| abstract |
The invention relates to N-oxyl radicals of formula (I) wherein X represents S, NR5, O, SO or SO¿2?, and; R?1, R2, R3, R4, and R5¿, independent of one another, represent organic groups or; R?1 and R2¿ and/or R?3 and R4¿, together with the carbon atom that carries them, represent a ring comprised of at least 3 atoms. The N-oxyl radicals are suited for controlling radical polymerizations and for stabilizing ethylenically unsaturated monomers against unwanted polymerization. |