Spin Probe for Dynamics of the Internal Cluster in Endohedral Metallofullerenes

Abstract

Endohedral metallofullerenes (EMFs) are constructed by fullerene cages encapsulating various metal atoms or metal clusters, which usually take certain motion. However, due to the untouchable endohedral dynamics relates with many factors, it is still a challenge to image the motion of internal species until today. Recently, the electron spin was found to be a sensitive probe to detect the motion of internal species in EMFs. Moreover, this technique can be widely applied for many metallofullerenes, i.e., for paramagnetic EMFs, the unpaired electron spin is a natural probe for the endohedral dynamics; and for those diamagnetic EMFs, an electron can be introduced to produce spin-active EMF molecules. Based on the analyses of hyperfine coupling constants (hfcc), g-factors, and line patterns of ESR spectra for EMFs, the spin centers and endohedral dynamics can be deduced. It was revealed that the spin probes could provide unexpected information about the dynamics of the internal clusters in EMFs. Through changing temperature, exohedral addition, and suparmolecular assembly, the motion of the internal species in EMFs can be manipulated as well reflected by the spin probe. These studies revealed that the spin in EMFs would exhibit promising applications in quantum sensing and molecular machine technology.