Name: sulfate separation by selective crystallization with a bis-iminoguanidinium ligand
Uploaded: 2016-09-08T13:00:00.000+00:00
Duration: 8 min 1 s
Description: Watch this Scientific Journal Video about Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand at JoVE.com

This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division. We thank the University of North Carolina Wilmington for providing the seawater.

1. 합성 1,4- 벤젠 비스 (iminoguanidinium) 클로라이드 (BBIG-CL) <ol><li> 제자리 1,4- 벤젠 비스 (iminoguanidinium) 염화물 리간드 (BBIG-CL)의 합성 및 황산염과의 결정화에 <ol><li> 자기 교반 바가 장착 된 25 mL의 둥근 바닥 플라스크에 0.067 테레프탈 g 및 탈 이온수 10 ㎖에 aminoguanidinium 클로라이드의 0.5 M 수용액 2.2 mL를 추가. </li><li> 20 ℃에서 4 시간 동안 자기 적으로 교반 용액. 이 BBIG-CL의 약간 황색 용액을 얻을 것입니다. </li><li> 황산나트륨의 1 M 수용액 0.5ml를 추가. 이것은 결정 성 백색 고체로서 BBIG-SO (4)의 바로 침전 될 것이다. </li><li> BBIG-SO 4를 복구하여 고체를 진공 여과 필터. 순수한 황산 염을 얻기 위해 여과지에 물 5ml 분취 량으로 5 회 고체를 세척한다. </li><li> 결정 BBIG-SO의 위상 순도를 확인 <sub&gt; 4 분말 X 선 회절에 의해 얻어진 12. 도 1에 도시 된 패턴을 비교한다. </li></ol></li><li> 1,4- 벤젠 비스의 예 제자리 합성 (iminoguanidinium) 염화물 (11) <ol><li> 테레프탈 4 g 및 50 ml의 자기 교반 바가 장착 된 둥근 바닥 플라스크에 에탄올 20 ㎖에 aminoguanidinium 클로라이드 7.26 g을 추가한다. </li><li> 핫 플레이트를 사용하여 60 ° C에 대한 해결책을 가열하고, 2 시간 동안 자기 교반 막대로 저어. 20 ℃로 용액을 냉각시키고, 그 후, 3 시간 동안 앉아 필터 페이퍼 장착 흡인 여과기를 통해 진공 여과에 의해 고체를 수집하자. </li><li> 비등까지 핫 플레이트상에서 에탄올 및 열이 고체를 20 mL의 일시. 고체가이 시점에서 용액에 완전히 들어 가지 않을 경우 모든 고체가 용해 될 때까지 매번 비등 온도에 도달하는 용액을 허용 에탄올 작은 분취 량 (1 ㎖)에 추가한다. </li><li> 플라스크 실내 temperatu으로 냉각 할 수 있도록 허용다음 하룻밤 0 ° C의 냉동고에 배치 다시. 진공 여과법을 사용하여 흡인 여과기를 구비 한 필터 종이를 통해 여과하여 고체를 수집한다. </li><li> 1 H NMR 분광법 (13)에 의해 BBIG-CL의 정체성과 순도를 확인합니다. 도 2에 도시 된 스펙트럼과 비교한다. </li></ol></li></ol> 해수 2. 황산 분리 <ol><li> BBIG-SO 4로 황산염 결정 주 : 황산 제거 할 필요 BBIG-CL의 양은 해수 황산의 정확한 양에 의존한다. 그것은 황산의 99 % 제거에 황산 결과 BBIG-CL 상대의 1.5 당량을 사용하는 것으로 나타났습니다. BaCl 2 적정에 의해 측정 된이 프로토콜에 사용 된 해수는 30 mM의 황산의 농도를 갖는다. <ol><li> 부유 분진 및 생체 유기물을 제거하는 작은 기공 크기 0.22 μm의 주사기 필터 나 여과막과 해수 필터. </li><li> 30 확인이전 섹션에 기술 된 바와 같이 제조 된 탈 이온수 및 고체 BBIG-CL을 사용 BBIG-CL의 MM의 솔루션입니다. </li><li> 1 (v / v)의 비율 : 1.5의 해수에 BBIG-CL 솔루션을 추가합니다. </li><li> 황산 정량 (&gt; 99 %) 제거를 보장하기 위해 몇 시간 동안 교반한다. </li><li> 진공 여과법을 사용하여 흡인 여과기를 구비 한 필터 종이를 통해 여과하여 고체를 수집한다. 