The authors thank the Natural Sciences and Engineering Research Council (NSERC) of Canada and the Canada Foundation for Innovation (CFI) for funding and scholarship support.

주 : 중수소 용매가 필요하고, 다른 모든 용매 Grubbs&#39; 형 컬럼 (12)의 연속상에서 건조시키고 사용 전에 탈기 때 문헌 과정에 따라 건조시켰다. 칼륨 1,2,4- 트리스 (디 페닐 포스 피노) 사이클로 펜타 [K] (PH 2 P) 3 C (5) H 2] 및 N 헤테로 카르 벤 -1,3,4,5- tetramethylimidazole -2- 일리 덴 (ME NHC 째 )은 문헌의 절차에 따라 합성하고, 후자는 사용 전에 승화시켰다. 9, 13의 시클로 헥센은 CAH이 건조 증류 제거하고 사용하기 전에 탈기시켰다. 아세토 니트릴 3-D (CD 3 CN) 및 디클로로 메탄 (D2) (CD 2 CL 2) 오산화 인상에서 건조시키고, 사용 전에 탈기시켰다. 규조토는 사용하기 전에 150 ºC 밤새 오븐에서 건조시켰다. 수신 된 모든 다른 시약을 사용 하였다. [dppeP] 1. 합성 어 [br] <ol><li> 디무수 약 40 ㎖ 중의 1,2- 비스 (디 페닐 포스 피노) 에탄 (dppe)의 issolve 1.00 g는 고무 격막이 장착 불활성 가스 하에서, 250 mL 쉴 렝크 (schlenk) 플라스크에 디클로로 메탄 (DCM)을 탈기. </li><li> 주사기 나 캐 뉼러를 전송함으로써, dppe의 교반 용액을 포함하는 쉬 렌크 플라스크에 건조, 탈기, 사이클로 헥센의 2.53 ml를 추가합니다. </li><li> 이 용액에, 주사기를 통해 PBR 3 0.26를 가하여 격렬하게 교반하면서 적가 하였다. 용액은 즉시 20 분 동안 용액을 교반 한 후 옅은 황색, 백색 침전물이 형성됨을 설정한다. 반응이 몇 시간 또는 하룻밤 동안 교반 할 수 있습니다. </li><li> 프릿 플라스크 침전물을 제거하기 위해 1 인치 두께의 규조토 플러그 얹어 통해 몇 시간 동안 교반 또는 하룻밤 후, 반응 혼합물을 필터. </li><li> 생성 된 용액을 수집하고 쉬 렌크 라인에 진공하에 DCM을 제거합니다. </li><li> 얻어진 오일을 테트라 하이드로 퓨란 중 약 75 ㎖ (THF)을 첨가하는 동안 성격렬 irring (또는 초음파 처리)을 백색 고체로서 생성물을 침전시킨다. </li><li> 즉시 백색 침전물을 형성 한 후, 불활성 분위기 하에서 프릿 플라스크에 여과를 통해 수집합니다. 즉시 고체를 수집하고, 30 분 동안 교반 현탁액을 두지 마십시오. </li><li> 일단 수집 순도를 확인하기 위해 31 P, 1 H, 13 C NMR을 얻기 위해 CD이 CL 2 CDCl3 중의 [브롬] dppeP] 소량 녹인다. [dppeP] [브롬]는 불활성 분위기에서 무기한 저장, 또는 벤치 탑에 몇 주 동안 할 수있다. (6) </li></ol> [dppeP] 2. 합성 BPH 4] <ol><li> 쉬 렌크 플라스크에, DCM 5ml에 [dppeP] [브롬] 염 0.5 g을 녹여. 질소 하에서이 용액을 교반 하였다. 이어서, THF 5 ml의 테트라 페닐 보레이트 나트륨 0.35 g을 추가한다. </li><li> 이 솔루션은 미세한 침전물이 형성 될 때까지, 밤새 몇 시간 동안 교반 할 수 있습니다. </li><li> 의 S를 원심 분리기uspension 침전물 (KBr을)를 제거하고 [dppeP] BPH 4] 백색 분말로서 수득 감압하에 용매를 제거한다. </li></ol> 3. 