Spin shuttle is a term coined for endofullerene molecules which encage and protect an atom or molecule with an open electron shell.
Such molecules are candidates for single molecule magnets and have a great potential as building blocks in molecular spintronics.
A single molecule magnet is a molecule that retains its magnetization direction for a long time, i.e. displays hysteresis.
The first single molecule magnet spin shuttle was DySc2N@C80
(Westerström et al. Journal of the American Chemical Society 134, 9840 (2012)) (article).