RAFは、この作業のサポートのための国立科学財団（CHE-0844946）を感謝します。

1。 SMIの合成2（0.1M） <ol><li>炎は50 mlの丸底フラスコを乾燥し、アルゴンでそれをフラッシュします。攪拌棒を追加して、セプタム付きフラスコをカバーしています。サマリウム金属（0.2グラム、1.3ミリモル）を秤量し、再びアルゴンでフラスコを洗い流し、フラスコに加える。 </li><li>ヨウ素結晶（0.254グラム、2.0ミリモル）を添加した10mlの乾燥、完全に脱気テトラヒドロフラン（THF）を追加します。セプタムを通してアルゴンバルーンを追加し、これは反応にAr雰囲​​気の正圧を維持します。 </li><li> 3時間以上にわたって室温で激しく溶液を攪拌。 SMI 2が生成されるソリューションは、色の変化の様々な通過、オレンジはイエロー（45分）、そして最終的には青に変わり、緑（1時間）が続いている。 </li><li>最後の濃紺色は、電離サマリウムが形成されていることを示しています。完全な変換を保証するために、合成にSMI 2を使用する前に、少なくとも3時間のためのソリューションをかき混ぜる。 </li></ol> 2。 SAmariumバルビエ反応 - ヘキサメチルホスホルアミド（HMPA）加算<ol><li> SMI 2-HMPA複合体を作るために、アルゴン下で作りたてのSMI 2（10ミリリットル、0.1M、1.0mmol）を取ると、アルゴン下、シリンジ、滴下を通じて、HMPAの1.75ミリリットル（10当量、10ミリモル）を追加します。深い紫色のカラーフォーム。 </li><li>別々にアルゴン、アドインiodododecane（0.45ミリモル、110μl）を、3 - ペンタノン（0.45ミリモル、48μL）と乾燥THF 2mlの下に、きれいな乾いたバイアルインチ</li><li> SMI 2 / HMPA複雑に滴下した基質溶液の混合物を追加。 </li><li>攪拌の5分以内に、紫の色は、反応の終了を示す、曇りを見て開始されます。 </li><li>反応が完了した後、それをクエンチする空気への解決策を公開していると黄色に色更なる変化を攪拌する際に。 </li><li>次いで、この反応物を、飽和塩化アンモニウム水溶液で洗浄することにより後処理する。分液漏斗に溶液を加え、ジエチルエーテル（5ml）を追加します。激しく振とうした後に取り外すトップ有機層を、より多くのジエチルエーテルを加える。水層からさらに2回抽出し、有機層のすべてを兼ね備えています。 </li><li>チオ硫酸ナトリウム水溶液の飽和溶液を用いて有機層を洗浄します。水、次いでブラインで最終洗浄で洗浄、続いて底水層を削除します。トップ有機層を取得し、溶液中に存在する水のいずれかの最後の量を吸収するために硫酸マグネシウムを追加します。 </li><li>過剰HMPAを除去するために、フロリジルのプラグを通してソリューションを渡します。 </li><li>バルビエの製品を得るために、ロータリーエバポレーターで溶液を濃縮。製品はGCMS及び1 H-NMRにより同定した。23 </li></ol> 3。サマリウムバルビエ反応-のNi（acac）の2触媒<ol><li>のNi（acac）の2（1モル％、0.01ミリモル、0.0026グラム）秤量し、アルゴン下、脱気したTHFの3ミリリットルを含む、きれいな乾いたバイアルに追加します。作りたてのsにシリンジでのNi（acac）の2液を加え0.1MのSMI 2（1.0ミリモル、10ミリリットル）のolution。 </li><li>別々にアルゴン、アドインiodododecane（0.45ミリモル、110μl）を、3 - ペンタノン（0.45ミリモル、48μL）と乾燥THF 2mlの下に、きれいな乾いたバイアルインチ</li><li> SMI 2 / Niの混合物に滴下した基質溶液を加える。 </li><li>攪拌の15分以内に、青い色は、反応の終了を示す黄緑の色を形成するために消費します。 </li><li>反応が完了した後、それをクエンチする空気への解決策を公開していると黄色に色更なる変化を攪拌する際に。 0.1Mの水溶液で洗浄することにより反応を操作する。塩酸（3ミリリットル）。分液漏斗に溶液を加え、ジエチルエーテル（5ml）を追加します。 </li><li>硫酸マグネシウムで乾燥した後、チオ硫酸ナトリウム、水および食塩の水溶液で前述した、およびプロトコルを使用して有機層を洗浄します。バルビエ生成物を得るための解決策を集中する。製品はGCMS及び1 H-NMRにより同定することができる。28 </sアップ&gt; </li></ol>

