Rovibrational Motion of CO in SolidC60

Dynamics of CO Molecules in SolidC60as a Function of Cavity Size

“…When the C 60 molecules are orientationally ordered, the symmetry of the site is reduced to S 6 . It is found that the six symmetry equivalent minima off the C 3 axis are the global minima, while the two symmetry equivalent minima on the C 3 axis represent local minima [4]. In Fig.…”

“…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]. Recently, we have demonstrated that CO molecules can be efficiently squeezed into the octahedral sites of solid C 60 , and we have studied the dynamics of CO in the interstitial sites using infrared (IR) absorption and 13 C nuclear magnetic resonance (NMR) spectroscopy [4]. Under ambient conditions, the dynamics of CO in solid C 60 is observed to be the dynamics of a "stick" in a rigid square box with walls that are curved inward, which as such is an example of a classically chaotic system [5].…”

“…In this potential we calculate the center of mass, i.e., translational, motions of the CO molecule, as well as its (hindered) rotations, implying a total of 5 degrees of freedom. Because of the rather complex shape of the van der Waals potential surface, there is strong translation-rotation coupling and quantum mechanical tunneling between equivalent minima, so that a full fivedimensional quantum mechanical treatment [4,19] has to be given. First we calculate the bound states for a rigid CO molecule inside this potential, and next, with the aid of a dipole function which represents the CO (4) stretch transition dipole moment, we synthesize the room temperature IR absorption spectrum.…”

“…CO intercalated C 60 samples [4] are loaded in the sample chamber of a compact high-pressure cell and their IR transmission spectrum is recorded using a Fourier transform infrared absorption spectrometer (Bruker IFS 66v) in combination with an IR microscope. The sample chamber is a small 0.5 mm diameter hole drilled in a brass gasket that is preindented down to approximately 30 mm thickness.…”

Intercalation of fullerite C60 with N2 molecules. An investigation by x-ray powder diffraction

“…are orientationally disordered and rotate quite freely in the interstitial sites of the lattice [7,[12][13][14][15]. However, below T c the nonspherical S 6 symmetry of the force field associated with the octahedral sites, with its specific noncentral interaction with the surrounding C 60 molecules, promote localization of the interstitial guest molecule, as well as inducing it to align in certain orientations with respect to the symmetry axes of the C 60 lattice [13][14][15]. This in turn can influence the lattice dynamics, the phase transition and even the structure of the C 60 host matrix.…”