The trimethylsilyl substituent effect on the reactivity of silanes. Structural correlations between silyl radicals and their parent silanes
作者:C. Chatgilialoglu、A. Guerrini、M. Lucarini
DOI:10.1021/jo00038a031
日期:1992.6
Good linear correlations exist both between the bond dissociation energy of an Si-H bond and the corresponding SiH stretching frequency and between the Si-29 hyperfine splitting of a silicon-centered radical and J(Si-29-H) for the corresponding silane, when the successive substitution at the Si-H function takes place inside a family, i.e., (Me3Si)3-nSi(H)Men, n = 0-3. Explanations for these phenomena are advanced. Such structural correlations allow the characterization of (Me3Si)2Si(H)Me as a radical-based reducing agent with low hydrogen-donating abilities. Rate constants for the reaction of primary alkyl radicals with (Me3Si)2Si(H)Me have been measured over a range of temperatures by using competing unimolecular radical reactions as timing devices. The radical trapping abilities of this silane and other common radical-based reducing agents are compared.