Electronic Structure and Thermochemical Parameters of the Silicon-Doped Boron Clusters BnSi, with n = 8–14, and Their Anions
文摘
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 BnSi0/– 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 BnSi0/– with n = 8–14 is established as follows: (i) BnSi0/– 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.