물 5 mL를 분취하여 여과지에 5 회 고체를 세척한다. </li><li> 진공에서 분리 된 고체를 건조 수율을 결정하는 데 무게. </li></ol></li><li> 리간드 복구 <ol><li> 자기 교반 막대가 구비 된 20 ㎖ 섬광 바이알 중의 NaOH (10 %)의 2 ml의 용액에 BBIG-SO 4 53.1 mg의 추가. </li><li> 20 ° C에서 2 시간 동안 혼합물을 교반한다. 약간 노란색 침전물을 형성 할 것이다. </li><li> 진공 여과법을 사용하여 흡인 여과기를 구비 한 필터 종이를 통해 고체를 필터. 0.2 여과지상의 고체를 씻어ml의 물, 진공하에 건조. </li><li> 비스 (구아니딘) 유리 염기로서 정체성을 확인하는 NMR (13)에 의해 회수 된 고체의 특성을. 도 3에 도시 된 NMR 스펙트럼과 비교한다. </li></ol></li><li> 액체 섬광 계수를 β에 의한 해수에서 제거 황산의 양의 결정 주의 :이 기술은 일반적으로 대부분의 실험실에서 발생되는 것보다 위험 다른 클래스 포즈 방사성 동위 원소의 사용을 포함한다. 방사성 핵종을 처리 할 때 특수 방사선 보호 장비는 일반적으로 필요합니다. 따라서, 절차가주의 깊게 뒤에 있고 안전 책임자가 조언 및 지침에 대한 상담을하는 것이 필수적이다. <ol><li> (CI를 다음 식 (CPM 및 큐리을 사용하여 해수 용액 밀리리터 분 (CPM) 당 500 만 카운트,이 있는지 확인하기 위해 사용되는 황-35 동위 원소 (5 mCi의 / ㎖)의 스톡 용액의 부피를 계산 ) 측정 (F)의 두 단위또는 방사능) <img alt="식 (1)" src="/files/ftp_upload/54411/54411eq1.jpg" /> <img alt="식 (2)" src="/files/ftp_upload/54411/54411eq2.jpg" /> <img alt="식 (3)" src="/files/ftp_upload/54411/54411eq3.jpg" /></li><li> 35 S 방사성 황산나트륨 용액 5.0 mCi의 / ㎖ 용액 0.0112 mL로 해수 25 ㎖의 스파이크. </li><li> 탈 이온수 BBIG-CL의 0, 15, 30, 33, 45 및 60 mM의 용액을 제조하고 35 S-방사성 황산 동량이 용액 0.750 ㎖의 결합은 2 mL의 원심 분리 관으로 해수 아군. </li><li> 24 시간 동안 25 ± 0.2 ° C의 일정한 온도로 유지 인큐베이터 / 공기 창에 회전 휠 또는 소용돌이를 통해 혼합물을 저어. </li><li> 25 ° C에서 10 분 동안 1,500 XG에 용액을 원심 분리기. </li><li> 원심 분리 후, 주사기를 이용하여 각 용액의 1.2 ml의 제거 후 현탁 제거 0.22 μm의 주사기 필터를 통해 필터링<html> 침전물. 피펫 폴리 프로필렌 섬광 유리 병에 섬광 칵테일 20 ㎖에 이러한 솔루션의 각 1.0 ml의. 더 BBIG-CL (제어 용액)을 함유하지 않는 용액을 사전 섬광 칵테일을 첨가 탈 이온수로 10 배 희석한다. </li><li> 샘플 및 액체 섬광 계수기에서 섬광 칵테일을 함유하는 신틸레이션 바이알을 놓고 그 전에 어두운 적응 샘플을 허용 카운트에 1 시간 방치. 참고 : 이전에 샘플을 계산에 악기를 보정하고 각각의 샘플은 30 분 동안 계산 할 수 있습니다. 용액을 황산의 농도를 결정할 때 사용되는 배경 보정을 허용하기 위해서 단지 섬광 칵테일을 함유하는 바이알을 추가 개수. </li><li> 다음 식을 사용하여 제거 황산의 양을 결정 : <img alt="식 (4)" src="/files/ftp_upload/54411/54411eq4.jpg" /> 54411 / 54411eq5.jpg &quot;/&gt; <img alt="식 (6)" src="/files/ftp_upload/54411/54411eq6.jpg" /></li></ol></li></ol>

