Free Radicals by Mass Spectrometry: Xxii. Primary Decomposition Steps in the Mercury-Photosensitized Decomposition of Methanol and Dimethyl Ether

The Hg 3P1 photosensitized decomposition of methanol at low pressures proceeds mainly by a dissociation into CH3O radicals and H atoms. No formation of CH2OH radicals is observed. A subsidiary reaction to form CH3 and OH may also be a primary step. Formation of CH2OH radicals at higher pressures is attributed to an abstraction reaction of CH3O with CH3OH.Two primary modes of dissociation are found to occur for dimethyl ether:[Formula: see text]The relative probabilities of occurrence at low pressures are ∼45% and ∼50%, respectively. The possibility that the second reaction proceeds by formation of an excited molecule is discussed.