Detalles de publicación
PP 010049
Low and High Temperature Infrared Spectroscopy of C60 and C70 Fullerenes
1IstitutoNazionale diAstrofisica – Osservatorio Astrofisico di Catania, Catania, Italy
2Actinium Chemical Research, Rome, Italy
3Instituto de Astrofisica de Canarias, Tenerife, Spain
The FT-IR spectra of the fullerenes C60 and C70 have been recorded in the temperature
range between 523 K (+250C) and 93 K (-180C). As a general rule, it has been
observed a shift of the infrared absorption bands toward higher frequencies at lower
temperatures. As expected, at 93 K the infrared spectra appear better resolved with
sharper absorption bands and higher intensity than the same bands measured at higher
temperature. All the infrared spectra of the present study have been made on samples
embedded in KBr matrix and all data were extrapolated to 0 K. These spectral data at
extremely low temperatures are of paramount importance for astrochemical search of
these molecules in space. By comparing the gas phase spectra of both C60 and C70
fullerenes extrapolated to 0 K with the data taken in KBr matrix, the gas phase spectral
bands were found systematically shifted 5-10 cm-1 toward higher frequencies than the
same bands recorded in KBr. Similarly, the matrix effect is appreciable also when the
spectral data taken in KBr are extrapolated to>1000 K. In such case the band position of
C60 and C70 fullerenes in the gas phase are shifted to lower frequencies than the
extrapolation data taken in KBr matrix.
range between 523 K (+250C) and 93 K (-180C). As a general rule, it has been
observed a shift of the infrared absorption bands toward higher frequencies at lower
temperatures. As expected, at 93 K the infrared spectra appear better resolved with
sharper absorption bands and higher intensity than the same bands measured at higher
temperature. All the infrared spectra of the present study have been made on samples
embedded in KBr matrix and all data were extrapolated to 0 K. These spectral data at
extremely low temperatures are of paramount importance for astrochemical search of
these molecules in space. By comparing the gas phase spectra of both C60 and C70
fullerenes extrapolated to 0 K with the data taken in KBr matrix, the gas phase spectral
bands were found systematically shifted 5-10 cm-1 toward higher frequencies than the
same bands recorded in KBr. Similarly, the matrix effect is appreciable also when the
spectral data taken in KBr are extrapolated to>1000 K. In such case the band position of
C60 and C70 fullerenes in the gas phase are shifted to lower frequencies than the
extrapolation data taken in KBr matrix.