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The authors have nothing to disclose.

이 기법은 매우 강력하게 기입 절차에 많은 편차가 아니라 저항성이다. 따라야하지만 두 가지 중요한 단계가 있습니다. 우선, BBIG-CL 리간드 가능한 순수 할 필요가있다. 불순물만을 결정화하고, 생성 된 황산염의 용해도에 영향을 미치지 않을 것, 또한 어려운 용액으로부터 정량 황산 제거를 위해 필요한 양을 계산하게된다. 이 기술은 미묘한 변화에 매우 민감 할 수 있기 둘째, β 액체 섬광 카운?...

경쟁 수용액에서 친수성 oxoanions (예를 들어, 황산염, 크롬 산염, 인산염)의 선택적 분리 환경 개선에 관련성, 에너지 생산, 인간의 건강에 근본적인 도전을 나타냅니다. 1,2 황산을 특히 물에서 인해 추출하기 어려운 그 고유의 자기 저항은 수화 영역을 흘리다 덜 극성 환경으로 마이그레이션 할 수 있습니다. 3 수성 황산 추출을보다 효율적으로 만들기 일반적으로 합성 종종 독성 시약 및 용매를 포함, 정화 어렵고 지루한 복잡한 수용체를 필요로합니다. 4,5 선택적 결정화가 물에서 분리 황산염 할 수있는 간단하면서도 효과적인 대안을 제공합니다. 6-9 등 바 2 +, 납 2+, 또는 라 2+ 형태로 매우 불용성 황산 염과 같은 일부 금속 양이온, 황산 분리에서의 사용은 항상 실제 아니지만 그들의 높은 toxi에도시 때로는 낮은 선택도. 황산 침전제로 유기 리간드를 사용하는 유기 분자 특성 설계 구조적 다양성과 가공성을 활용합니다. 수성 황산 결정화를위한 이상적인 유기 리간드는 수용성 아직 상대적으로 짧은 시간에 그리고 경쟁 이온의 높은 농도의 존재 하에서 불용성 페이트 염 또는 복합체를 형성한다. 또한, 합성 및 재활용이 용이해야한다. 그러한 리간드, 1,4- 벤젠 비스 (iminoguanidinium) (BBIG) 자기 조립 개의 시판 전구체 테레프탈 및 aminoguanidinium 클로라이드 시츄 최근 수성 황산 분리에 매우 효과적인 것으로 밝혀졌다. 10 리간드 수용성 염화물 형태이며, 선택적으로 쉽게 간단한 여과에 의해 용액으로부터 제거 될 수있는 매우 불용성 염으로 황산 결정화된다. BBIG 리간드는 다음과 탈 양성자하여 복구 할 수 있습니다queous NaOH를 다른 분리 사이클에서 다시 수성 HCl과 염화 형태로 변환하고 재사용 할 수있는 중립 비스 iminoguanidine의 결정화. 물 황산을 제거하는이 리간드의 효능은 용액에 남아 황산 농도를 모니터링하는 음이온 미량의 정확한 측정을 할 수있는보다 진보 된 기술을 요구하는 더 이상 사소한 작업이되도록 크다. 이를 위해 β 액체 섬광 계수와 함께 방사성 35 S 황산 트레이서 기법은 일반적으로 액체 - 액체 추출 분리하여 이용하고, 최근 모니터링 황산 결정화 효과적인 것으로 입증 채용 하였다. (8) 이 프로토콜은 현장 상기 BBIG 리간드의 합성과 수용액에서 황산 염으로 결정화에서 하나의 냄비를 보여줍니다. 리간드 (11)의 전 현장 합성도 공동으로 제공됩니다사용할 준비가 될 때까지, 결정 형태로 저장 될 수 BBIG-CL 많은 양의 생산 nvenient 방법. 이전에 조제한 BBIG-CL 리간드를 이용하여 해수로부터 제거 황산염 다음 설명된다. 마지막으로, 35 S 표지 황산 해수 황산 농도를 측정 β 액체 섬광 계수의 사용을 입증한다. 이 프로토콜은 수성 음이온 분리를위한 선택적 결정화의 사용을 탐험에 크게 관심이있는 사람들에 대한 자습서를 제공하기위한 것입니다.