합성 [나 NHC 나 2 P] [BPH 4] <ol><li> 0.200 나 NHC의 g 나와 불활성 분위기 하에서 교반 막대와 100 ㎖ 쉬 렌크 플라스크를 넣습니다. </li><li> 불활성 분위기 하에서 [dppeP] [BPH 4]의 0.603 g을 100 ml의 둥근 바닥 플라스크를 넣습니다. </li><li> 나의 0.200 g NHC 나와 시작 자석 교반을 포함하는 쉬 렌크 플라스크에 THF의 정맥 전송 20 ㎖. </li><li> 정맥 전송은 20 dppeP] [BPH 4]의 0.603 g과 100 ㎖ 둥근 바닥 플라스크에 THF ml의 용해 될 때까지 교반한다. </li><li> 정맥은 [dppeP] [BPH 4] THF의 THF에 나 NHC 날의 교반 솔루션의 솔루션을 전송하고 황색 용액을 1 시간 동안 교반 할 수 있습니다. </li><li> 노란색의 농축감압하에 원래 부피 (13 mL)을 1/3 olution. </li><li> 황색 생성물의 침전을 개시하고 생성 된 현탁액을 20 분 동안 교반하도록 교반 농축 용액에 디 에틸 에테르 (ET 2 O) (40 ml)에 추가한다. </li><li> 쉬 렌크 라인에 100 ㎖ 쉬 렌크 플라스크에 부착 장착 된 밀봉 프릿을 놓고 플라스크를 배기 진공을 사용하고 슐렉 라인에서 질소로 플라스크를 리필하여 불활성 분위기를 만들 수 있습니다. 5 분 동안 피난 불활성 분위기를 보장하기 위해, 질소로 3 회 재충전. </li><li> 캐 뉼러 장치에 잇 2 O 현탁액을 전송하고, 침전물을 필터링. </li><li> 잇 2 O 3 회 10 ml의 침전물을 세척하고 침전물이 2 시간 동안 감압하에 건조 할 수 있습니다. </li><li> ) 옵션은 여과 및 세척이 dppe을 재결정 질소 하에서 천천히 증발하도록 허용합니다. 헥산 건조 최소량으로 결정을 세척하고, 수집재사용 결정. </li></ol> (박사 2 P) C 5 H 2 (박사 2 P) (2) (4) 합성 P <ol><li> 불활성 분위기에서 150 ㎖의 쉬 렌크 플라스크에 포함 0.484g [dppeP] [브롬]로, 건조 40ml를 추가, THF를 탈기. </li><li> -78 ℃로 현탁액의 온도를 드라이 아이스 / 아세톤 조에서 슈렌 배치. </li><li> 정맥은 0.625g의 THF 용액을 전송 [K] [(박사 2 P) 3 C 5 H 2] 둥근 바닥 플라스크에, [dppeP]가 포함 된 쉬 렌크 플래시에 어 [br]. </li><li> 첨가가 완료되면, 아세톤 조에서 쉴 렌크 플라스크를 제거하고 실온으로 가온 할 수있다. 2 시간 동안 교반 한 후, 용액을 백색 침전물 선물을 담황색 것이다. </li><li> 흰색 침전물 (KBr을)를 제거하기 위해, 150 ml의 쉬 렌크 플라스크가 장착 된 공기가없는 융해 필터에 정지를 전송합니다. </li><li> 노란색 솔루션을 수집하고 진공하에 THF를 제거합니다. </li><li> 80:20 추가건조 탈기 된 디 에틸 에테르의 혼합물 : 얻어진 오일 펜탄, 20 분 동안 교반한다. </li><li> 제품을 수집 (박사 2 P) C 5 H 2 (박사 2 P)이 P 공기 무료, 프릿 플라스크를 통해 정지를 필터링하여 옅은 노란색 침전물있다. 나머지 에테르 / 펜탄 용액 dppe 불순물을 포함하고 폐기 될 수 있거나 또는 용매를 진공 또한 사용 수집 dppe하에 제거 될 수있다. </li></ol>

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저자는 공개 아무것도 없어.

