Determination of long-range scalar H-1-H-1 coupling constants responsible for polarization transfer in SABRE
| Autor: | Bram J. A. van Weerdenburg, Martin C. Feiters, Nan Eshuis, Sybren S. Wijmenga, Floris P. J. T. Rutjes, Ruud L. E. G. Aspers, Marco Tessari |
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| Rok vydání: | 2016 |
| Předmět: |
Coupling constant
Nuclear and High Energy Physics Proton 010405 organic chemistry Chemistry Biophysics Analytical chemistry Pulse sequence Synthetic Organic Chemistry 010402 general chemistry Condensed Matter Physics J-coupling 01 natural sciences Biochemistry Molecular physics Homonuclear molecule 0104 chemical sciences Magnetization Hyperpolarization (physics) Singlet state Biophysical Chemistry |
| Zdroj: | Journal of Magnetic Resonance, 265, 59-66 Journal of Magnetic Resonance, 265, pp. 59-66 |
| ISSN: | 1090-7807 |
| DOI: | 10.1016/j.jmr.2016.01.012 |
| Popis: | SABRE (Signal Amplification By Reversible Exchange) nuclear spin hyperpolarization method can provide strongly enhanced NMR signals as a result of the reversible association of small molecules with para-hydrogen (p-H2) at an iridium metal complex. The conversion of p-H2 singlet order to enhanced substrate proton magnetization within such complex is driven by the scalar coupling interactions between the p-H2 derived hydrides and substrate nuclear spins. In the present study these long-range homonuclear couplings are experimentally determined for several SABRE substrates using an NMR pulse sequence for coherent hyperpolarization transfer at high magnetic field. Pyridine and pyrazine derivatives appear to have a similar ∼1.2 Hz (4)J coupling to p-H2 derived hydrides for their ortho protons, and a much lower (5)J coupling for their meta protons. Interestingly, the (4)J hydride-substrate coupling for five-membered N-heterocyclic substrates is well below 1 Hz. |
| Databáze: | OpenAIRE |
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