Isotope effect in the cross sections of negative ion formation by methanol molecules

Formation of negative ions by CH3OH, CH3OD, CD3OH and CD3OD molecules is studied. Resonances at 6.2; 7.8; 10.5 and 12.8 eV are interpreted as electron-excited resonances related with electron excitation from the occupied molecular orbitals (MO) to one and the same vacant MO, with a hole on the first, second, third and fifth occupied MO. In the resonance at 3 eV a direct isotopic effect sufficient by the value, is observed in case of (M-H)-ions formation. Reverse isotopic effect in the cross section of (M-D)-ion formation from CH3OD is detected in the resonance at electron energy of 6.2 eV. Similar effect is observed in case of O- ion formation from CD3OH in the resenance at 10.5 eV. The given effect is explained by valent vibration mixing in molecular negative ion