Foil-Forged Images X 射线衍射广泛用于确定分子几何形状,通常可以区分镜像异构体(对映异构体),这通常需要有序的晶体。赫维格等人。(p. 1084) 报告了一种表征气相对映异构体的成像技术。通过碳箔引发一系列电离事件,最终导致相互排斥的原子核发生库仑爆炸。这些原子核的轨迹准确地反映了原始的分子结构。当原子核飞散时,碳箔的超快电子剥离能够精确阐明分子几何形状。在化学和生物学中,手性或手性是指存在于两个空间配置中的分子,它们是彼此不一致的镜像。几乎所有的生物活性分子都是手性的,正确确定它们的绝对构型对于理解和发展涉及手性分子的过程至关重要。异常 X 射线衍射和振动光学活动测量被广泛用于确定固体或液体样品的绝对构型。确定气相中手性分子的绝对构型仍然是一项艰巨的挑战。在这里,我们展示了通过单个分子的箔诱导库仑爆炸成像来确定同位素标记的 (R,R)-2,3-双氘环氧乙烷的绝对构型。
The absoluteconfiguration of (R,R)‐2,3‐dideuterooxirane, which has been independently determined using Coulombexplosionimaging, has been unambiguously chemically correlated with the stereochemical key reference (+)‐glyceraldehyde. This puts the absoluteconfiguration of D(+)‐glyceraldehyde on firm experimental grounds.
(R,R)- and (S,S)-[1,2-2H2]oxiranes have been synthesized from prop-2-yn-1-ol, the key step being asymmetric epoxidation of (E)-3-(triphenylsilyl)[2,3-2H2]prop-2-en-1-ol.
(R,R)-和(S,S)-[1,2- 2 H 2 ]氧杂环戊烷是由prop-2-yn-1-ol合成的,关键步骤是(E)-3-的不对称环氧化(三苯基甲硅烷基)[2,3- 2 H 2 ] prop-2-en-1-ol。
The steric course of the reaction of ethylene oxide with hydrogen halides in the gas phase
The stericcourse of the gas-phase reaction of trans-[2H2]ethyleneoxide with HF, HCl, and HBr was investigated in order to test experimentally a mechanistic proposal based on ab initio calculations involving a concerted syn-opening mechanism. In contrast with this proposal the reactions with HCl and HBr take place entirely with anti-opening of the ring to give erythro-2-chloro- and 2-bromo[1,2-2H2]ethanol
samples. Determining absoluteconfigurations of chiral molecules in the gas phase is still a formidable challenge. Here we demonstrate the determination of the absoluteconfiguration of isotopically labeled (R,R)-2,3-dideuterooxirane by foil-induced Coulombexplosionimaging of individual molecules. Our technique provides unambiguous and direct access to the absoluteconfiguration of small gas-phase
Foil-Forged Images X 射线衍射广泛用于确定分子几何形状,通常可以区分镜像异构体(对映异构体),这通常需要有序的晶体。赫维格等人。(p. 1084) 报告了一种表征气相对映异构体的成像技术。通过碳箔引发一系列电离事件,最终导致相互排斥的原子核发生库仑爆炸。这些原子核的轨迹准确地反映了原始的分子结构。当原子核飞散时,碳箔的超快电子剥离能够精确阐明分子几何形状。在化学和生物学中,手性或手性是指存在于两个空间配置中的分子,它们是彼此不一致的镜像。几乎所有的生物活性分子都是手性的,正确确定它们的绝对构型对于理解和发展涉及手性分子的过程至关重要。异常 X 射线衍射和振动光学活动测量被广泛用于确定固体或液体样品的绝对构型。确定气相中手性分子的绝对构型仍然是一项艰巨的挑战。在这里,我们展示了通过单个分子的箔诱导库仑爆炸成像来确定同位素标记的 (R,R)-2,3-双氘环氧乙烷的绝对构型。
Synthesis of (2R,3R)- and (2S,3S)-[2,3-2H2]oxirane and application of it to the synthesis of chirally labeled homoserine