones are associated with drawbacks including harsh conditions, multiple purification steps, and the presence of unwanted byproducts. An alternative method for the straightforward preparation of ynones from acyl chlorides and potassium alkynyltrifluoroborate salts is described herein. The adoption of organotrifluoroborate salts as an alternative to organometallic reagents for the formation of new carbon-carbon bonds has a number of advantages. Potassium organotrifluoroborate salts are shelf stable, have good functional group tolerance, low toxicity, and a wide variety are straightforward to prepare. The title reaction proceeds rapidly at ambient temperature in the presence of a Lewis acid without the exclusion of air and moisture. Fair to excellent yields may be obtained via reaction of various aryl and alkyl acid chlorides with alkynyltrifluoroborate salts in the presence of boron trichloride.

The goal of this manuscript is to demonstrate a straightforward method for the preparation of ynones from acyl chloride and potassium alkynyltrifluoroborate salt starting materials. The one-pot reaction proceeds rapidly in the presence of boron trichloride without exclusion of air and moisture.

خالية من المعادن توليف Ynones من أصيل الكلوريدات والبوتاسيوم Alkynyltrifluoroborate أملاح

Ynones are a valuable functional group and building block in organic synthesis. Ynones serve as a precursor to many important organic functional groups ...

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.

التوليف، وتوصيف، وFunctionalization الهجين الاتحاد الافريقي / أقراص مدمجة والاتحاد الافريقي / ZnS الأساسية / شل النانوية

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

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

This protocol presents both the synthesis method of the Ni single atom catalyst, and the electrochemical testing of its catalytic activity and selectivity in aqueous CO2 reduction. Different from traditional metal nanocrystals, the synthesis of metal single atoms involves a matrix material that can confine those single atoms and prevent them from aggregation. We report an electrospinning and thermal annealing method to prepare Ni single atoms dispersed and coordinated in a graphene shell, as active centers for CO2 reduction to CO. During the synthesis, N dopants play a critical role in generating graphene vacancies to trap Ni atoms. Aberration-corrected scanning transmission electron microscopy and three-dimensional atom probe tomography were employed to identify the single Ni atomic sites in graphene vacancies. Detailed setup of electrochemical CO2 reduction apparatus coupled with an on-line gas chromatography is also demonstrated. Compared to metallic Ni, Ni single atom catalyst exhibit dramatically improved CO2 reduction and suppressed H2 evolution side reaction.

Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction

Here, we present a protocol for the synthesis and electrochemical testing of transition metal single atoms coordinated in graphene vacancies as active centers for selective carbon dioxide reduction to carbon monoxide in aqueous solutions.

التوليف والأوصاف الأداء من المعادن الانتقالية ذرة واحدة محفز للحد من2 CO الكهروكيميائية

This protocol presents both the synthesis method of the Ni single atom catalyst, and the electrochemical testing of its catalytic activity and selectivity ...

Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles

The size, size distribution and stability of colloidal nanoparticles are greatly affected by the presence of capping ligands. Despite the key contribution of capping ligands during the synthesis reaction, their role in regulating the nucleation and growth rates of colloidal nanoparticles is not well understood. In this work, we demonstrate a mechanistic investigation of the role of trioctylphosphine (TOP) in Pd nanoparticles in different solvents (toluene and pyridine) using in situ SAXS and ligand-based kinetic modeling. Our results under different synthetic conditions reveal the overlap of nucleation and growth of Pd nanoparticles during the reaction, which contradicts the LaMer-type nucleation and growth model. The model accounts for the kinetics of Pd-TOP binding for both, the precursor and the particle surface, which is essential to capture the size evolution as well as the concentration of particles in situ. In addition, we illustrate the predictive power of our ligand-based model through designing the synthetic conditions to obtain nanoparticles with desired sizes. The proposed methodology can be applied to other synthesis systems and therefore serves as an effective strategy for predictive synthesis of colloidal nanoparticles.

The main goal of this work is to elucidate the role of capping agents in regulating the size of palladium nanoparticles by combining in situ small angle x-ray scattering (SAXS) and ligand-based kinetic modeling.

يجند بوساطة التنو ونمو البلاديوم معدنية جسيمات نانوية

The size, size distribution and stability of colloidal nanoparticles are greatly affected by the presence of capping ligands. Despite the key contribution ...

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.

توليف لنظام المعدنين جسيمات نانوية Pt/Sn-تعتمد في السوائل الأيونية

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

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. Here, we introduce the molten-salt synthesis (MSS) method for making metal oxide nanomaterials. Advantages over other methods include its simplicity, greenness, reliability, scalability, and generalizability. Using pyrochlore lanthanum hafnium oxide (La2Hf2O7) as a representative, we describe the MSS protocol for the successful synthesis of complex metal oxide nanoparticles (NPs). Furthermore, this method has the unique ability to produce NPs with different material features by changing various synthesis parameters such as pH, temperature, duration, and post-annealing. By fine-tuning these parameters, we are able to synthesize highly uniform, non-agglomerated, and highly crystalline NPs. As a specific example, we vary the particle size of the La2Hf2O7&#160;NPs by changing the concentration of the ammonium hydroxide solution used in the MSS process, which allows us to further explore the effect of particle size on various properties. It is expected that the MSS method will become a more popular synthesis method for nanomaterials and more widely employed in the nanoscience and nanotechnology community in the upcoming years.

Here, we demonstrate a unique, relatively low-temperature, molten-salt synthesis method for preparing uniform complex metal oxide lanthanum hafnate nanoparticles.

الملح المنصهر توليف أكسيد المعدن معقدة جسيمات نانوية

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

تركيب وتوصيف جسيمات نانوية الذهب أمفيفيليك

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal catalysis, the literature on direct heteroarylation is scarce. The presence of heteroatoms such as nitrogen, sulfur and oxygen often make heteroarylation a challenging research field due to catalyst poisoning, product decomposition and the rest. This protocol details a highly efficient direct &#945;-C(sp3) heteroarylation of ketones under microwave irradiation. Key factors for successful heteroarylation include the use of XPhos Palladacycle Gen. 4 Catalyst, excess base to suppress side reactions and the high temperature and pressure achieved in a sealed reaction vial under microwave irradiation. The heteroarylation compounds prepared by this method were fully characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance spectroscopy (13C NMR) and high-resolution mass spectrometry (HRMS). This methodology has several advantages over literature precedents including broad substrate scope, rapid reaction time, greener procedure and operational simplicity by eliminating the preparation of intermediates such as silyl enol ether. Possible applications for this protocol include, but are not limited to, diversity-oriented synthesis for the discovery of biologically active small molecules, domino synthesis for the preparation of natural products and ligand development for new transition metal catalytic systems.

Heteroaryl compounds are important molecules utilized in organic synthesis, medicinal and biological chemistry. A microwave-assisted heteroarylation using palladium catalysis provides a rapid and efficient method to attach heteroaryl moieties directly to ketone substrates.

الهيتزرريليشن المباشر بمساعدة الميكروويف من الكيتونات باستخدام الحفز المعدني الانتقالي

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal ...