Name: a simple and efficient protocol for the catalytic insertion polymerization of functional norbornenes
Uploaded: 2017-02-27T13:00:00
Description: Watch this Scientific Journal Video about A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes at JoVE.com

The authors acknowledge funding from Fonds de Recherche du Qu&#233;bec - Nature et Technologies, from Conseil Recherches en Sciences Naturelles et G&#233;nie (program INNOV) and PrimaQu&#233;bec.

1. Preparation of Poly(5-norbornene-2-carboxylic acid), PNBE(CO2H)
<ol>
	<li>Preparation of the monomer NBE(CO2H)
	<ol>
		<li>Weigh out acrylic acid (AA) (327 g, 4.5 mol, 2 eq.) and hydroquinone (4.9 g, 4.5 x 10-2 mol, 0.02 eq.) and add them to a 2 L round-bottom flask equipped with a condenser and a magnetic stir bar. Heat the flask at 150 &#176;C using a silicone oil bath.</li>
		<li>Once reflux is settled, add DCPD (300 g, 2.3 mol, 1 eq.) in a single portion, and the...

<ol>
	<li>Gaylord, N. G., Mandal, B. M., Martan, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peroxide-induced+polymerization+of+norbornene.">Peroxide-induced polymerization of norbornene.</a> J. Polym. Science, Polym. Lett. Ed. 14 (9), 555-559 (1976).</li><li>Janiak, C., Lassahn, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+vinyl+homopolymerization+of+norbornene.">The vinyl homopolymerization of norbornene.</a> Macromol. Rapid Comm. 22 (7), 479-493 (2001).</li><li>Bielawski, C. W., Grubbs, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Living+ring-opening+metathesis+polymerization.">Living ring-opening metathesis polymerization.</a> Prog. Polym. Sci. 32 (1), 1-29 (2007).</li><li>Blank, F., Janiak, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metal+catalysts+for+the+vinyl/addition+polymerization+of+norbornene.">Metal catalysts for the vinyl/addition polymerization of norbornene.</a> Coord. Chem. Rev. 253 (7-8), 827-861 (2009).</li><li>Kaminsky, W., Boggioni, L., Tritto, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cycloolefin+polymerization.">Cycloolefin polymerization.</a> Polymer Science: A Comprehensive Reference, 10 Volume Set. 3, 843-873 (2012).</li><li>Boggioni, L., Tritto, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=State+of+the+art+of+cyclic+olefin+polymers.">State of the art of cyclic olefin polymers.</a> MRS Bull. 38 (3), 245-251 (2013).</li><li>Goodall, B., Rieger, B., Baugh, L., Kacker, S., Striegler, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cycloaliphatic+polymers+via+late+transition+metal+catalysis.">Cycloaliphatic polymers via late transition metal catalysis.</a> Late Transition Metal Polymerization Catalysis. , 101-154 (2003).</li><li>Zhou, W., He, X., Chen, Y., Chen, M., Shi, L., Wu, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vinyl-addition+copolymerization+of+norbornene+and+polar+norbornene+derivatives+using+novel+bis(&#946;-ketoamino)Ni(II)/B(C6F5)3/AlEt3+catalytic+systems.">Vinyl-addition copolymerization of norbornene and polar norbornene derivatives using novel bis(&#946;-ketoamino)Ni(II)/B(C6F5)3/AlEt3 catalytic systems.</a> J. Appl. Polym. Sci. 120 (4), 2008-2016 (2011).</li><li>M&#252;ller, K., Jung, Y., Yoon, D. Y., Agarwal, S., Greiner, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vinyl-type+polymerization+of+alkylester-substituted+norbornenes+without+endo/exo+separation.">Vinyl-type polymerization of alkylester-substituted norbornenes without endo/exo separation.</a> Macromol. Chem. Phys. 211 (14), 1595-1601 (2010).</li><li>Boffa, L. S., Novak, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Copolymerization+of+polar+monomers+with+olefins+using+transition-metal+complexes.">Copolymerization of polar monomers with olefins using transition-metal complexes.</a> Chem. Rev. 100 (4), 1479-1494 (2000).</li><li>Funk, J. K., Andes, C. E., Sen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Addition+Polymerization+of+Functionalized+Norbornenes:+The+Effect+of+Size+Stereochemistry,+and+Coordinating+Ability+of+the+Substituent.">Addition Polymerization of Functionalized Norbornenes: The Effect of Size Stereochemistry, and Coordinating Ability of the Substituent.</a> Organometallics. 23 (8), 1680-1683 (2004).</li><li>Hennis, A. D., Polley, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel,+efficient,+palladium-based+system+for+the+polymerization+of+norbornene+derivatives:+Scope+and+mechanism.">Novel, efficient, palladium-based system for the polymerization of norbornene derivatives: Scope and mechanism.</a> Organometallics. 20 (13), 2802-2812 (2001).</li><li>Commarieu, B., Claverie, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bypassing+the+lack+of+reactivity+of+endo-substituted+norbornenes+with+the+catalytic+rectification-insertion+mechanism.">Bypassing the lack of reactivity of endo-substituted norbornenes with the catalytic rectification-insertion mechanism.</a> Chem. Sci. 6 (4), 2172-2182 (2015).</li><li>Commarieu, B., Potier, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrahigh+Tg+epoxy+thermosets+based+on+insertion+polynorbornenes.">Ultrahigh Tg epoxy thermosets based on insertion polynorbornenes.</a> Macromoecules. 49 (3), 920-925 (2016).</li><li>Pirrung, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Synthetic Organic Chemist's Companion. , (2007).</li><li>Kanao, M., Otake, A., Tsuchiya, K., Ogino, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereo-selective+synthesis+of+5-norbornene-2-exo-carboxylic+acid-Rapid+isomerization+and+kinetically+selective+hydrolysis.">Stereo-selective synthesis of 5-norbornene-2-exo-carboxylic acid-Rapid isomerization and kinetically selective hydrolysis.</a> Int. J. Org. Chem. 2 (1), 26-30 (2012).</li><li>Huertas, D., Florscher, M., Dragojlovic, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solvent-free+Diels-Alder+reactions+of+in+situ+generated+cyclopentadiene.">Solvent-free Diels-Alder reactions of in situ generated cyclopentadiene.</a> Green Chem. 11 (1), 91-95 (2009).</li><li>Pierre, F., Commarieu, B., Tavares, A. C., Claverie, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Tg+sulfonated+insertion+polynorbornene+ionomers+prepared+by+catalytic+insertion+polymerization.">High Tg sulfonated insertion polynorbornene ionomers prepared by catalytic insertion polymerization.</a> Polymer. 86, 91-97 (2016).</li><li>Woo, H. G., Li, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Advanced functional materials, Chapter 1.6.8,30. 1, (2011).</li><li>Kim, D. -. G., Bell, A., Register, R. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Living+vinyl+addition+polymerization+of+substituted+norbornenes+by+a+t-Bu3P-Ligated+Methylpalladium+Complex.">Living vinyl addition polymerization of substituted norbornenes by a t-Bu3P-Ligated Methylpalladium Complex.</a> ACS Macro Letters. 4 (3), 327-330 (2015).</li><li>Seung, H., S, A., Baek, K., Sang, S., Intech, S. i. l. a. g. u. i. ,. M. .. A. .. ,. e. d. .. ,. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low+Dielectric+Materials+for+Microelectronics.">Low Dielectric Materials for Microelectronics.</a> Dielectric Material. , 59-76 (2012).</li></ol>

The method proposed here is simple, and readily amenable to scale-up. All chemicals could be used as received without any purification. Note that performing the reaction at a lower scale (e.g. scales &#8804;1 g) usually yields lower yields due to an unavoidable loss of material during the handling and the collection.
The catalysts are formed in situ upon the reaction of commercial Pd compounds with cationizing agents. In our hands, the yield of the reaction as well as the cha...

Norbornene, NBE, the Diels-Alder adduct of ethylene and cyclopentadiene (obtained by &#34;cracking&#34; of dicyclopentadiene (DCPD)), is readily polymerized using either free-radical polymerization,1 cationic polymerization,2 ring-opening metathesis polymerization3 and catalytic insertion polymerization.4,5,6,7 Unlike the other mechanisms, the catalytic insertion polymerization leads to the formation of a very high glass-transition temperature (Tg) polymer whereby the bicyclic backbone of NBE is conserved. A variety of catalysts such as metallocene catalysts and late transition metal catalysts can be used to promote the polymerization of NBE.4,5,6,7 However, due to its low solubility and due to difficulties associated with the processing of a very high Tg polymer, the PNBE homopolymer has, to our knowledge, never found any use.
Functional polynorbornenes (PNBEs) have been the object of considerable scrutiny for the last 20 years, because they combine the high Tg imparted by the bicyclic rigid repeat unit as well as desirable properties endowed by their functionalities.8,9,10 NBE monomers are obtained from rather simple and inexpensive feedstocks, using a one-step Diels-Alder reaction between cyclopentadiene and a functionalized dienophile. However, the Diels-Alder reaction leads to two stereoisomers, endo and exo, which have very different reactivities.11,12 In fact, the endo stereoisomer is less reactive than exo form and deactivates the catalyst.11,12 Thus, in the past, the preparation of functional polynorbornenes usually required the separation of the endo and exo stereoisomers, and only the exo stereoisomer was used. Such a separation procedure was time-consuming, and led to the accumulation of unreacted endo stereoisomers as undesirable waste.
Recently we have shown that the polymerization of functionalized NBEs containing both stereoisomers is in fact feasible.13 We have thus been able to prepare a variety of substituted PNBEs, containing functional groups such as esters, anhydrides, aldehydes, imides, alcohols and double bonds. Due to their high Tg and functionality, these polymers show desirable properties. We describe here two methods to prepare functional polymers. The first one leads to the synthesis of the water soluble polymer poly(5-norbornene-2-carboxylic acid), PNBE(CO2H), using a cationic Pd catalyst (Figure 1).13,14 The same polymerization method can be used to prepare functional PNBEs with various pendant functionalities, such as esters, alcohols, imides, bromo-alkyls, aldehydes and anhydrides. In our hands, this cationic Pd catalyst cannot be used for NBEs containing pendant double bonds such as 5-vinyl-2-norbornene. In this case, a partial insertion of the pendant double bond during the polymerization leads to the formation of a cross-linked material. Therefore, we present here a second method dedicated to the formation of poly(5-vinyl-2-norbornene), PNBE(vinyl), using Pd2(dba)3:AgSbF6:PPh3 as an in situ catalyst.14 The pendant vinyl groups of the polymer are then further epoxidized, to lead to the formation of PNBE(epoxy) (Figure 1). Both PNBE(CO2H) and PNBE(epoxy) have been found to lead to the formation of thermoset resins with a Tg as high as 350 &#176;C.14 Thus, the simple method described here allows one to efficiently prepare polymers with a very high Tg and having a variety of functional groups, which can be used for numerous applications.
<img alt="Figure 1" src="/files/ftp_upload/54552/54552fig1.jpg" /> 
Figure 1: Functional PNBEs prepared by Pd catalyzed polymerization. (A) preparation of PNBE(CO2H), (B) preparation of PNBE(vinyl) and PNBE(epoxy). The dashed bond indicates a mixture of endo and exo isomers. <a href="http://cloudflare.jove.com/files/ftp_upload/54552/54552fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="0" cellpadding="0" cellspacing="0" width="945">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">acrylic acid</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">147230</td>
			<td style="width:299px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">hydroquinone</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td>H9003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">dicyclopendadiene</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td align="left">454338</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">palladium allyl dichloride dimer</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td>222380</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">silver hexfluoro antimonate</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">227730</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">liquid nitrogen</td>
			<td style="width:241px;">Local Facility</td>
			<td style="width:135px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">ethyl acetate</td>
			<td style="width:241px;">Fischer Scientific</td>
			<td>E14520</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">5-vinyl-2-norbornene</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">148679</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">toluene</td>
			<td style="width:241px;">Fischer Scientific</td>
			<td>T290-4</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">palladium dba</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">227994</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">triphenyl phosphine</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">93090</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">silica gel 40-63 microns</td>
			<td style="width:241px;">Silicycle</td>
			<td style="width:135px;">Siliaflash</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">methanol</td>
			<td style="width:241px;">Fischer Scientific</td>
			<td>BPA412-20</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">dichloromethane</td>
			<td style="width:241px;">EMD Millipore</td>
			<td>DX08311</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">formic acid</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">F0507</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">acetic acid</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td>320099</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:271px;">hydrogen peroxide solution</td>
			<td style="width:241px;">Sigma-Aldrich</td>
			<td style="width:135px;">216763</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:271px;">acetone</td>
			<td style="width:241px;">Fischer Scientific</td>
			<td>A18-200</td>
			<td></td>
		</tr>
	</tbody>
</table>

