Photochemical generation of siliconcentered radicals and their reactions

Abstract

This chapter is organized according to classes of silicon-containing compounds that giverise to silyl-centered radicals through photolytic methods, then reviewing their reactivity,their spectroscopic data, and their possible applications. Such diverse sources of siliconcompounds 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, orother elements) will also be described as available sources of silyl radicals. The study onthe photochemistry of different organic compounds, which bear common siliconprotectivegroups, their photolytic de-protection reactions, and the silyl radicals generatedthereafter, will be presented.It is worthwhile emphasizing that this chapter covers only silicon-centered radicals thatare directly or indirectly generated by the interaction of silicon-containing compoundswith light, thus excluding silyl radicals that are obtained through thermal methods.Thermal-decomposition methods for the production of silicon-centered radicals arewidely distributed, and constitute the subject of future review articles. This chapter alsocircumvents other silicon-based intermediates, such as silylenes, silenes, and radical ionsof silicon, which are also the subject of future review studies. Throughout the chapter itwill become apparent that the photochemical generation of silicon-centered radicals isoftenly accompanied by the production of other kinds of reactive silicon intermediates(silicon−centered biradicals, silylenes, silenes, etc.).