Influence of Pressure on the Intramolecular Spin Exchange in a Short Imidazolium-Nitroxide Biradical

Boryana Mladenova-Kattnig, Günter Grampp, Alexander I. Kokorin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A short-chain imidazoline-type nitroxide biradical R5 NO–CH=N–N=C(CH3)–R5 N, B2, with nitroxide rings R5 N and R5 NO as 1-oxyl-2,2,5,5-tetramethyl-3-imidazoline and 1-oxyl-2,2,5,5-tetramethyl-3-N-oxide imidazoline, respectively, has been studied using X-band electron paramagnetic resonance (EPR) spectroscopy in CH3CN solutions at variable temperature T and pressure P. Changes of the solution viscosity on the intramolecular electron spin exchange in B2 is characterized by calculating the value of the exchange integral |J/a|, where a denotes the 14N hyperfine splitting (hfs) constant. It is revealed that the intramolecular dynamics in B2 do not follow the Debye–Stokes–Einstein law, while the Arrhenius dependence is fulfilled. Probable reasons of such behavior are discussed.

Original languageEnglish
Pages (from-to)327-334
Number of pages8
JournalApplied Magnetic Resonance
Issue number4
Publication statusPublished - 1 Apr 2017

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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