<ol>
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特別な利害関係は宣言されません。

最も一般的な添加剤の2つを使用して、SMI 2溶液と有機合成への応用を生成するための簡単な手順は、ここに提示されます。二つの例は、微調整するために反応SMI 2の反応性のメカニズムの理解の重要性を描く説明。反応機構の基盤の知識は、彼らの反応の要件に従って、合成化学者に適応させるために、この試薬を使用することができます。 この単一電子均質還元剤は取り扱いが容易であり、商業的供給源から購入することができます。上記のプロトコルは、不活性条件下で行われたときにまっすぐ進むのですが、一般的なトラブルシューティング手順の一部は、（a）SM金属が空気に長時間さらされることがあったかどうか（b）は、それが持っている可能性があり、THFを適切に脱気し、乾燥していることを確認し層の外側に酸化された、きれいな金属面を露出させるために乳鉢とpestal、（c）で金属を挽く難乾燥アルゴン下ですべてのガラス製品とクールは、（d）の後に金属と相互作用することが示されているようにアルゴン、窒素を介して不活性雰囲気を好まれる（e）には、Sm-金属過剰の存在は、SMIの濃度を維持するのに役立ちます2、（f）はresublimeヨウ素結晶。

<table border="1"><tbody><tr><td> 試薬の名称 </td><td> 会社 </td><td> カタログ番号 </td><td> コメント（オプション） </td></tr><tr><td>サマリウム金属</td><td>アクロス</td><td> 29478-0100 </td><td> -40メッシュ、99.9％（金属ベース） </td></tr><tr><td> THF </td><td> OmniSolv </td><td> TX0282-1 </td><td>革新的な技術溶媒精製システムを通して精製した。あるいは、それは無料 - ポンプ - 解凍法により脱気することができる</td></tr><tr><td>ヨウ素</td><td> Alfa Aesar社</td><td> 41955から22 </td><td> Resublimed結晶、99.8％ </td></tr><tr><td> Iodododecane </td><td>アクロス</td><td> 25009-0250 </td><td> 98パーセント</td></tr><tr><td> 3 - ペンタノン</td><td> Alfa Aesar社</td><td> AAA15297-AE </td><td> 99パーセント</td></tr><tr><td> HMPA </td><td> Alderich </td><td> H11602 </td><td> 98パーセント、アルゴン下でのCaOから抜き出す</td></tr><tr><td> NII 2 </td><td> Alfa Aesar社</td><td> 22893 </td><td> 99.5％（金属ベース） </td></tr></tbody></table>

preparation and use of samarium diiodide (smi2) in organic synthesis: the mechanistic role of hmpa and ni(ii) salts in the samarium barbier reaction

