ESR Spectra of Some Allene Radicals in Low-Temperature Matrices

ESR spectra of the radicals of allene (1,2-propadiene) derivatives generated by 60Co γ-ray irradiation in halocarbon matrices have been observed at low temperatures. The geometrical structures of the radicals have been determined from the experimental ESR spectra and with the aid of semiempirical MO calculations invoking the UHF-AM1 and UHF-MNDO methods. After exposure of the allene derivatives to 60Co γ-ray in some halocarbon matrices at 77 K, the temperature raising gave rise to neutral radicals such as allylic and/or deprotonation-type radicals; these thermal reactions have been investigated in detail.

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