Long Van Duong

Electronic Structure and Thermochemical Parameters of the Silicon-Doped Boron Clusters BnSi, with n = 8–14, and Their Anions

We performed a systematic investigation on silicon-doped boron clusters BnSi (n = 8-14) in both neutral and anionic states using quantum chemical methods. Thermochemical properties of the lowest-lying isomers of BnSi(0/-) clusters such as total atomization energies, heats of formation at 0 and 298 K, average binding energies, dissociation energies, etc. were evaluated by using the composite G4 method. The growth pattern for BnSi(0/-) with n = 8-14 is established as follows: (i) BnSi(0/-) clusters tend to be constructed by substituting B atom by Si-atom or adding one Si-impurity into the parent Bn clusters with n to be even number, and (ii) Si favors an external position of the Bn frameworks. Our theoretical results reveal that B8Si, B9Si(-), B10Si and B13Si(-) are systems with enhanced stability due to having high average binding energies, second-order difference in energies and dissociation energies. Especially, by analyzing the MOs, ELF, and ring current maps, the enhanced stability of B8Si can be rationalized in terms of a triple aromaticity.

Silicon doped boron clusters: how to make stable ribbons?

A doping of small boron clusters with silicon atoms leads to the formation of stable boron nanoribbon structures. We present an analysis on the geometric and electronic structure, using MOs and electron localization function (ELF) maps, of boron ribbons represented by the dianions B10Si22− and B12Si22−. The effect of Si dopants and the origin of the underlying electron count [⋯π2(n+1)σ2n] are analyzed. Interaction between both systems of delocalized π and σ electrons creating alternant B–B bonds along the perimeter of a ribbon induces its high thermodynamic stability. The enhanced stability is related to the self-locked phenomenon.