IR spectroscopic analysis of heterohedral metallofullerenes

The infrared spectroscopies (IR) and vibrational modes of ten heterohedral metallofullerenes C19M (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) are theoretically simulated by density functional theory (DFT) method and applying high accuracy basis set 6-311G++(d,2p) with G09W. The obtained IR spectra bands from 0 cm-1 to 1400 cm-1 are classified into three broad spectral regions: 200-400 cm- 1, 600-800 cm-1 and 1100-1300 cm-1 characterizing transition metal (M), bending modes of C-C bonds at low frequency and stretching modes of C-C bonds at high frequency, respectively. The results show that there is a direct linear relationship between the dipole moments and the intensity of IR peaks at the first spectral region 200-400 cm-1. In addition, the IR spectroscopy exhibits remarkable dependence on the type of transition metals. Thus, IR spectroscopic technique could be adopted to identify the doping element of metallofullerenes C19M effectively. Finally, the calculated IR spectra could be used to link and explain unidentified infrared bands to the interstellar spectral data.

Automated summary

The infrared spectroscopies and vibrational modes of ten heterohedral metallofullerenes C19M were theoretically simulated using density functional theory (DFT) method. The results showed that the obtained IR spectra bands could be classified into three broad spectral regions characterizing transition metal (M), bending modes of C-C bonds, and stretching modes of C-C bonds. The intensity of IR peaks at the first spectral region 200-400 cm-1 exhibited a direct linear relationship with the dipole moments. Moreover, the IR spectroscopy was found to depend on the type of transition metals, making it useful for the identification of doping elements in metallofullerenes C19M. Finally, the calculated IR spectra could be used to link and explain unidentified infrared bands to the interstellar spectral data.