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Updated: Jul 2, 2025

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
Hyperpolarized long-lived spin state of methylene protons of 2-bromoethanol obtained from ethylene with
Simon V Babenko1, Sergey V Sviyazov2, Dudari B Burueva3
1Laboratory of Magnetic Resonance Microimaging, International Tomography Center, SB RAS, Novosibirsk 630090, Russia; V.V. Voevodsky Institute of Chemical Kinetics and Combustion, SB RAS, Novosibirsk 630090, Russia.
Abstract:
In this work we achieve a significant overpopulation (PLLS≈1%) of the long-lived spin state (LLS) of methylene protons in 2-bromoethan(2H)ol (BrEtOD) obtained in a reaction between ethylene with non-equilibrium nuclear spin order and bromine water. Given all protons in ethylene are magnetically equivalent, its nuclear states are classified into nuclear spin isomers (NSIM) with total spin I = 2,1,0. Addition of parahydrogen to acetylene produces ethylene with a population of only those NSIMs with I = 1,0. As a result of the reaction with bromine water the non-equilibrium spin order of ethylene is partly transferred to the singlet LLS involving the two methylene groups of BrEtOD. The 1H NMR signal enhancement (SE≈200) obtained as a result of the LLS readout is approximately equal to the SE of the hyperpolarized BrEtOD obtained with a single π/4 pulse. The LLS relaxation time (TLLS) was shown to be approximately 40 s (≈8T1) in the argon-bubbled sample.
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