결정 구조 및 멀티 NMR은 핵 (31 P, 1 H, 13 C) 연결성을 확인하기 위해보고 된 모든 제품을 얻었다. 전기 분무 이온화 질량 분석법은 양이온의 존재를 확인하는 데 사용하고, 원소 분석은 샘플의 분석 순도를 확인 하였다. 모든 반응 또는 분해시 생성되는 부산물 전혀 예상치 못한이 형성되지 않도록 공기가없는 건조한 환경에서 수행하는 것이 필수적이다...

비정상적으로 낮은 산화 또는 원자가 상태에서 전형 원소의 화학은 지난 20 년 동안 상당한 관심의 영역이었다. 일을 제외하고 독특한 결합과 구조에서 발생하는 근본적인 관심에서, 이러한 화합물은 종종 매우 다른 반응성을 표시 그들의 전형적인 산화 상태의 대응들. 이러한 의미에서, 이들은보다 복잡한 주족 원소 함유 물질을 구축하는 시약으로서 상당한 잠재력을 제공한다. 분자를 포함하는 저 가의 인의 랜드 마크 클래스는 먼저 1980 년대에 Schmidpeter에 의해보고되었다 &quot;triphosphenium&quot;양이온이다. 2보다 안정적인 변종이에서 내장 된 이들 이온은,이 phosphonio 치환기에 의해 결찰 dicoordinate의 인 (I) 이온 기능 . 킬레이트 프레임 워크 3,4 우리 그룹은 triphosphenium 할라이드 염의 합성 최적화 5있다 - 7가이러한 안정한 화합물 다용도 P의 + 전송 인 (I)의 제어 된 합성을위한 유용한 제제 함유 올리고머 8 양쪽 성 이온, 9 phosphamethine 시아닌 염료 있음. 10,11 이러한 화합물의 원래의 합성은 종종 위험한 인을 포함하지만 입증 시약을 함유 및 / 또는 높은 환원 조건, 우리가 제시 제어 경로는 안전, P 원자 효율적이고 편리하다. 염료로서 사용될 수있다 고순도 재료에있어서의 결과는, 전이 금속 착물과 더 복잡한 인 함유 종 전구체 리간드.

<table border="0" cellpadding="0" cellspacing="0" width="968">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">bis(diphenyl)phosphino ethane (dppe)</td>
			<td style="width:99px;">Strem</td>
			<td style="width:119px;">1663-45-2</td>
			<td style="width:468px;">98% Stored in gloved box, used as is.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Anhydrous Dichloromethane (DCM)</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">270997</td>
			<td>Purified through solvent purification system, or standard methods</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Anhydrous Cyclohexene&#160;</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">29240</td>
			<td>Dried over calcium hydride and distilled.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Phosphorus Tribromide (PBr3)</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">157783</td>
			<td>99% Stored in glove box, used as is. Air sensitive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Anyhydrous Tetrahydrofuran (THF)</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">401757</td>
			<td>Purified through solvent purification system, or standard methods</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Methylene Chloride-D2 (CD2Cl2)</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td style="width:119px;">DLM-23-25</td>
			<td>Dried over phosphorus pentoxide, vacuum transferred or distilled</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Acetonitrile</td>
			<td style="width:99px;">Alfa Aesar</td>
			<td align="right" style="width:119px;">5/8/1975</td>
			<td>Stored in glove box, used as is</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Sodium Tetraphenylborate</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td style="width:119px;">T25402</td>
			<td>Stored in glove box, used as is</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Anyhydrous Diethyl Ether&#160;</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">673811</td>
			<td>Purified through solvent purification system, or standard methods</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:283px;">Anhydrous Pentane</td>
			<td style="width:99px;">Sigma Aldrich</td>
			<td align="right" style="width:119px;">236705</td>
			<td>Purified through solvent purification system, or standard methods</td>
		</tr>
	</tbody>
</table>

preparation and reactivity of a triphosphenium bromide salt: a convenient and stable source of phosphorus(i)

