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

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.