Photochemical Generation of Silicon-centered Radicals and their Reactions

Abstract

This chapter is organized according to classes of silicon-containing compounds that give rise to silyl-centered radicals through photolytic methods, then reviewing their reactivity, their spectroscopic data, and their possible applications. Such diverse sources of silicon compounds include simple hydrosilanes, alkyl-, alkyl-aryl, and arylsilanes, disilanes, polysilanes, acylsilanes, silacycloalkanes, and silyl ethers. Photochemically- induced homolytic cleavage of Si-X bonds (where X can be B, Ge, or other elements) will also be described as available sources of silyl radicals. The study on the photochemistry of different organic compounds, which bear common siliconprotective groups, their photolytic de-protection reactions, and the silyl radicals generated thereafter, will be presented. It is worthwhile emphasizing that this chapter covers only silicon-centered radicals that are directly or indirectly generated by the interaction of silicon-containing compounds with light, thus excluding silyl radicals that are obtained through thermal methods. Thermal-decomposition methods for the production of silicon-centered radicals are widely distributed, and constitute the subject of future review articles. This chapter also circumvents other silicon-based intermediates, such as silylenes, silenes, and radical ions of silicon, which are also the subject of future review studies. Throughout the chapter it will become apparent that the photochemical generation of silicon-centered radicals is oftenly accompanied by the production of other kinds of reactive silicon intermediates (silicon−centered biradicals, silylenes, silenes, etc.).