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Updated: Jul 18, 2025

Coulomb Explosion Imaging as a Tool to Distinguish Between Stereoisomers
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基于后效应的44m/44g核异构体的分离

Elena Sergeevna Kurakina1,2, Luke Wharton3, Jurabek Khushvaktov1

  • 1Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna 141980, Russian Federation.

Inorganic chemistry
|August 25, 2023
PubMed
概括

扫-44 (44gSc) 非常适合用于PET成像. 研究人员开发了一种用于44gSc生产的新型发电机,利用后效应在核医学应用中提高产量.

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A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
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Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
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Mass Spectrometry: Isotope Effect

Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the difference between the molecular mass. Furthermore, the intensity of these signals is dependent on the...
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In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
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