Investigation of possible isomerisation reactions in benzene, iodobenzene, and phenol upon electron impact

Abstract
Complete randomisation of the carbon and hydrogen atoms, before fragmentation, in the molecular ion of benzene, and of the hydrogen atoms with respect to all carbon atoms in the ion C6H5 + derived from iodobenzene, has been demonstrated in the mass spectrometer by suitable labelling experiments. However, study of the decomposition of the molecular ion of phenol by loss of carbon monoxide indicates that the functionalised carbon atom undergoes negligible randomisation.