<table><tbody><tr><td>Terephthalaldehyde</td><td>Sigma</td><td>T2207</td><td></td></tr><tr><td>Aminoguanidinium Chloride</td><td>Sigma</td><td>#396494</td><td></td></tr><tr><td>Sodium Sulfate</td><td>Sigma</td><td>#239313</td><td></td></tr><tr><td>Barium Chloride</td><td>Sigma</td><td>#342920</td><td>Highly Toxic</td></tr><tr><td>Ethanol</td><td>Any</td><td></td><td>Reagent Grade (190 proof)</td></tr><tr><td>Sodium Hydroxide</td><td>EMD</td><td>SX0590-1</td><td></td></tr><tr><td>Hydrochloric Acid</td><td>Sigma</td><td>#258148</td><td></td></tr><tr><td>Filter Paper</td><td>Any</td><td>-</td><td>Any qualitative or analytical filter paper will work</td></tr><tr><td>Syringe Filter (0.22 &amp;#956;m)</td><td>Any</td><td>-</td><td>Nylon filter</td></tr><tr><td>&lt;sup&gt;35&lt;/sup&gt;S Labeled Sulfate</td><td>Perkin Elmer</td><td>NEX041005MC</td><td></td></tr><tr><td>Ultima Gold Scintillation Cocktail</td><td>Perkin Elmer</td><td>#6013329</td><td></td></tr><tr><td>Polypropylene Vials&amp;nbsp;</td><td>Any</td><td>-</td><td></td></tr><tr><td>Disposable Syringe (2-3 ml)</td><td>Any</td><td>-</td><td>Any disposable plastic syringe works</td></tr></tbody></table>

sulfate separation by selective crystallization with a bis-iminoguanidinium ligand

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, 1,4-benzene-bis(iminoguanidinium) (BBIG), is demonstrated. The ligand is synthesized as the chloride salt (BBIG-Cl) by in situ imine condensation of terephthalaldehyde with aminoguanidinium chloride in water, followed by crystallization as the sulfate salt (BBIG-SO4). Alternatively, BBIG-Cl is synthesized ex situ in larger scale from ethanol. The sulfate separation ability of the BBIG ligand is demonstrated by selective and quantitative crystallization of sulfate from seawater. The ligand can be recycled by neutralization of BBIG-SO4 with aqueous NaOH and crystallization of the neutral bis-iminoguanidine, which can be converted back into BBIG-Cl with aqueous HCl and reused in another separation cycle. Finally, 35S-labeled sulfate and &#946; liquid scintillation counting are employed for monitoring the sulfate concentration in solution. Overall, this protocol will instruct the user in the necessary skills to synthesize a ligand, employ it in the selective crystallization of sulfate from aqueous solutions, and quantify the separation efficiency.

BBIG-SO 4 (도 1)의 분말 X 선 회절 패턴은 결정화 된 고체의 ID 명백한 확인을 허용한다. 기준 한 대 얻어진 패턴을 비교할 때, 피크 강도가 피크 위치보다 중요하다. 기준에 표시된 모든 강한 피크가 얻어진 샘플에 존재해야한다. 기준 패턴 결석 샘플 강한 피크의 출현은 불순물의 존재를 나타낸다. 1 ...

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Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

비스 (iminoguanidinium) 리간드와 황산의 선택적 분리에서의 이용 현장 수성 합성을위한 프로토콜은 제공됩니다.

