Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 831-836.doi: 10.3866/PKU.WHXB20110412


Stability and Aromaticity of XB6+ (X=C, Si, Ge, Sn, Pb) Clusters

GONG Liang-Fa, WU Xin-Min, LI Wei, QI Chuan-Song   

  1. College of Chemical Engineering, Beijing Institute of Petro-Chemical Technology, Beijing 102617, P. R. China
  • Received:2010-12-29 Revised:2011-01-30 Published:2011-03-29
  • Contact: WU Xin-Min


The geometries, stability and chemical bonding of XB6+(X=C, Si, Ge, Sn, Pb) clusters were investigated using ab initio (MP2) and density functional theory (DFT: B3LYP and B3PW91) methods. Analytical gradients with polarized split-valence basis sets (6-311+G(d)) were used for B, C, Si, and Ge. The relativistic effective core potential with the LANL2DZ basis sets were chosen for Sn and Pb. The results show that the Cs symmetric pseudo-planar XB6+(X=C, Si, Ge, Sn, Pb) structures are the global minima on the potential energy surfaces, which are more stable than the C6v symmetric pyramidal and C2 symmetric quasi-pyramidal structures. We carried out a natural bond orbital (NBO) analysis of all these minima at the B3LYP level, and calculated and discussed the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO) energy gaps, the molecular orbitals (MO), and the nucleus-independent chemical shifts (NICS) of the most stable structure. The nature of the X―B and B=B bonds in these minimum structures and the aromatic characteristics (σ and π) of the most stable configuration were analyzed at the B3LYP level.

Key words: Density functional theory, Ab initio calculation, Hetero-polyboron cluster, Aromaticity


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