우리는 본원 triphosphenium 브로마이드 염 최적화 합성을 제시한다. 그렇다 다목적 복분해되는 시약이 비정상적으로 낮은 안정 가의 - 인 - 함유 화합물의 유용한 P + 이동제로서 작용한다. 전통적인 방법에 액세스하기 위해 사용될 달리 인 보통 자연 발화성 인 - 함유 전구체 (백색 인, 트리스 (트리메틸 실릴) 포스 핀 등), 또는 강한 환원제 (알칼리 금속 칼륨, 흑연 등)을 필요로 종 전류를 둘러 좌표 접근 방식은 자연 발화성 또는 폭발성 시약을 포함하지 않는 기본적인 공기가없는 합성 교육 학부에 의해 우수한 수익률에 큰 규모 (&gt; 20g)을 수행 할 수 있습니다. 브롬 대 이온 용이 원하는 특성 및 반응성을 가진 물질을 얻기 위해 일반적인 염 복분해 시약을 이용한 (이하 설명) 페닐 붕산과 같은 다른 음이온으로 교환된다. 이 P +의 전달 (A)의 다 기능성pproach 용이 각각 양성 이온을 함유하는 NHC 안정화 인 (I) 양이온 인 (I)을 수득 중립 스포 스핀 변위 각의 N 헤테로 카르 벤 및 음이온 스포 스핀, 이러한 triphosphenium 전구체의 반응에 의해 예시 .

저 가의 인 (I)의 소스를 함유하는 안정한 염 ([dppeP] 브롬]) 과량의 시클로 헥센의 존재 diphenylphosphinoethane (dppe)에 PBR 3의 첨가에 의해 용이하게 (도 1)를 합성 할 수있다 (6). 반응의 워크 업 후, 31 P NMR 스펙트럼은 상당히 -220 ppm으로 차폐 삼중 신호의 존재는 50 ppm에서 이중선 신호를 나타낸다. 핵 사이의 강한 결합은 5...

Watch this Scientific Journal Video about Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI at JoVE.com

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI

The synthesis of a triphosphenium bromide salt is described and its use as a P+ transfer agent is outlined by reactions with an N-heterocyclic carbene and an anionic bisphosphine, yielding an NHC-stabilized P(I) cation and a P(I) containing zwitterion, respectively.

Triphosphenium 브로마이드 소금의 제조 및 반응성 : 인의 편리하고 안정적인 소스 (I)

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable ...

preparation-reactivity-triphosphenium-bromide-salt-convenient-stable

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JoVE Journal

Chemistry

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)

7.7K 조회수.  University of Windsor. The synthesis of a triphosphenium bromide salt is described and its use as a P+ transfer agent is outlined by reactions with an N-heterocyclic carbene and an anionic bisphosphine, yielding an NHC-stabilized P(I) cation and a P(I) containing zwitterion, respectively.

비디오: Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI

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

Although initially considered an esoteric reagent, SmI2 has become a common tool for synthetic organic chemists. SmI2 is generated through the addition of molecular iodine to samarium metal in THF.1,2-3 It is a mild and selective single electron reductant and its versatility is a result of its ability to initiate a wide range of reductions including C-C bond-forming and cascade or sequential reactions. SmI2 can reduce a variety of functional groups including sulfoxides and sulfones, phosphine oxides, epoxides, alkyl and aryl halides, carbonyls, and conjugated double bonds.2-12 One of the fascinating features of SmI-2-mediated reactions is the ability to manipulate the outcome of reactions through the selective use of cosolvents or additives. In most instances, additives are essential in controlling the rate of reduction and the chemo- or stereoselectivity of reactions.13-14 Additives commonly utilized to fine tune the reactivity of SmI2 can be classified into three major groups: (1) Lewis bases (HMPA, other electron-donor ligands, chelating ethers, etc.), (2) proton sources (alcohols, water etc.), and (3) inorganic additives (Ni(acac)2, FeCl3, etc).3
Understanding the mechanism of SmI2 reactions and the role of the additives enables utilization of the full potential of the reagent in organic synthesis. The Sm-Barbier reaction is chosen to illustrate the synthetic importance and mechanistic role of two common additives: HMPA and Ni(II) in this reaction. The Sm-Barbier reaction is similar to the traditional Grignard reaction with the only difference being that the alkyl halide, carbonyl, and Sm reductant are mixed simultaneously in one pot.1,15 Examples of Sm-mediated Barbier reactions with a range of coupling partners have been reported,1,3,7,10,12 and have been utilized in key steps of the synthesis of large natural products.16,17 Previous studies on the effect of additives on SmI2 reactions have shown that HMPA enhances the reduction potential of SmI2 by coordinating to the samarium metal center, producing a more powerful,13-14,18 sterically encumbered reductant19-21 and in some cases playing an integral role in post electron-transfer steps facilitating subsequent bond-forming events.22 In the Sm-Barbier reaction, HMPA has been shown to additionally activate the alkyl halide by forming a complex in a pre-equilibrium step.23
Ni(II) salts are a catalytic additive used frequently in Sm-mediated transformations.24-27 Though critical for success, the mechanistic role of Ni(II) was not known in these reactions. Recently it has been shown that SmI2 reduces Ni(II) to Ni(0), and the reaction is then carried out through organometallic Ni(0) chemistry.28
These mechanistic studies highlight that although the same Barbier product is obtained, the use of different additives in the SmI2 reaction drastically alters the mechanistic pathway of the reaction. The protocol for running these SmI2-initiated reactions is described.

