Ortho effects in organic molecules on electron impact. Part 16. Novel oxygen transfers from the nitro group to acetylenic carbons in 2-nitrodiphenylacetylenes

Oxygen transfers to both acetylene carbons are noticed in parallel fragmentation pathways during the electron impact induced decompositions of 2-nitrodiphenylacetylene. The oxygen transfer to β-acetylenic carbon leads to the most abundant ion corresponding to benzoyl cation while transfer to the α-acetylenic carbon affords less intense fragments corresponding to M? OH]⁺, M? CO]^{+ ˙} and M? CO₂]^{+ ˙}. The proposed fragmentation pathways and ion structures are supported by high-resolution data, linked-scan spectra and chemical substitution.