Centres Científics i Tecnològics UB

News

01.07.2024

New pulsed electron paramagnetic resonance spectrometer

The CCiTUB have acquired a new pulsed electron paramagnetic resonance spectrometer, thanks to the grant EQC2021- 007330-P funded by the Ministry of Science and Innovation and the European Union’s Next Generation EU funds (call corresponding to the year 2021) endowed with a financing amount of 1.325.000 euros.

The new equipment, CW/FT-EPR spectrometer System ELEXSYS E580XQ-10/12 of Bruker, incorporates cutting-edge technologies, such as the SpecJet-III digitizer and the VAMP-III video amplifier, offering a detection bandwidth of 1 GHz. With this innovative equipment, researchers will be able to carry out FT-EPR and Electron Spin Echo experiments, as well as advanced techniques such as ESEEM, 2D-HYSCORE, Pulse-ENDOR, SECSY, EXSY.

The equipment will allow to explore in depth fields such as chemistry, physics, nanotechnology and biomedicine, opening up new possibilities for the research of structural proteins, nanostructured materials, and complex chemical reactions.

Features

The equipment stands out for a series of features that increase its versatility and precision. These characteristics position the CW/FT ELEXSYS E580XQ as a reference in the analysis of paramagnetic species:

  • FT-EPR and Electron Spin Echo techniques: used as basic detectors to obtain the EPR spectrum and electron spin relaxation times (T1 and T2).
  • ESEEM and 2D-HYSCORE: allow to measure spin density distribution and distances through the hyperfine interaction between electronic and nuclear spins.
  • Pulse-ENDOR: it is used for the study of hyperfine interactions, including those of weakly coupled nuclei, and provides insight into the relaxation times of the system.
  • SECSY and EXSY: measure correlations and exchange rates.

This device is equipped with:

  • SpecJet-III digitizer and VAMP-III video amplifier: offer a detection bandwidth of 1 GHz.
  • Flexline probe heads: developed over years, they are a key part of the spectrometer.
  • Q-band: the ELEXSYS E 580 FT/CW X-band spectrometer can operate with a Q-band due to its multifrequency design.
  • Cryostats with He for all bands to enable variable temperature studies.

Technology Applications

It allows a wide variety of experiments to be carried out that are essential for advanced research in various scientific fields such as materials science, chemistry, physics, nanotechnology and biomedicine. These are some of the outstanding applications:

  • SECSY and EXSY: Spin echo correlation spectroscopy (SECSY) and exchange spectroscopy (EXSY) are two-dimensional techniques that allow for the correlation of spectral peaks and obtaining information about exchange rates. These experiments are standard on the E580 spectrometer and compatible with the predefined PulseSPEL programs.
  • ESEEM and 2D-HYSCORE: Electron spin echo envelope modulation (ESEEM) is used to measure hyperfine interaction (HFI) parameters between electron spins and nearby nuclear spins. The 2D-HYSCORE technique is ideal for powder and frozen solutions spectra, providing detailed structural and electronic information.
  • Pulse ENDOR: combines microwave and radiofrequency pulses to measure hyperfine interactions, providing detailed information on electron spin density, distances, and bond angles. It is particularly effective for strong hyperfine interactions between paramagnetic centers and nearby magnetic nuclei.
  • Electron relaxation measurements (T1 and T2): provide information on the dynamics and molecular structure. T1 reveals data on molecular collisions, excited-state coupling, and distances between paramagnetic centers, while T2 provides information on molecular relaxation, internal rotations, and dipolar and exchange interactions.

Funding

This equipment has been fully funded by European funds in the 2021 call for scientific-technical equipment acquisition from the Next Generation EU Fund, Recovery, Transformation and Resilience Plan. / Project EQC2021- 007330-P, with a total amount of 1.325.000 €.

Location

The CW/FT-EPR ELEXSYS E580 equipment is located in the CCiTUB magnetic measurements laboratory situated in the basement of the Faculty of Chemistry at the University of Barcelona.