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

A straightforward procedure for the preparation of samarium diiodide (SmI2) in THF is described. The role of two main additives namely hexamethylphosphoramide (HMPA) and Ni(acac)2 in Sm mediated reactions is demonstrated in the Sm-Barbier reaction.

준비와 사마륨 Diiodide 이용 (SMI<sub&gt; 2</sub&gt;) 유기 합성의 : 사마륨 Barbier 반응에 HMPA과 니켈 (II) 소금의 기계론의 역할

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

연구

화학

Preparing Adherent Cells for X-ray Fluorescence Imaging by Chemical Fixation

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over large or small sample areas. It has been applied in many areas of science, including materials science, geoscience, studying works of cultural heritage, and in chemical biology. In the case of chemical biology, for example, visualizing the metal distributions within cells allows us to study both naturally-occurring metal ions in the cells, as well as exogenously-introduced metals such as drugs and nanoparticles. Due to the fully hydrated nature of nearly all biological samples, cryo-fixation followed by imaging under cryogenic temperature represents the ideal imaging modality currently available. However, under the circumstances that such a combination is not easily accessible or practical, aldehyde based chemical fixation remains useful and sometimes inevitable. This article describes in as much detail as possible in the preparation of adherent mammalian cells by chemical fixation for X-ray fluorescent imaging.

Here, we present a protocol on how to determine the quantity and distribution of metals in a sample using synchrotron X-ray fluorescence. We focus on adherent cells, and describe the chemical fixation method to prepare this sample. We then describe how to mount and image the sample using synchrotron X-rays.

화학 고정하여 X-ray 형광 이미징 부착 세포를 준비

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over ...

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Herein we report the synthesis of a tridentate phosphine ligand N(CH2PPh2)3 (N-triphosPh) (1) via a phosphorus based Mannich reaction of the hydroxylmethylene phosphine precursor with ammonia in methanol under a nitrogen atmosphere. The N-triphosPh ligand precipitates from the solution after approximately 1 hr of reflux and can be isolated analytically pure via simple cannula filtration procedure under nitrogen. Reaction of the N-triphosPh ligand with [Ru3(CO)12] under reflux affords a deep red solution that show evolution of CO gas on ligand complexation. Orange crystals of the complex [Ru(CO)2{N(CH2PPh2)3}-&#954;3P] (2) were isolated on cooling to RT. The 31P{1H} NMR spectrum showed a characteristic single peak at lower frequency compared to the free ligand. Reaction of a toluene solution of complex 2 with oxygen resulted in the instantaneous precipitation of the carbonate complex [Ru(CO3)(CO){N(CH2PPh2)3}-&#954;3P] (3) as an air stable orange solid. Subsequent hydrogenation of 3 under 15 bar of hydrogen in a high-pressure reactor gave the dihydride complex [RuH2(CO){N(CH2PPh2)3}-&#954;3P] (4), which was fully characterized by X-ray crystallography and NMR spectroscopy. Complexes 3 and 4 are potentially useful catalyst precursors for a range of hydrogenation reactions, including biomass-derived products such as levulinic acid (LA). Complex 4 was found to cleanly react with LA in the presence of the proton source additive NH4PF6 to give [Ru(CO){N(CH2PPh2)3}-&#954;3P{CH3CO(CH2)2CO2H}-&#954;2O](PF6) (6).