비스 - iminoguanidinium의 리간드 선택적 결정화에 의한 황산염 분리

A simple and effective method for selective sulfate separation from aqueous solutions by crystallization with a bis-guanidinium ligand, ...

sulfate-separation-selective-crystallization-with-bis

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8.3K 조회수.  Oak Ridge National Laboratory.  비스 (iminoguanidinium) 리간드와 황산의 선택적 분리에서의 이용 현장 수성 합성을위한 프로토콜은 제공됩니다. 

비디오: Sulfate Separation by Selective Crystallization with a Bis-iminoguanidinium Ligand

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography

The highly diastereoselective preparation of cis-N-Ts-iodoaziridines through reaction of diiodomethyllithium with N-Ts aldimines is described. Diiodomethyllithium is prepared by the deprotonation of diiodomethane with LiHMDS, in a THF/diethyl ether mixture, at -78 &#176;C in the dark. These conditions are essential for the stability of the LiCHI2 reagent generated. The subsequent dropwise addition of N-Ts aldimines to the preformed diiodomethyllithium solution affords an amino-diiodide intermediate, which is not isolated. Rapid warming of the reaction mixture to 0 &#176;C promotes cyclization to afford iodoaziridines with exclusive cis-diastereoselectivity. The addition and cyclization stages of the reaction are mediated in one reaction flask by careful temperature control.
Due to the sensitivity of the iodoaziridines to purification, assessment of suitable methods of purification is required. A protocol to assess the stability of sensitive compounds to stationary phases for column chromatography is described. This method is suitable to apply to new iodoaziridines, or other potentially sensitive novel compounds. Consequently this method may find application in range of synthetic projects. The procedure involves firstly the assessment of the reaction yield, prior to purification, by 1H NMR spectroscopy with comparison to an internal standard. Portions of impure product mixture are then exposed to slurries of various stationary phases appropriate for chromatography, in a solvent system suitable as the eluent in flash chromatography. After stirring for 30 min to mimic chromatography, followed by filtering, the samples are analyzed by 1H NMR spectroscopy. Calculated yields for each stationary phase are then compared to that initially obtained from the crude reaction mixture. The results obtained provide a quantitative assessment of the stability of the compound to the different stationary phases; hence the optimal can be selected. The choice of basic alumina, modified to activity IV, as a suitable stationary phase has allowed isolation of certain iodoaziridines in excellent yield and purity.

A protocol for the diastereoselective one-pot preparation of cis-N-Ts-iodoaziridines is described. The generation of diiodomethyllithium, addition to N-Ts aldimines and cyclization of the amino gem-diiodide intermediate to iodoaziridines is demonstrated. Also included is a protocol to rapidly and quantitatively assess the most appropriate stationary phase for purification by chromatography.

합성 및 크로마토 그래피에 대한 최적의 고정상의 양이 선택의 참여 Iodoaziridines의 정화

The highly diastereoselective preparation of cis-N-Ts-iodoaziridines through reaction of diiodomethyllithium with N-Ts aldimines is described. ...

연구

화학

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important structural element found in many complex natural products and pharmaceuticals. Owing to the continual discovery of new guanidine-containing natural products and designed small molecules, rapid and efficient guanidinylation methods are of keen interest to synthetic and medicinal organic chemists. Because the nucleophilicity and basicity of guanidines can affect subsequent chemical transformations, traditional, indirect guanidinylation is typically pursued. Indirect methods commonly employ multiple protection steps involving a latent amine precursor, such as an azide, phthalimide, or carbamate. By circumventing these circuitous methods and employing a direct guanidinylation reaction early in the synthetic sequence, it was possible to forge the linear terminal guanidine containing backbone of clavatadine A to realize a short and streamlined synthesis of this potent factor XIa inhibitor. In practice, guanidine hydrochloride is elaborated with a carefully constructed protecting array that is optimized to survive the synthetic steps to come. In the preparation of clavatadine A, direct guanidinylation of a commercially available diamine eliminated two unnecessary steps from its synthesis. Coupled with the wide variety of known guanidine protecting groups, direct guanidinylation evinces a succinct and efficient practicality inherent to methods that find a home in a synthetic chemist&#39;s toolbox.