最初は難解な試薬と見なされますが、SMI 2は有機合成化学のための共通のツールとなっています。 SMI 2を、THF中サマリウム金属に分子状ヨウ素を添加することによって生成されます。1,2-3は、それが軽度であり、選択的な単一電子還元剤であり、その多様性は、CC結合を含む削減の広い範囲を開始する能力の結果である形成し、カスケードまたは逐次反応。 SMI 2スルホキシドおよびスルホンを含む様々な官能基、ホスフィンオキシド、エポキシド、アルキルおよびアリールハライド、カルボニル、共役二重結合を減らすことができます。SMI-2媒介反応の魅力的な特徴の一つは、2月12日の能力である共溶媒または添加剤の選択的な使用を通して反応の結果を操作します。ほとんどのインスタンスでは、添加剤は、還元率と化学療法または反応の立体選択性を制御する上で不可欠である13〜14添加物の共mmonly SMI 2の反応性は3つの主要なグループに分類することができる微調整するために利用されます：（1）ルイス塩基（HMPA、他の電子供与配位子、キレートエーテル等）、（2）プロトン源（アルコール、水等）、（3）無機添加ニッケル（Ni（acac）の2、FeCl 3を 、等）。3 SMI 2反応の機構と添加剤の役割を理解することは、有機合成の試薬 ​​の全潜在能力を利用できます。この反応におけるHMPAとNi（II）：SM-バルビエ反応は2の一般的な添加剤の合成の重要性と機構的役割を説明するために選択されています。サマリウム·バルビエ反応は、ハロゲン化アルキル、カルボニル、及びSmの還元剤がワンポットで同時に混合していることが唯一の違いと伝統的なグリニャール反応に似ていますカップリングパートナーの範囲を使用してSMを媒介バルビエ反応の1,15例報告されており、1,3,7,10,12とUTであった大型天然物合成の重要なステップでilized。SMI 2反応に対する添加剤の影響に関するこれまでの研究では、16,17 HMPA、より強力なを生産、サマリウム金属中心に配位することによってSMI 2の還元電位を高めることが示されている、 13-14,18は立体的に、その後の結合形成を促進するイベントのポスト電子伝達手順の中で不可欠な役割を果たして還元19-21妨げといくつかのケースではSM-バルビエ反応では22が 、HMPAがさらにハロゲン化アルキルを活性化することが示されているプリ平衡ステップで複合体を形成することにより、図23 ニッケル（II）塩はSm媒介変換で頻繁に使用される触媒添加剤です。成功のための重要なものの24から27は、Ni（II）の機構的な役割は、これらの反応では知られていなかった。最近では、SMI 2は、Ni（0）にNi（II）を減少させ、次いで、反応物をorganomeを介して行われることが示されているtallicニッケル（0）化学28 これらの機構の研究は、同じバルビエ生成物が得られるが、SMI 2反応における様々な添加剤の使用が急激に反応機構経路を変更することを強調している。これらのSMI-2開始反応を実行するためのプロトコルが記載されている。

図1は、サマリウム·バルビエ反応を示しています。無添加を使用してSMを媒介反応は72時間かかり、残りの出発物質であると、所望の生成物の69％を得た。 10人以上の当量を加えた。 HMPAの反応はほぼ定量し、数分以内に完了する。15,23が 1モル％のNi（acac）の2の添加により、反応が収率97％で、15分以内に完了しています28 （HMPA）4 - HMPAは、SMI 2、共溶媒変位SMI 2を形成するための協調のTHFに追加されたとき。さらにHMPA（当量6-10）を追加すると、ヨウ化物イオンは外球（ 図2）に変位している19〜21力学的研究はHMPAをSm-バルビエ反応で使用される場合に補助溶媒にも作用することを示すsを活性化し、炭素 - ハロゲン結合を伸長複合体を形成し、ハロゲン化アルキル基材とのSMによって減少します（ 図3）、それが影響を受けやすくpecies。 HMPAの役割のこの詳細な理解を通じて、HMPAとはSm-バルビエ反応のための機構（ 図4）が提案された。プレ平衡工程で形成された23ハロゲン化アルキル-HMPA複合体が形成するSM / HMPA減額される律速段階でラジカル。ラジカルはカルボニルととプロトン化時のカップルは最終的な製品を生み出すorganosamarium種を形成し、さらに還元を受ける。 ニッケル（II）を添加した場合に、SMI 2が最初に基板のいずれかの減少よりも優先してニッケル（0）にNi（II）を低減します。運動と機構の研究に基づいて、以下のメカニズムが（ 図5）が提案された。有機ニッケル種を形成するハロゲン化アルキル債券に28 SMI 2で還元した後、水溶性ニッケル（0）が種を挿入します。 Smの高度oxophilic性質（III）によって駆動される<html>触媒サイクルにorganosamarium中間リリースのNi（II）の背中を形成するために、transmetallation。その後organosamariumカルボニルと結合し、プロトン化時には、目的の第三級アルコールを形成している。それはまた、ニッケル（0）ナノ粒子はNiのSmを媒介削減（Ⅱ）を貫通して形成されていることが観察されたが、これらの粒子は不活性であり、触媒の不活性化の源であることが判明した。 <img alt="図1" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig1highres.jpg" src="/files/ftp_upload/4323/4323fig1.jpg" /> iodododecaneと3 -ペンタノン、 図1。サマリウム·バルビエ反応。 <img alt="図2" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig2highres.jpg" src="/files/ftp_upload/4323/4323fig2.jpg" /> 図2：SMI 2-HMPA複合体。 ontent &quot;のfo：キープtogether.withinページ=&quot; always &quot;を&gt; <img alt="図3" fo:content-width="3.5in" fo:src="/files/ftp_upload/4323/4323fig3highres.jpg" src="/files/ftp_upload/4323/4323fig3.jpg" /> 図3 HMPA及びアルキルヨウ化物錯体。 <img alt="図4" fo:content-width="4.5in" fo:src="/files/ftp_upload/4323/4323fig4highres.jpg" src="/files/ftp_upload/4323/4323fig4.jpg" /> 図4過剰HMPAとサマリウム·バルビエ反応のための提案されたメカニズム。 <img alt="図5" fo:content-width="4in" fo:src="/files/ftp_upload/4323/4323fig5highres.jpg" src="/files/ftp_upload/4323/4323fig5.jpg" /> 図5触媒のNi（II）を含むサマリウムバルビエ反応のための提案されたメカニズム。

