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A comparative study on the Ge 6 C 14 heterofullerene nanocages: a density functional survey
Author(s) -
Koohi M.,
Shariati M.,
Soleimani Amiri S.
Publication year - 2017
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.3678
Subject(s) - nanocages , heteroatom , chemistry , germanium , density functional theory , computational chemistry , crystallography , doping , molecular vibration , chemical bond , homo/lumo , bond length , silicon , chemical physics , molecule , crystal structure , organic chemistry , condensed matter physics , catalysis , ring (chemistry) , physics
Ten C 14 Ge 6 heterofullerene isomers of C 20 have been investigated by density functional theory (DFT) methods with Becke 3‐Parameter (Exchange), Lee, Yang and Parr (B3LYP) functional at the 6‐311 + G*, 6‐311++G** and AUG‐cc‐pVTZ levels. In contrast to identical bonds in the latter, contractions of C═C double bonds are encountered at the expense of longer C―Ge bonds in the former. Vibrational frequency analysis confirms that all of the nanocages are true minima. In contrast to the common belief, for obtaining highly silicon‐doped stable heterofullerenes, that the silicon dopants must be completely isolated from each other by means of strong C═C double bonds. Here, linking the germanium substitutions together is an applicable strategy for obtaining highly doped stable isolated heterofullerenes since it avoids weak heteroatom─heteroatom bonds. Therefore, none of the computed heterofullerenes collapses to open, to deform, or to segregate fullerenic cages. As to band gaps (Δ E HOMO‐LUMO ), and nucleus‐independent chemical shifts at cage centers (NICS (0)), C 14 Ge 6 ‐2 immerges with the highest value. Hence, it is predicted to be the most stable against electronic excitation. It contains 2 Ge─Ge single bonds at the cap‐equatorial positions. On the other hand, as to zero‐point vibrational energy and heat of atomization (Δ H at ), C 14 Ge 6 ‐8 appears with the lowest and highest value, respectively. It contains 6 alternating germanium atoms in the equatorial and cap positions. Thus, it is predicted to be the most thermodynamically stable. So, germanium substitution leads to a high charge distribution on the surfaces of all the isomers specially C 14 Ge 6 ‐9 with +1.496 charged germanum atoms. C 14 Ge 6 isomers seem to be a good candidate for the hydrogen storage material.