Electron spin echo envelope modulation (ESEEM) has been observed for the first time from a coupled heterospin pair of electron and nucleus in liquid solution. Previously, modulation effects in spin-echo experiments have only been described in liquid solutions for a coupled pair of homonuclear spins in nuclear magnetic resonance or a pair of resonant electron spins in electron paramagnetic resonance. We observe low-frequency ESEEM (26 and 52 kHz) due to a new mechanism present for any electron spin with S>12 that is hyperfine coupled to a nuclear spin. In our case these are electron spin (S=32) and nuclear spin (I=1) in the endohedral fullerene N@ C60. The modulation is shown to arise from second-order effects in the isotropic hyperfine coupling of an electron and N14 nucleus.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry