Field-dependent paramagnetic relaxation enhancement in solutions of Ni(II): What happens above the NMR proton frequency of 1 GHz?

Jozef Kowalewski (1) , Pascal Fries (2) , Danuta Kruk (3) , Michael Odelius (4) , Andrei Egorov (5) , Steffen Krämer (6) , Holger Stork (6) , Mladen Horvatić (6) , Claude Berthier (6)

1 Department of Materials and Environmental Chemistry
2 MEM - Modélisation et Exploration des Matériaux
3 Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Sloneczna 54, PL-10-710 Olsztyn, Poland
4 Department of Physics [Stockholm]
5 SPbU - St Petersburg State University
6 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble

An extended set of paramagnetic relaxation enhancement (PRE) data, up to the field of 32.9 Tesla, is reported for protons in an acidified aqueous solution of a Ni(II) salt in the presence and in the absence of added glycerol. For the 55% w/w glycerol sample, a distinct maximum in the PRE vs magnetic field curve is observed for the first time. The data are analysed using the Swedish slow-motion theory, including both the intramolecular (inner-sphere) and intermolecular (outer-sphere) contributions. The results indicate that estimating the outer-sphere part in the presence of the more efficient inner-sphere term is a difficult task.

Domaines: Matière Condensée [cond-mat]

Jozef Kowalewski, Pascal Fries, Danuta Kruk, Michael Odelius, Andrei Egorov, et al.. Field-dependent paramagnetic relaxation enhancement in solutions of Ni(II): What happens above the NMR proton frequency of 1 GHz?. Journal of Magnetic Resonance, 2020, 314, pp.106737. ⟨10.1016/j.jmr.2020.106737⟩. ⟨hal-02576102⟩