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes

Ruthenium phosphine complexes are widely used for homogeneous catalytic reactions such as hydrogenations. The synthesis of a series of novel tridentate ruthenium complexes bearing the N-triphos ligand N(CH2PPh2)3 is reported. Additionally, the stoichiometric reaction of a dihydride Ru&#8211;N-triphos complex with levulinic acid is described.

루테늄의 시리즈의 합성, 특성 및 반응성<em&gt; N</em&gt; -triphos<sup&gt; 박사</sup&gt; 단지

Herein we report the synthesis of a tridentate phosphine ligand N(CH2PPh2)3 (N-triphosPh) (1) via a phosphorus based Mannich reaction of the ...

Preparation of Mica and Silicon Substrates for DNA Origami Analysis and Experimentation

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of these applications require interaction with and adhesion of DNA nanostructures to a substrate. Due to its atomically flat and easily cleaned nature, mica has been the substrate of choice for DNA origami experiments. However, the practical applications of mica are relatively limited compared to those of semiconductor substrates. For this reason, a straightforward, stable, and repeatable process for DNA origami adhesion on derivatized silicon oxide is presented here. To promote the adhesion of DNA nanostructures to silicon oxide surface, a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) is deposited from an aqueous solution that is compatible with many photoresists. The substrate must be cleaned of all organic and metal contaminants using Radio Corporation of America (RCA) cleaning processes and the native oxide layer must be etched to ensure a flat, functionalizable surface. Cleanrooms are equipped with facilities for silicon cleaning, however many components of DNA origami buffers and solutions are often not allowed in them due to contamination concerns. This manuscript describes the set-up and protocol for in-lab, small-scale silicon cleaning for researchers who do not have access to a cleanroom or would like to incorporate processes that could cause contamination of a cleanroom CMOS clean bench. Additionally, variables for regulating coverage are discussed and how to recognize and avoid common sample preparation problems is described.

Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.

DNA 종이 접기 분석 및 실험에 대한 운모와 실리콘 기판의 제조

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of ...

Preparation and Characterization of Individual and Multi-drug Loaded Physically Entrapped Polymeric Micelles

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar concentration forming hydrophobic cores surrounded by hydrophilic shells in aqueous environments. The core of these micelles can be utilized to load hydrophobic, poorly water soluble drugs like docetaxel (DTX) and everolimus (EVR). Systematic characterization of the micelle structure and drug loading capabilities are important before in vitro and in vivo studies can be conducted. The goal of the protocol described herein is to provide the necessary characterization steps to achieve standardized micellar products. DTX and EVR have intrinsic solubilities of 1.9 and 9.6 &#181;g/ml respectively Preparation of these micelles can be achieved through solvent casting which increases the aqueous solubility of DTX and EVR to 1.86 and 1.85 mg/ml, respectively. Drug stability in micelles evaluated at room temperature over 48 hr indicates that 97% or more of the drugs are retained in solution. Micelle size was assessed using dynamic light scattering and indicated that the size of these micelles was below 50 nm and depended on the molecular weight of the polymer. Drug release from the micelles was assessed using dialysis under sink conditions at pH 7.4 at 37 oC over 48 hr. Curve fitting results indicate that drug release is driven by a first order process indicating that it is diffusion driven.

The goal of this protocol is to describe the preparation and characterization of physically entrapped, poorly water soluble drugs in micellar drug delivery systems composed of amphiphilic block copolymers.

