Averaging of nuclear modulation artefacts in RIDME experiments.
The presence of artefacts due to Electron Spin Echo Envelope Modulation (ESEEM) complicates the analysis of dipolar evolution data in Relaxation Induced Dipolar Modulation Enhancement (RIDME) experiments. Here we demonstrate that averaging over the two delay times in the refocused RIDME experiment allows for nearly quantitative removal of the ESEEM artefacts, resulting in potentially much better performance than the so far used methods. The analytical equations are presented and analyzed for the case of electron and nuclear spins S=1/2,I=1/2. The presented analysis is also relevant for Double Electron Electron Resonance (DEER) and Chirp-Induced Dipolar Modulation Enhancement (CIDME) techniques. The applicability of the ESEEM averaging approach is demonstrated on a Gd(III)-Gd(III) rigid ruler compound in deuterated frozen solution at Q band (35GHz).
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
Katharina
K
Keller
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
Andrin
A
Doll
Faculty of Chemistry and Center for Molecular Materials (CM(2)), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Mian
M
Qi
Faculty of Chemistry and Center for Molecular Materials (CM(2)), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany.
Adelheid
A
Godt
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland.
Gunnar
G
Jeschke
Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland. Electronic address: maxim.yulikov@phys.chem.ethz.ch.
Maxim
M
Yulikov
EPR; Electron spin envelope modulation suppression; Gadolinium; Paramagnetic metal ions; Q band; RIDME