Here, we present a protocol for direct, early stage guanidinylation that enables rapid total synthesis of aminoguanidine-containing small organic molecules. An advanced synthetic intermediate used in the synthesis of a blood coagulation factor XIa inhibitor was prepared using this protocol.

복잡한 아미노 구아니딘 함유 천연 제품의 합성에 대한 직접, 초기 단계 Guanidinylation 프로토콜

The guanidine functional group, displayed most prominently in the amino acid arginine, one of the fundamental building blocks of life, is an important ...

Method for Efficient Refolding and Purification of Chemoreceptor Ligand Binding Domain

Identification of natural ligands of chemoreceptors and structural studies aimed at elucidation of the molecular basis of the ligand specificity can be greatly facilitated by the production of milligram amounts of pure, folded ligand binding domains. Attempts to heterologously express periplasmic ligand binding domains of bacterial chemoreceptors in Escherichia coli (E. coli) often result in their targeting into inclusion bodies. Here, a method is presented for protein recovery from inclusion bodies, its refolding and purification, using the periplasmic dCACHE ligand binding domain of Campylobacter jejuni (C. jejuni) chemoreceptor Tlp3 as an example. The approach involves expression of the protein of interest with a cleavable His6-tag, isolation and urea-mediated solubilisation of inclusion bodies, protein refolding by urea depletion, and purification by means of affinity chromatography, followed by tag removal and size-exclusion chromatography. The circular dichroism spectroscopy is used to confirm the folded state of the pure protein. It has been demonstrated that this protocol is generally useful for production of milligram amounts of dCACHE periplasmic ligand binding domains of other bacterial chemoreceptors in a soluble and crystallisable form.

A procedure is presented for the refolding of the dCACHE periplasmic ligand binding domain of Campylobacter jejuni chemoreceptor Tlp3 from inclusion bodies and the purification to yield milligram quantities of protein.

효율적인 Refolding 및 Chemoreceptor Ligand 바인딩 도메인의 정화 방법

Identification of natural ligands of chemoreceptors and structural studies aimed at elucidation of the molecular basis of the ligand specificity can be ...

생화학

The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a sterically demanding ligand, has increased in recent years. The metastable Sn(I) halide is synthesized at&#160;&#34;outer space conditions&#34; via the preparative co-condensation technique. Thereby, the subhalide is synthesized in an oven at high temperatures, around 1,300 &#176;C, and at reduced pressure by the reaction of elemental tin with hydrogen halide gas (e.g., HCl). The subhalide (e.g., SnCl) is trapped within a matrix of an inert solvent, like toluene at -196 &#176;C. Heating the solid matrix to -78 &#176;C gives a metastable solution of the subhalide. The metastable subhalide solution is highly reactive but can be stored at -78 &#176;C for several weeks. On heating the solution to room temperature, a disproportionation reaction occurs, leading to elemental tin and the corresponding dihalide. By applying bulky ligands like Si(SiMe3)3, the intermediate metalloid cluster compounds can be trapped before complete disproportionation to elemental tin. Hence, the reaction of a metastable Sn(I)Cl solution with Li-Si(SiMe3)3 gives [Sn10(Si(SiMe3)3)4]2- 1 as black crystals in high yield. 1 is formed via a complex reaction sequence including salt metathesis, disproportionation, and degradation of larger clusters. Further, 1 can be analyzed by various methods like NMR or single crystal X-ray structure analysis.

The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique

The disproportionation reaction of a metastable Sn(I) chloride solution, obtained via the preparative co-condensation technique, is used for the synthesis of a metalloid tin cluster compound.

합성 [주석<sub&gt; (10)</sub&gt; (시 (SIME<sub&gt; 3</sub&gt;)<sub&gt; 3</sub&gt;)<sub&gt; 4</sub&gt;]<sup&gt; 2</sup<sup&gt; -</sup&gt; 준 안정 주석 (I)을 공 축합 기법을 통해 할라이드의 합성 용액을 사용하여

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a ...

A Dual-Functional Electroactive Filter Towards Simultaneously Sb(III) Oxidation and Sequestration

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon nanotubes. The hybrid titanate-CNT filter was prepared by a sonication coupled with a post-filtration route. Due to the synergistic effects of the increased number of exposed sorption sites, electrochemical reactivity, small pore size of the titanate-CNT network coupled with a flow-through design, simultaneous Sb(III) oxidation and sequestration can be readily achieved. Atomic fluorescence spectrometer technology demonstrated that the applied electrical field accelerates the Sb(III) conversion rate and the as-obtained Sb(V) were adsorbed effectively by the titanate nanowires due to their Sb specificity. This protocol provides a practical solution for the removal of highly toxic Sb(III) and other similar heavy metal ions.

A Dual-Functional Electroactive Filter Towards Simultaneously SbIII Oxidation and Sequestration

A protocol for the rational design of a dual-functional electroactive filter consisting of carbon nanotubes and titanate nanowires is reported and their environmental applications towards Sb(III) oxidation and sequestration is presented.

동시에 Sb (III) 산화 및 격리를 향한 이중 기능 전기 활성 필터

We have designed a facile method to synthesize a dual-functional electrochemical filter consisting of two 1-D materials: titanate nanowires and carbon ...

환경과학

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

We present a method for preparing thioester molecules as the masked form of the thiol linkers and their utilization for accessing a semiconducting and porous metal-dithiolene network in the highly ordered single crystalline state. Unlike the highly reactive free-standing thiols, which tend to decompose and complicate the crystallization of metal-thiolate open frameworks, the thioester reacts in situ to provide the thiol species, serving to mitigate the reaction between the mercaptan units and the metal centers, and to improve crystallization consequently. Specifically, the thioester was synthesized in a one-pot procedure: an aromatic bromide (hexabromotriphenylene) reacted with excess sodium thiomethoxide under vigorous conditions to first form the thioether intermediate product. The thioether was then demethylated by the excess thiomethoxide to provide the thiolate anion that was acylated to form the thioester product. The thioester was conveniently purified by standard column chromatography, and then used directly in the framework synthesis, wherein NaOH and ethylenediamine serve to revert in situ the thioester to the thiol linker for assembling the single-crystalline Pb(II)-dithiolene network. Compared with other methods for thiol synthesis (e.g., by cleaving alkyl thioether using sodium metal and liquid ammonia), the thioester synthesis here uses simple conditions and economical reagents. Moreover, the thioester product is stable and can be conveniently handled and stored. More importantly, in contrast to the generic difficulty in accessing crystalline metal-thiolate open frameworks, we demonstrate that using the thioester for in situ formation of the thiol linker greatly improves the crystallinity of the solid-state product. We intend to encourage broader research efforts on the technologically important metal-sulfur frameworks by disclosing the synthetic protocol for the thioester as well as the crystalline framework solid.

Here, we present a one-pot, transition-metal-free synthesis of thiols and thioesters from aromatic halides and sodium thiomethoxide, followed by the preparation of single crystals of a metal-dithiolene network using thiol species generated in situ from the more stable and tractable thioester.

반도체 Gyroidal 금속-황 프레임 워크의 결정 화에 대 한 Thiol 빌딩 블록의 합성

We present a method for preparing thioester molecules as the masked form of the thiol linkers and their utilization for accessing a semiconducting and ...

Separation of Aldehydes and Reactive Ketones from Mixtures Using a Bisulfite Extraction Protocol

The purification of organic compounds is an essential component of routine synthetic operations. The ability to remove contaminants into an aqueous layer by generating a charged structure provides an opportunity to use extraction as a simple purification technique. By combining the use of a miscible organic solvent with saturated sodium bisulfite, aldehydes and reactive ketones can be successfully transformed into charged bisulfite adducts that can then be separated from other organic components of a mixture by the introduction of an immiscible organic layer. Here, we describe a simple protocol for the removal of aldehydes, including sterically-hindered neopentyl aldehydes and some ketones, from chemical mixtures. Ketones can be separated if they are sterically unhindered cyclic or methyl ketones. For aliphatic aldehydes and ketones, dimethylformamide is used as the miscible solvent to improve removal rates. The bisulfite addition reaction can be reversed by basification of the aqueous layer, allowing for the re-isolation of the reactive carbonyl component of a mixture.

