Radiation induced transformations of benzaldehydes carrying formyl-, nitro- or nitroso-substituents in the ortho position

Abstract

Transformations induced by X-irradiation of o-phthalaldehyde (1), o-nitrobenzaldehyde (2), and o-nitrosobenzaldehyde (3) isolated in argon matrices are described. It is shown that the formyl hydrogens in 1, 2 and 3 spontaneously migrate to the respective o-substituents upon ionization. The resulting radical cations are characterized mainly by the ketene and OH stretching bands in their IR spectra.

In all cases, X-irradiation led also to the formation of substantial amounts of the neutral tautomers as well as other products in the case of 2 and 3. These are thought to arise by way of the corresponding radical cations which are reneutralized by scavenging some of the electrons ejected from the matrix material upon X-irradiation.