Construction of Building Blocks for Highly Functional π-Electron Silicon Nanomaterials by First-Principles Calculations

Abstract

IntroductionSeveral building blocks of the -electron silicon system designed by our computational studies are reviewed in this paper. The target is the building blocks possessing a strictly genuine -conjugation. A common feature underlying the successfully designed building blocks is elucidated and discussed.Fullerene, polyacetylene, and graphene provide fascinating properties governed by electrons in the carbon system, and the researches of these materials were sparkled with Novel prizes in 1996, 2000, and very recently in 2010, respectively. Silicon is in the same group of the periodic table as carbon and thus has a potential ability to make another paradigm produced by the electrons. Ethylene (1, H 2 C=CH 2 ), acetylene (2, HC≡CH), and benzene (3, c-(CH) 6 ) are authentic building blocks of the -electron carbon system (Fig. 1). We computed recently the corresponding building blocks of the -electron silicon Abstract: This paper reviews our computational studies on several building blocks for highly functional π-electron silicon nanomaterials by the introduction of an anionic system. We insisted that the design of building blocks possessed strictly genuine electrons: -conjugation on planar/linear skeletons. Though silicon is in the same group of the periodic table as carbon, the geometric structure of the unsaturated silicon compounds is nonclassical: trans-bent at silicon-silicon double and triple bonds, and chair-like at a six-membered silicon ring. We have theoretically designed a linear siliconsilicon triple bond and a -symmetric six-membered silicon ring with extra electrons instead of conventional substituents such as alkyl, aryl, etc. We summarize here our main fi ndings and discuss the key points to realize the classical structure etc. in the -electron silicon system.