1. The effects of halogen elements on the opening of an icosahedral B12 framework
- Author
-
Thomas Heine, Liang Fa Gong, Wei Li, Lei Liu, Edison Osorio, and Xin Min Wu
- Subjects
Materials science ,Icosahedral symmetry ,FOS: Physical sciences ,General Physics and Astronomy ,Infrared spectroscopy ,02 engineering and technology ,010402 general chemistry ,Decomposition analysis ,01 natural sciences ,symbols.namesake ,Planar ,Physics - Chemical Physics ,Cluster (physics) ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Physical and Theoretical Chemistry ,Chemical Physics (physics.chem-ph) ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Gibbs free energy ,Crystallography ,Halogen ,symbols ,Density functional theory ,ddc:541 ,effects, halogen elements, icosahedral B12 framework ,0210 nano-technology - Abstract
The fully halogenated or hydrogenated B12X12²- (X = H, F, Cl, Br and I) clusters are confirmed to be icosahedral.Onthe other hand, the bare B12 cluster is shown to have a planar structure.Aprevious study showed that a transformation from an icosahedron to a plane happens when 5 to 7 iodine atoms are remained [P. Farràs et al., Chem. - Eur. J. 18, 13208–13212 (2012)]. Later, the transition was confirmed to be seven iodine atoms based on an infrared spectroscopy study [M. R. Fagiania et al., Chem. Phys. Lett. 625, 48–52 (2015)]. In this study, we investigated the effects of different halogen atoms on the opening of the B12 icosahedral cage by means of density functional theory calculations.We found that the halogen elements do not have significant effects on the geometries of the clusters. The computed infrared (IR) spectra show similar representative peaks for all halogen doped clusters. Interestingly, we found a blue-shift in the IR spectra with the increase in the mass of the halogen atoms. Further, we compared the Gibbs free energies at different temperatures for different halogen atoms. The results show that the Gibbs free energy differences between open and close structures of B12X7- become larger when heavier halogen atoms are presented. This interesting finding was subsequently investigated by the energy decomposition analysis.
- Published
- 2017