a simple and efficient protocol for the catalytic insertion polymerization of functional norbornenes

Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic nature of the monomer is conserved. The resulting polymer, polynorbornene, has a very high glass transition temperature, Tg, and interesting optical and electrical properties. However, the polymerization of functional norbornenes by this mechanism is complicated by the fact that the endo substituted norbornene monomer has, in general, a very low reactivity. Furthermore, the separation of the endo substituted monomer from the exo monomer is a tedious task. Here, we present a simple protocol for the polymerization of substituted norbornenes (endo:exo ca. 80:20) bearing either a carboxylic acid or a pendant double bond. The process does not require that both isomers be separated, and proceeds with low catalyst loadings (0.01 to 0.02 mol%). The polymer bearing pendant double bonds can be further transformed in high yield, to afford a polymer bearing pendant epoxy groups. These simple procedures can be applied to prepare polynorbornenes with a variety of functional groups, such as esters, alcohols, imides, double bonds, carboxylic acids, bromo-alkyls, aldehydes and anhydrides.

The NBE monomers are prepared by simple Diels-Alder reaction of DCPD and a suitable dienophile, for example acrylic acid (AA). Normally, DCPD is cracked to yield cyclopentadiene (CPD) before reaction.17 Freshly cracked CPD is then engaged in the Diels-Alder reaction. However, in this protocol, both cracking and Diels-Alder steps are performed concomitantly, in a one-pot reaction. Thus, as soon as CPD is formed, it reacts with AA to yield 5-norbornene-2-carboxylic a...

Watch this Scientific Journal Video about A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes at JoVE.com

A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes (Video) | JoVE

We describe the catalytic insertion polymerization of 5-norbornene-2-carboxylic acid and 5-vinyl-2-norbornene to form functional polymers with a very high glass transition temperature.

A Simple and Efficient Protocol for the Catalytic Insertion Polymerization of Functional Norbornenes

Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic ...

Research

Education

JoVE Journal

JoVE Core

Chemistry

Biochemistry

SCIENTISTS IN ACTION

A Simple and Rapid Protocol for Measuring Neutral Lipids in Algal Cells Using Fluorescence

A Simple and Rapid Protocol for Measuring Neutral Lipids in Algal Cells Using Fluorescence (Video) | JoVE

Algae are considered excellent candidates for renewable fuel sources due to their natural lipid storage capabilities. Robust monitoring of algal ...

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica (Video) | JoVE

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

Facile and Efficient Preparation of Tri-component Fluorescent Glycopolymers via RAFT-controlled Polymerization

Facile and Efficient Preparation of Tri-component Fluorescent Glycopolymers via RAFT-controlled Polymerization (Video) | JoVE

Synthetic glycopolymers are instrumental and versatile tools used in various biochemical and biomedical research fields. An example of a facile and ...

Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization

Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization (Video) | JoVE

We demonstrate a method for high-throughput catalyst screening using a parallel pressure reactor starting from the initial synthesis of a nickel ...

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst (Video) | JoVE

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The ...

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives

Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives (Video) | JoVE

Molecules bearing trifluoromethoxy (OCF3) group often show desired pharmacological and biological properties. However, facile synthesis of ...

A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating

A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating (Video) | JoVE

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic by a simple spray ...

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst (Video) | JoVE

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group (Video) | JoVE

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient ...

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area (Video) | JoVE

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of ...