A G3(MP2B3) investigation on the structures and properties of silaprismanes

Abstract

High level G3(MP2B3) calculations have been performed to study the structures and properties of [ n]silaprismanes and poly[ n]silaprismanes. The similarity and differences of these molecules were systematically studied in terms of their structures, binding energy, strain energy, heat of formation, and HOMO–LUMO gaps, etc. Our calculations reveal that the five-membered silaprismane ( n = 5) have relatively high stability among the [ n]silaprismanes studied. Considering that only the three- ( n = 3) and four-membered ( n = 4) silaprismane derivatives have been synthesized up to now, our calculations provide an interesting target for future synthesis. In addition, we designed a series of multi-layer silaprismane whose HOMO–LUMO gaps decrease with the number of layers. It is then expected that the silicon nanotubes are semi-conductive with small HOMO–LUMO gaps. The comparisons between silaprismane and hydrogenated silicon fullerene were also made and discussed.