준비 및 개인의 특성과 다중 약물은 물리적으로 고분자 미셀을 포획로드

Amphiphilic block copolymers like polyethyleneglycol-block-polylactic acid (PEG-b-PLA) can self-assemble into micelles above their critical micellar ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

주변 조건에 따라 금 나노 입자의 안정 올리고머 클러스터의 크기 제어 합성을위한 간단한 방법

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of Chalcogenidoplumbates(II or IV)

The phases of &#34;PbCh2&#34; (Ch = Se, Te) are obtained from solid-state syntheses (i.e., by the fusion of the elements under inert conditions in silica glass ampules). Reduction of such phases by elemental alkaline metals in amines affords crystalline chalcogenidoplumbate(II) salts comprised of [PbTe3]2- or [Pb2Ch3]2- anions, depending upon which sequestering agent for the cations is present: crown ethers, like 18-crown-6, or cryptands, like [2.2.2]crypt. Reactions of solutions of such anions with transition-metal compounds yield (poly-)chalcogenide anions or transition-metal chalcogenide clusters, including one with a &#181;-PbSe ligand (i.e., the heaviest-known CO homolog).
In contrast, the solid-state synthesis of a phase of the nominal composition &#34;K2PbSe2&#34; by successive reactions of the elements and by the subsequent solvothermal treatment in amines yields the first non-oxide/halide inorganic lead(IV) compound: a salt of the ortho-selenidoplumbate(IV) anion [PbSe4]4-. This was unexpected due to the redox potentials of Pb(IV) and Se(-II). Such methods can further be applied to other elemental combinations, leading to the formation of solutions with binary [HgTe2]2- or [BiSe3]3- anions, or to large-scale syntheses of K2Hg2Se3 or K3BiSe3 via the solid-state route.
All compounds are characterized by single-crystal X-ray diffraction and elemental analysis; solutions of plumbate salts can be investigated by 205Pb and 77Se or 127Te NMR techniques. Quantum chemical calculations using density functional theory methods enable energy comparisons. They further allow for insights into the electronic configuration and thus, the bonding situation. Molecular Rh-containing Chevrel-type compounds were found to exhibit delocalized mixed valence, whereas similar telluridopalladate anions are electron-precise; the cluster with the &#181;-PbSe ligand is energetically favored over a hypothetical CO analog, in line with the unsuccessful attempt at its synthesis. The stability of formal Pb(IV) within the [PbSe4]4- anion is mainly due to a suitable stabilization within the crystal lattice.

Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV

The synthesis of chalcogenidoplumbates(II,IV) via the in situ reduction of nominal "PbCh2" (Ch = Chalcogen) and via a solid-state reaction and subsequent solvothermal reactions is presented. Additionally, reactivities of plumbate(II) solutions are portrayed, which yield the heaviest-known CO homolog known to date: the &#181;-PbSe ligand.

고체 및 솔루션 기반의 기술 결합 : 합성 및 Chalcogenidoplumbates의 반응성 (II 또는 IV)

The phases of &#34;PbCh2&#34; (Ch = Se, Te) are obtained from solid-state syntheses (i.e., by the fusion of the elements under inert conditions in silica ...

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the inverse electron demand Diels-Alder (IEDDA) cycloaddition between a radiolabeled tetrazines and trans-cyclooctene (TCO) linked to a biomolecule has proven to be a highly effective bioorthogonal approach to imaging specific biological targets. Despite the fact that technetium-99m remains the most widely used isotope in diagnostic nuclear medicine, there is a scarcity of methods for preparing 99mTc-labeled tetrazines. Herein we report the preparation of a family of tridentate-chelate-tetrazine derivatives and their Tc(I) complexes. These hitherto unknown compounds were radiolabeled with 99mTc using a microwave-assisted method in 31% to 83% radiochemical yield. The products are stable in saline and PBS and react rapidly with TCO derivatives in vitro. Their in vivo pre-targeting abilities were demonstrated using a TCO-bisphosphonate (TCO-BP) derivative that localizes to regions of active bone metabolism or injury. In murine studies, the 99mTc-tetrazines showed high activity concentrations in knees and shoulder joints, which was not observed when experiments were performed in the absence of TCO-BP. The overall uptake in non-target organs and pharmacokinetics varied greatly depending on the nature of the linker and polarity of the chelate.

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Here, we describe a protocol for radiolabeling and in vivo testing of tridentate 99mTc(I) chelate-tetrazine derivatives for pre-targeting and bioorthogonal chemistry.

