Journal cover Journal topic
Magnetic Resonance An interactive open-access publication of the Groupement AMPERE
Journal topic
Discussion papers
https://doi.org/10.5194/mr-2020-7
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/mr-2020-7
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 19 Mar 2020

Submitted as: research article | 19 Mar 2020

Review status
This preprint is currently under review for the journal MR.

Distance measurement between trityl radicals by pulse dressed electron paramagnetic resonance with phase modulation

Nino Wili1, Henrik Hintz2, Agathe Vanas1, Adelheid Godt2, and Gunnar Jeschke1 Nino Wili et al.
  • 1Department of Chemistry and Applied Biosciences, Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland
  • 2Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany

Abstract. Distance measurement in the nanometer range is among the most important applications of pulse electron paramagnetic resonance today, especially in biological applications. The longest distance that can be measured by all presently used pulse sequences is determined by the phase memory time Tm of the observed spins. Here we show that one can measure the dipolar coupling during strong microwave irradiation by using an appropriate frequency- or phase-modulation scheme, i.e. by applying pulse sequences in the nutating frame. This decouples the electron spins from the surrounding nuclear spins and thus leads to significantly longer relaxation times of the microwave-dressed spins (i.e. the rotating frame relaxation times T1ρ and T2ρ) compared to Tm. The electron-electron dipolar coupling is not decoupled as long as both spins are excited, which can be implemented for trityl radicals at Q-band frequencies (35 GHz, 1.2 T). We show results for two bis-trityl rulers with inter-electron distances of about 4.1 nm and 5.3 nm and discuss technical challenges and possible next steps.

Nino Wili et al.

Interactive discussion

Status: open (until 16 Apr 2020)
Status: open (until 16 Apr 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Nino Wili et al.

Data sets

Distance measurements between trityl radicals by pulse dressed electron paramagnetic resonance with phase modulation: Raw Data, Processing Scripts, Simulations N. Wili, H. Hintz, A. Vanas, A. Godt, and G. Jeschke https://doi.org/10.5281/zenodo.3703052

Nino Wili et al.

Viewed

Total article views: 233 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
155 73 5 233 31 1 1
  • HTML: 155
  • PDF: 73
  • XML: 5
  • Total: 233
  • Supplement: 31
  • BibTeX: 1
  • EndNote: 1
Views and downloads (calculated since 19 Mar 2020)
Cumulative views and downloads (calculated since 19 Mar 2020)

Viewed (geographical distribution)

Total article views: 178 (including HTML, PDF, and XML) Thereof 178 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 02 Apr 2020
Publications Copernicus
Download
Short summary
Measuring distances between unpaired electron spins is an important application of electron paramagnetic resonance. The longest distance that is accessible is limited by the phase memory time of the electrons spins. Here we show that strong continuous microwave irradiation can significantly slow down relaxation. Additionally, we introduce a phase-modulation scheme that allows measuring the distance during the irradiation. Our approach could thus significantly extend the accessible distances.
Measuring distances between unpaired electron spins is an important application of electron...
Citation