MNDO study of boron-nitrogen analogs of buckminsterfullerene

Abstract

are obtained if the metal substitution does not alter the first shell too much.Examination of Table II shows the number of different factors that are important in determining the EPA. The Born estimate of the reaction field interaction is the most significant. The cavity radius increases by about 0.25 Á in going from ZnCA to CdCA. This leads to a relative stabilization of ZnCA in the protonated state while the high-pH complex has roughly constant Bom energy for all the dications. Consequently, the spread in the EPA is reduced by about 7 kcal/mol relative to the SCF cluster values. In one case, the higher moment contributions to the Born energy have a qualitative effect on the relative EPA values. The reaction field stabilization energy of the MnCA high-pH model is smaller than that for the larger CdCA cluster. This is because of the larger M-O-H angle found for Mn (see Table I), giving a more symmetric cluster with smaller dipole and quadrupole moments leading to a smaller reaction field energy.

Structure and stability of BN microclusters: Ab initio calculations for (BN)n (n = 2–4)

“…They found that the dominant series of clusters were the ions (B,N,-l)+ for n = 2-9. Recently, BN equivalents of the vapor-phase allotropic modifications of carbon have been conjectured [2] and the existence of closed fuilerene structures (i.e., B30N30) synthesized from borazine have been reported [3]. Resemblances between BN and C isoelectronic clusters in the vapor-phase state are less known that they are in their corresponding phases, even though the isoelectronic principle suggests the existence of similar geometrical skeletons.…”

Bonding and electronic properties of a multicomponent fullereneC12B24Kobayashi1, Kurita2 1993Phys. Rev. Lett.352130View full textAdd to dashboardCite

“…Xia et al and Bowser, Jelsky, and George [3] have proposed a cage-shaped Q2B24N24 cluster, with six C-C, twelve C-B, twelve C-N, and sixty B-N nearest-neighbor interactions, and concluded from calculations of total energies, enthalpies of formation, and enthalpies of product reactions by the modified neglect of differential overlap (MNDO) method that Q2B24N24 rivals C 6 o with respect to thermodynamic stability. Our previous calculations [4,5] with local-density and spin-restricted approximations clarified that C59B, C59N, C 58 B 2 , C 58 N 2 , and C 58 BN have smaller bond energies compared with C6o-It is then expected that C12B24N24 is less stable than C60, at least from the viewpoint of static stability.…”

“…We considered the same geometry as that proposed by Xia et ai [3], because it does not have the relatively weak B-B and N-N bonds and may be stable. The optimized bond lengths, bond order (the number of electrons contributing to the bonding, which is estimated from the overlap population analysis), bond energy, and energy gap between HOMO and LUMO are listed in Table I, where those of Ceo are also shown for comparison.…”

Inorganic Nanoparticles with Fullerene‐like Structure and Nanotubes; Some Electrochemical and Photoelectrochemical Aspects

“…Earlier, a few groups used powerful theoretical tools to calculate the stability, bandstructure, and other physical properties of B x C y N z nanotubes and fullerene-like nanoparticles [23,[113][114][115][116][117][118]. A few striking conclusions emerged from these studies.…”