Theoretical study of fullerene derivatives: C40H4 and C40X4 cluster molecules

Abstract

Herein we demonstrate that the C40 cluster molecule is easily formed to Td symmetry structure and its ground state is 5A2 open shell with four unpaired electrons. These four unpaired electrons are located at the tip points of the Td symmetry structure. This work also indicates that these four unpaired electrons can easily react with a single valence atom, such as hydrogen or halogen atoms, to form a stable carbon hydrogen cluster molecule, C40H4, and carbon halogen cluster molecules, C40X4 (X=F, Cl, Br, I), respectively. The PM3 semiempirical molecular orbital method from Gaussian 94W computer program package was applied very well to these cluster molecules. According to the results in this study, the structures of geometrical optimization, ionization potential, energy gap, heat of formation, atomization energy, vibration frequency, and the remaining data of C40H4 and C40X4 cluster molecules. The above‐calculated data prove that these unknown cluster molecules are stable and have a stable capacity similar to 1,3,5,7‐tetrahaloadamantane molecules. They can be possibly synthesized experimentally in the near future. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 273–284, 1998

The evolutions of the structure stability, vibrational frequency, frontier orbital, and electronegativity of the unconventional exohedral fullerenes C64X4 (X=H, F, Cl, Br, and I): A density functional study

“…Commonly, hydrogen atom or halogen atoms can be all used to stabilize the fullerene cage, such as C 28 [9][10][11][12] and C 40 [13] and so on. In addition, the fluorination, chlorination, bromination, and iodination of fullerenes, under controlled conditions, can lead to the isolation of different stable compounds, such as C 20 F 20 [15], C 36 X n (X = F, Cl, and Br, n = 2, 4, 6, and 12) [16], C 50 X 10 (X = F, Cl, and Br) [8], C 60 F 24 [17], C 50 Cl 12 [18,19], C 60 X 24 (X = Br and I) [20], and C 70 I n (n = 2 and 17) [20].…”

“…It can be seen from the table that the v of C 64 X 4 (X = F, Cl, Br, and I) decreases with the increased atomic number of X, similar to the cases of C 28 X 4 (X = F, Cl, Br, and I) [9][10][11][12] and C 40 X 4 (X = F, Cl, Br, and I) [13]. The g decreases as X progresses down from F to I, thus, C 64 F 4 is more stable than others.…”

“…For example, the unconventional C 50 is stabilized by adsorbing 10 hydrogen atoms or halogen atoms on the vertexes of five two-fused pentagons to form stable C 50 H 10 [7] and C 50 X 10 (X = F, Cl, and Br) [8], respectively. This kind of exciting examples also include C 28 X 4 (X = H, F, Cl, Br, and I) [9][10][11][12] and C 40 X 4 (X = H, F, Cl, Br, and I) [13] and so on.…”