Orientational Dynamics of theSc3Trimer inC82: An EPR Study

Dynamics of CO Molecules in SolidC60as a Function of Cavity Size

“…A large part of the transition from translationally and rotationally free molecules in a box to rigidly oriented molecules can thus be studied experimentally, and accurately described theoretically. An intriguing possibility offered by the fullerenes, as already remarked by Kroto et al in 1985 [1], is to experimentally study the dynamics of nearly free atoms and molecules confined to the inside of the carbon cages [2]. Soon after a production method for macroscopic amounts of fullerenes was developed and first details about the structure of solid C 60 became available, it was demonstrated that the sites in between the C 60 spheres in the solid are equally well suited for holding atoms and small molecules [3].…”

Rovibrational Motion of CO in SolidC60

“…1(b). Small molecules inside fullerene cages have been suggested to form an ideal system for the study of nearly free molecular rotation in the solid, and experimental evidence for the motion of a scandium trimer inside a C 82 fullerene cage has, for instance, been reported [16]. In addition, it has been pointed out that small polar molecules trapped inside the highly symmetric C 60 cage might be considered the building blocks for an ideal electric dipolar lattice [17].…”

W- and X-band EPR investigation of Sc3@C82

“…However, investigations in solvents of vastly different viscosity showed no strong effect on the linewidth. 6,15 Therefore, spin-rotational coupling seems to be negligible in this system. The linewidth is, however, much larger than in monoendohedral Sc@C 82 , which is probably due to the internal reorientation of the Sc triangle, as will be discussed later.…”

“…Some of the carbon atoms have been marked for further discussion in the following text. ESR spectroscopy reveals an appreciably larger linewidth for Sc 3 jump-like motion of the scandium atoms inside the cage, 5 to a rotation of the Sc 3 -triangle 6 and to a dynamic distortion of the triangle. 7 Recently a synchrotron powder diffraction measurement has been published, 8 which identifies the scandium trimer at an off-center position, as shown in Fig.…”