Watch this Scientific Journal Video about Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction at JoVE.com

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

二ヨウ化サマリウム（SMIの準備のための簡単​​な手順<sub&gt; 2</sub&gt;）のTHFが記載されている。 （ACAC）すなわちヘキサメチルホスホルアミド（HMPA）とNi 2主な添加剤の役割<sub&gt; 2</sub&gt; SMを介した反応でSM-バルビエ反応で実証されています。

二ヨウ化サマリウム（SMIの調製および使用<sub&gt; 2</sub&gt;）有機合成における：サマリウムバルビエ反応におけるHMPAとNi（II）塩の力学的役割

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of ...

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Chemistry

Preparation and Use of Samarium Diiodide (SmI2) in Organic Synthesis: The Mechanistic Role of HMPA and Ni(II) Salts in the Samarium Barbier Reaction

32.6K ビュー.  Lehigh University. 二ヨウ化サマリウム（SMIの準備のための簡単​​な手順 2）のTHFが記載されている。 （ACAC）すなわちヘキサメチルホスホルアミド（HMPA）とNi 2主な添加剤の役割 2 SMを介した反応でSM-バルビエ反応で実証されています。

ビデオ: Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

The development of fluorescent indicators represented a revolution for life sciences. Genetically encoded and synthetic fluorophores with sensing abilities allowed the visualization of biologically relevant species with high spatial and temporal resolution. Synthetic dyes are of particular interest thanks to their high tunability and the wide range of measureable analytes. However, these molecules suffer several limitations related to small molecule behavior (poor solubility, difficulties in targeting, often no ratiometric imaging allowed). In this work we introduce the development of dendrimer-based sensors and present a procedure for pH measurement in vitro, in living cells and in vivo. We choose dendrimers as ideal platform for our sensors for their many desirable properties (monodispersity, tunable properties, multivalency) that made them a widely used scaffold for several biomedical devices. The conjugation of fluorescent pH indicators to the dendrimer scaffold led to an enhancement of their sensing performances. In particular dendrimers exhibit reduced cell leakage, improved intracellular targeting and allow ratiometric measurements. These novel sensors were successfully employed to measure pH in living HeLa cells and in vivo in mouse brain.

Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors

Fluorescence sensors are powerful tools in life science. Here we describe a methodology to synthesize and use dendrimer-based fluorescent sensors to measure pH in living cells and in vivo. The dendritic scaffold enhances the properties of conjugated fluorescent dyes leading to improved sensing properties.

合成、細胞の配送および<em&gt;インビボ</em&gt;デンドリマーベースのpHセンサの応用

The development of  fluorescent indicators represented a revolution for life sciences. Genetically  encoded and synthetic fluorophores with sensing ...

