Pocket and antipocket conformations for the CH₄@C₈₄ endohedral fullerene

Abstract

ABSTRACT:The endohedral fullerene CH 4 @C 84 has been studied using density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2). In addition to the structure with a COH bond of CH 4 in a tetrahedral pocket conformation, we find an alternative minimum, very close in energy (6.3-9.5 kJ/mol higher according to the level of theory), with the methane inverted, which we call the antipocket conformation. Computed IR spectra are reported for CH 4 @C 84 and also for the reference system CH 4 @C 60 . The calculated vibrational levels, in a harmonic approximation, reveal close-lying translational, librational, and shell-vibrational modes. The results are also presented for the isoelectronic species NH 4 ϩ @C 60 .

Molecular geometries, electronic properties, and vibrational spectroscopic studies of endohedral metallofullerenes TM@C24 and TM@C24H12 (TM = Cr, Mo, and W)

“…In the meantime, some endohedral complexes doped with various small molecules or ions have also been obtained [34][35][36][37][38][39][40][41][42][43][44][45][46][47]. For example, Gan [36] have reported the structures and stabilities of dimetallofullerenes M 2 @C n (M = Sc and La, n = 72, 76, 78, 80, and 84) with local density functional (LDA) method, and demonstrated that the two metallic atoms always tend to separate as long as possible inside fullerene cage.…”

“…Yumura et al [39] have discussed the possible isomers of the Ti 2 @C 80 metallofullerene using the hybrid DFT-B3LYP functional, and found that Ti bindings over the hexagon ring are energetically preferable relative to those over a junction between hexagon and pentagon rings. Rehaman et al [44] have studied the pocket and antipocket conformations of CH 4 @C 84 using density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2), and found that the antipocket conformation have an alternative minimum.…”

Understanding why rheumatoid arthritis patient treatment preferences differ by race

“…[4–8] A great number of applications ascribe mainly to their unique physical and chemical properties such as electrical conductance, ferroelectricity, nonlinear optical properties, and so forth. Especially, the hollow fullerene cages can be modified with the targeted structures and interesting electronic features by means of the endohedral atoms[9–17] and small molecules[18–22] or exohedral species,[23–25] and then establish the novel form of carbon materials, and extend the scope of applications. For understanding their potential applications, the structural and electronic properties of each fullerene derivative are an essential prerequisite and should be first explored.…”

A computational study of the endohedral fullerene GeH4@C60

“…Erkoc and Turker [26] presented the structures and electronic properties of XH 4 @C 60 (X = C and Si) by means of semiempirical calculation. Dodziuk et al [27] and Rehaman et al [28] reported the energies and structures of endohedral fullerenes CH 4 @C n (n = 60, 70, 76, 80, 82 and 84) by means of molecular mechanics methods and DFT, respectively. Additionally, metal-hydride molecules inside the cage, such as ZrH 4 @C 60 , have also been studied by employing quantum chemical calculations [29].…”