Structural, vibrational, spectroscopic, NMR and quantum chemical studies on fullerene and bromofullerenes

Abstract

The most stable, optimized structures of fullerene (C60) and bromofullerenes (C60Br6) molecules were predicted by the density functional theory calculations using B3LYP method with 6311G(d,p) basis set. The obtained parameters were estimated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Bromofullerene (C60Br6) was architectured by directly bonding with bromine atom at C60 reactive sites. Theoretically calculated vibrational wavenumbers were assigned and compared. Ultraviolet–visible spectrum was mimicked by Polarizable Continuum model. The 13C NMR spectra were simulated by nuclear magnetic tensor GIAO for C60 and C60Br6 relative to tetramethyl silane. The molecular electrostatic potential surface was simulated. The transition between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) revealed different charge transfer possibilities which occur for the molecule and other related molecular properties were computed and tabulated. Natural bond orbital (NBO) analysis was carried out to image the charge transfer between the localized bonds and lone pairs of the electrons. The enhanced reactivity and peculiar energy gap by the substitution of bromine in fullerene pave way for designing the optoelectronic devices and bioactive molecules which will be useful in the field of sensors and carbon nano medicine.