Application of the Correlation Method to Vibrational Spectra of C60 and Other Fullerenes:: Predicting the Number of IR- and Raman-Active Bands
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Kazuo Nakamoto [1] ; Michael A. McKinney [1]
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[1] Marquette University
Marquette University
City of Milwaukee, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 77, Nº 6 (June), 2000, págs. 775-775
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
The C60 molecule (Buckyball/soccer ball) exhibits only 4 IR and 10 Raman bands although it possesses 174 (3 x 60 - 6) normal vibrations. This striking reduction in the number of observed bands is evidently due to the molecule's extremely high symmetry (Ih point group). First, the 120 symmetry elements of its truncated icosahedral structure are identified and the local (site) symmetry of the carbon atoms (Cc) is determined. Use of molecular models greatly facilitates the process in determining the local and molecular symmetries. Then the correlation method is used to derive a table that classifies the 174 normal vibrations into the respective symmetry species of the Ih point group. In this method, symmetry properties of atomic displacements in terms of the local point group (Cc) are correlated with those in terms of the molecular point group (Ih). After the normal vibrations are classified into respective symmetry species, the numbers of IR- and Raman-active vibrations can be determined by the symmetry selection rules for IR and Raman spectra. The vibrational spectra of C60 and C70 (rugby ball) are analyzed by the above procedure, and the results obtained for C28, C32, C50, and dodecahedrane are provided.