Here, we present a protocol to remove aldehydes and reactive ketones from mixtures by a liquid-liquid extraction protocol directly with saturated sodium bisulfite in a miscible solvent. This combined protocol is rapid and facile to perform. The aldehyde or ketone can be re-isolated by the basification of the aqueous layer.

알 데히드 류와 Ketones 반응 황산 추출 프로토콜을 사용 하 여 혼합물에서 분리

The purification of organic compounds is an essential component of routine synthetic operations. The ability to remove contaminants into an aqueous layer ...

Easy Access to Aliphatic Sulfonamides using Sulfamoyl Chlorides Under Visible Light Activation

Sulfonamides are prevalent motifs in marketed drugs and natural products. Their synthesis represents a great interest to the pharmaceutical industry, due to their unique biological properties. Recently, several methods for the synthesis of aryl sulfonamides have been developed, but little effort has focused on developing one-step methodologies to access sulfonamides flanked by two alkyl groups. This protocol describes a practical and facile method for the net hydrosulfamoylation of electron-deficient alkenes using sulfamoyl chlorides as radical precursors under blue-light activation. This practical and cost-effective methodology is performed in the presence of the metal-free photocatalyst Eosin Y and uses light as a clean and traceless energy source. The procedure is scalable, displays a broad functional group tolerance, and can be applied for late-stage functionalization. All reagents used in this protocol are commercially available. Simple reaction set-up, the absence of work-up and easy purification, demonstrate the convenience of this protocol. The reaction is best applied to electron-deficient alkenes.

Presented here is a protocol for the easy synthesis of aliphatic sulfonamides using sulfamoyl chlorides, (TMS)3SiH and Eosin Y under blue-light irradiation.

Sulfonamides are prevalent motifs in marketed drugs and natural products. Their synthesis represents a great interest to the pharmaceutical industry, due ...

Lipidic Bicelles에서 ABC Transporter Membrane Proteins의 결정화

ABCG5/G8 Crystallization in a Lipidic Bicelle Environment for X-Ray Crystallography

ATP-binding cassette (ABC) transporters constitute lipid-embedded membrane proteins. Extracting these membrane proteins from the lipid bilayer to an aqueous environment is typically achieved by employing detergents. These detergents disintegrate the lipid bilayer and solubilize the proteins. The intrinsic habitat of membrane proteins within the lipid bilayer poses a challenge in maintaining their stability and uniformity in solution for structural characterization. Bicelles, which comprise a blend of long and short-chain phospholipids and detergents, replicate the natural lipid structure. The utilization of lipid bicelles and detergents serves as a suitable model system for obtaining high-quality diffraction crystals, specifically to determine the high-resolution structure of membrane proteins. Through these synthetic microenvironments, membrane proteins preserve their native conformation and functionality, facilitating the formation of three-dimensional crystals. In this approach, the detergent-solubilized heterodimeric ABCG5/G8 was reintegrated into DMPC/CHAPSO bicelles, supplemented with cholesterol. This setup was employed in the vapor diffusion experimental procedure for protein crystallization.

저자 스포트라이트: 약물 개발을 촉진하기 위한 ABC 수송체 막 단백질의 이중세포 결정화 설정 

This protocol describes a setup for the crystallization of the sterol transporter ABCG5/G8. ABCG5/G8 is reconstituted into bicelles for hanging-drop crystallization. The protocol does not require specialized materials or substrates, making it accessible and easy to adapt in any laboratory for determining the protein structure through X-ray crystallography.

X선 결정학을 위한 지질 이중세포 환경에서의 ABCG5/G8 결정화

ATP-binding cassette (ABC) transporters constitute lipid-embedded membrane proteins. Extracting these membrane proteins from the lipid bilayer to an ...

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X선 결정학을 위한 지질 이중세포 환경에서의 ABCG5/G8 결정화

X선 결정학을 위한 지질 이중세포 환경에서의 ABCG5/G8 결정화