A 13 C-Labeled Triarylmethyl Radical as an EPR Spin Probe Highly Sensitive to Molecular Tumbling

Angew Chem Int Ed Engl. 2020 Sep 14;59(38):16451-16454. doi: 10.1002/anie.202006591. Epub 2020 Jul 21.


A stable triarylmethyl spin probe whose electron paramagnetic resonance (EPR) spectrum is highly sensitive to molecular tumbling is reported. The strong anisotropy of the hyperfine coupling tensor with the central carbon of a 13 C1 -labeled triarylmethyl radical enables the measurement of the probe rotational correlation time with applications to measure microviscosity and molecular dynamics.

Keywords: EPR spectroscopy; isotopic labeling; microviscosity; spin probes; triarylmethyl radical.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Carbon Isotopes
  • Electron Spin Resonance Spectroscopy
  • Methane / analogs & derivatives*
  • Methane / chemistry
  • Molecular Dynamics Simulation
  • Molecular Structure


  • Carbon Isotopes
  • methyl radical
  • Carbon-13
  • Methane