Addition of organometallic radicals to organic substrates. A useful spin-trap reagent for Group 4 radicals

Abstract

Silyl, germyl, and stannyl radicals add to the carbon–nitrogen double bond of N-dicyanomethyleneaniline (1) giving Ar–NC(CN)₂+ R₃M˙→ Ar–N(MR₃)–Ċ(CN)₂ persistent paramagnetic species detected by e.s.r. spectroscopy. Compounds (1) are photostabile and do not give observable paramagnetic adducts with carbon- or oxygen-centred radicals; they can therefore be regarded as suitable ‘spin-trap’ reagents for group 4B radicals, not easily scavenged by nitroso-derivatives.