Electronic structure, vibrational stability, infra-red, and Raman spectra of B24N24 cages

Abstract

We examine the vibrational stability of three candidate structures for the B 24 N 24 cage and report their infra-red (IR) and Raman spectra. The candidate structures considered are a round cage with octahedral Øsymmetry, a cage with S 4 symmetry that satisfies the isolated square rule, and a cage of S 8 symmetry, which combines the caps of the (4,4) nanotube, and contains two extra squares and octagons. The calculations are performed within density functional theory, at the all electron level, with large basis sets, and within the generalized gradient approximation. The vertical ionization potential (VIP) and static dipole polarizability are also reported. The S 4 and S 8 cages are energetically nearly degenerate and are favored over the Øcage which has six extra octagons and squares. The IR and Raman spectra of the three clusters show notable differences providing thereby a way to identify and possibly synthesize the cages.

Theoretical infrared, Raman, and optical spectra of theB36N36cage

“…The vertical and adiabatic ionization potentials as well as static dipole polarizability are also reported. [3,4,5,6,7,8,9,10].On the experimental side, there are also a few reports of synthesis of hollow BN structures [10,11,12,13,14].In a series of experiments by Oku and coorkwers, boron nitride clusters of different sizes were reported [10,11,12].Perhaps the most interesting result of these works was the production of B 24 N 24 in abundance. We performed theoretical calculations [8,9] …”

“…We performed theoretical calculations [8,9] [14]. From the high resolution transmission electron microscopy images (HRTEM), they observed single-shelled cages of size 9-10Å, with rectanglelike outlines.…”

“…The vertical and adiabatic ionization potentials as well as static dipole polarizability are also reported. [3,4,5,6,7,8,9,10].…”

Photoabsorption spectra of boron nitride fullerenelike structures

“…In contrast, for B 24 N 24 , the isomers with the lower S 8 and S 4 symmetries are computationally found more stable than the most symmetric isomer with the O symmetry. 14,15 This is due to the high number of energetically less favorable octahedral rings in the O-symmetric structure. However, the differences in total energy are small, of the order of 0.1 eV/ at.…”

A Nano Catalyst of CoFe2o4@ B18N18 as a Novel Material

“…Due to the closely structures between C-C and B-N units, large efforts have been done recently to "BN" fullerenes, which has excellent properties like structural stability, heat resistance and insulation 46,47 . As the thermodynamic mechanism of BN growth (from nuclei) is still not well known for those nanotubes, a comprehensive theoretical simulation continue to attract enhanced attention 48 .…”