Unstable intermediates. Part CXXV. H(R)CN radicals in γ-irradiated cyanoacetic acid and acidic solutions of methyl cyanide

Abstract

Exposure of cyanoacetic acid to ⁶⁰Co γ-rays at 77 K gave radicals whose e.s.r. spectra were characteristic of H₂ĊCN and H(CH₂CO₂H)CN radicals. The latter had a(¹H)= 85 G, a_∥(¹⁴N)= 32 G, a_⊥(¹⁴N)= 0 ± 2 G, and a(¹H)(CH₂)= 3 G. Similarly, aqueous sulphuric or acetic acid glasses containing methyl cyanide gave, amongst several radicals, H(Me)CN, with similar magnetic parameters. These results were supported by studies of CD₃CN in D₂SO₄–D₂O. Possible mechanisms are discussed.