Mass-spectrometric Study on Ionization and Dissociation of Diethyl Ether by Electron Impact

A mass spectrometric study on ionization and dissociation of diethyl ether has been carried out. The M/e=31 ion is the most abundant among the ions produced by 75 eV. electron impact and the M/e=29, 59, 45 and 74 ions are abundant in this order next to M/e=31 ion. The appearance potential measurement of these ions leads to the following conclusion. The ions are formed by the removal of one of the lone pair electrons of the oxygen atom in the molecule. By considering the trivalent structure of O+ and by applying the bond energy additivity, which is adequate for hydrocarbons, to such an ionized dissociation process the producing processes of such ions can be satisfactorily revealed. The stabilization energy for the formation >C=O+- structure is obtained as 54 kcal./mol. by such a calculation.