化学

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. Isonicotinic acid, or its derivatives, are coupled to variable length diaminoalkane chains under an inert atmosphere in anhydrous DMF or DMSO with the use of a weak base, triethylamine, and a coupling agent, 1-propylphosphonic anhydride. The products precipitate from solution upon formation or can be precipitated by the addition of water. If desired, the ligands can be further purified by recrystallization from hot water. Dinuclear platinum complex synthesis using the bispyridine ligands is done in hot water using transplatin. The most informative of the chemical characterization techniques to determine the structure and gross purity of both the bispyridine ligands and the final platinum complexes is 1H NMR with particular analysis of the aromatic region of the spectra (7-9 ppm). The platinum complexes have potential application as anticancer agents and the synthesis method can be modified to produce trinuclear and other multinuclear complexes with different hydrogen bonding functionality in the bridging ligand.

This protocol describes the use of amide coupling reactions of isonicotinic acid and diaminoalkanes to form bridging ligands suitable for use in the synthesis of multinuclear platinum complexes, which combine aspects of the anticancer drugs BBR3464 and picoplatin.

ビスピリジン系リガンドの合成と二核抗癌剤として白金彼らの複合体形成のためのアミドカップリング反応

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. ...

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.

官能化有機金属構造体の合成とキャラクタリゼーション

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

Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures in multi-gram scale quantities. The goal of this manuscript is to clearly detail how to handle and prepare these unique carbenes such that a synthetic chemist of any skill level can work with them. The two carbenes described are a diamidocarbene (DAC, carbene 1) and a monoamidoaminocarbene (MAAC 2). These carbenes are highly electron-deficient and as such display reactivity profiles that are atypical of more traditional N-heterocyclic carbenes. Additionally, these two carbenes only differ in their electrophilic character and not their steric parameters, making them ideal for studying how carbene electronics influence reactivity. To demonstrate this phenomenon, we are also describing the activation of white phosphorus (P4) using these carbenes. Depending on the carbene used, two very different phosphorus-containing compounds can be isolated. When the DAC 1 is used, a tris(phosphaalkenyl)phosphane can be isolated as the exclusive product. Remarkably however, when MAAC 2 is added to P4 under identical reaction conditions, an unexpected carbene-supported P8&#160;allotrope of phosphorus is isolated exclusively. Mechanistic studies demonstrate that this carbene-supported P8allotrope forms via a [2+2] cycloaddition dimerization of a transient diphosphene which has been trapped by treatment with 2,3-dimethyl-1,3-butadiene.

Here, we present a protocol for the synthesis of two carbonyl-decorated carbenes. The protocol makes these interesting compounds readily available to chemists of all skill levels. In addition to the synthesis of these two carbenes, their use in the activation of white phosphorus is also described.

白リンの活性化カルボニル装飾カルベンの調製および使用

Here we present a protocol for the synthesis of two distinct carbonyl-decorated carbenes. Both carbenes can be prepared using nearly identical procedures ...

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.

アシル塩化物およびカリウムAlkynyltrifluoroborate塩からYnonesの金属を含まない合成

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

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

ナノサイズ一ナトリウムチタン酸の合成と反応化学

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

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.

超分子コロイドの合成とキャラクタリゼーション

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

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

タンパク質のバイオコンジュゲートの合成<em&gt;経由で</em&gt;システイン - マレイミドケミストリー

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

単一分子レベルでの環状ポリマーの合成と溶融状態におけるそれらの拡散運動のキャラクタリゼーション

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. Detailed and generalized protocols are also presented for testing the catalytic activity of such complexes in arylation and Suzuki-Miyaura cross-coupling reactions. Representative results are shown for the catalytic activity of the four complexes in arylation and Suzuki-Miyaura type reactions. For each of the reactions investigated, at least one of the four complexes successfully catalyzed the reaction, qualifying them as promising candidates for catalysis of many carbon-carbon bond-forming reactions. The protocols presented are general enough to be adapted for the synthesis, purification and catalytic activity testing of new palladium N-heterocyclic carbene complexes.

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. The complexes were tested for catalytic activity in arylation and Suzuki-Miyaura reactions. For each reaction investigated, at least one of the four complexes successfully catalyzed the reaction.

パラジウム<em&gt; N</em&gt; - 複素環カルベン錯体：ベンズイミダゾリウム塩からの合成と炭素 - 炭素結合形成反応における触媒活性

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from ...