K. Lynch et al., FT-RAMAN SPECTROSCOPIC STUDIES OF C-60 AND C-70 SUBSEQUENT TO CHROMATOGRAPHIC-SEPARATION INCLUDING SOLVENT EFFECTS, Journal of physical chemistry, 99(20), 1995, pp. 7985-7992
C-60/C-70 containing soot was produced by are-vaporization of graphite
. The chromatographic separation of soot yielded fairly pure C-60 and
C-70 samples. High-resolution FT-Raman spectra of C-60 and C-70 specim
en as well as C-60 and C-70 solutions including polarization measureme
nts are recorded. Compared to the spectrum of solid C-60, some Raman b
ands of the C-60 solution change their position and shape. Even the pu
rest commercial C-60 samples contain solvent inclusions (impurities) i
n the order of some percentage. The chromatographic separation combine
d with Raman polarization measurements of solutions allows an evaluati
on of the fundamental vibrations of the C-60 molecule. Its assignment,
in accordance with the group theoretical expectation, is proposed. Th
e existence of small amounts of C-60 isomers (symmetry, e.g., C-2v, D-
2h, D-2d) in icosahedral C-60 (I-h) is affirmed based on the polarizat
ion measurements. For C-70 the most extended set of Raman frequencies
is presented.