준비 및 평가<sup&gt; 99m</sup&gt; Bioorthogonal 화학을 사용하여 사전이 타겟팅에 대한 세자리 킬레이트를 Tc를 표지

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the ...

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and related diseases, but their precise measurement is still a challenge. Many protocols have been described for neurotransmitter measurement by a variety of instruments, including high-pressure liquid chromatography (HPLC). However, there are shortcomings, such as complicated operation or hard-to-detect multiple targets, which cannot be avoided, and presently, the dominant analysis technique is still HPLC coupled with sensitive electrochemical or fluorimetric detection, due to its high sensitivity and good selectivity. Here, a detailed protocol is described for the pretreatment and detection of catecholamines with high pressure liquid chromatography with electrochemical detection (HPLC-ECD) in real urine samples of infants, using electrospun composite nanofibers composed of polymeric crown ether with polystyrene as adsorbent, also known as the packed-fiber solid phase extraction (PFSPE) method. We show how urine samples can be easily precleaned by a nanofiber-packed solid phase column, and how the analytes in the sample can be rapidly enriched, desorbed, and detected on an ECD system. PFSPE greatly simplifies the pretreatment procedures for biological samples, allowing for decreased time, expense, and reduction of the loss of targets. 
Overall, this work illustrates a simple and convenient protocol for solid-phase extraction coupled to an HPLC-ECD system for simultaneous determination of three monoamine neurotransmitters (norepinephrine (NE), epinephrine (E), dopamine (DA)) and two of their metabolites (3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxy-phenylacetic acid (DOPAC)) in infants' urine. The established protocol was applied to assess the differences of urinary catecholamines and their metabolites between high-risk infants with perinatal brain damage and healthy controls. Comparative analysis revealed a significant difference in urinary MHPG between the two groups, indicating that the catecholamine metabolites may be an important candidate marker for early diagnosis of cases at risk for brain damage in infants.

We present a convenient solid-phase extraction coupled to high-pressure liquid chromatography (HPLC) with electrochemical detection (ECD) for simultaneous determination of three monoamine neurotransmitters and two of their metabolites in infants' urine. We also identify the metabolite MHPG as a potential biomarker for the early diagnosis of brain damage for infants.

추출 및 카 테 콜 아민 신경 전달 물질과 그들의 대사 산물의 고압 액체 크로마토그래피로 분석 하는 편리한 방법

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and ...

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Bicyclic aziridinium ions were generated by the removal of an appropriate leaving group through internal nucleophilic attack by nitrogen atom in the aziridine ring. The utility of bicyclic aziridinium ions, specifically 1-azoniabicyclo[3.1.0]hexane and 1-azoniabicyclo[4.1.0]heptane tosylate highlighted in the aziridine ring openings by the nucleophile with the release of the ring strain to yield the corresponding ring-expanded azaheterocycles such as pyrrolidine, piperidine and azepane with diverse substituents on the ring in regio- and stereospecific manner. Herein, we report a simple and convenient method for the preparation of the stable 1-azabicyclo[4.1.0]heptane tosylate followed by selective ring opening via a nucleophilic attack either at the bridge or at the bridgehead carbon to yield piperidine and azepane rings, respectively. This synthetic strategy allowed us to prepare biologically active natural products containing piperidine and azepane motif including sedamine, allosedamine, fagomine and balanol in highly efficient manner.

Bicyclic aziridinium ions such as 1-azoniabicyclo[4.1.0]heptane tosylate were generated from 2-[4-tolenesulfonyloxybutyl]aziridine, which was utilized for the preparation of substituted piperidines and azepanes via regio- and stereospecific ring-expansion with various nucleophiles. This highly efficient protocol allowed us to prepare diverse azaheterocycles including natural products such as fagomine, febrifugine analogue and balanol.

Azaheterocycles의 합성에 대 한 안정적인 Bicyclic Aziridinium 이온과 그들의 반지 개통 준비

Bicyclic aziridinium ions were generated by the removal of an appropriate leaving group through internal nucleophilic attack by nitrogen atom in the ...

Triphosphenium 브로마이드 소금의 제조 및 반응성 : 인의 편리하고 안정적인 소스 (I)

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준비와 사마륨 Diiodide 이용 (SMI