Photoionization mass spectrometric studies of the isomeric transient species CD2OH and CD3O

Both CD2OH and CD3O were prepared in situ by the reaction of F atoms with CD3OH, and studied by photoionization mass spectrometry. The adiabatic ionization potential (I.P.) of CD2OH was found to be 7.540±0.006 eV, in good agreement with the photoelectron spectroscopy (PES) value, 7.55±0.01 eV. However, the adiabatic I.P. of CD3O was determined to be 10.726±0.008 eV, in marked contrast to the PES value for CH3O, 7.37±0.03 eV, but in the expected range based on reported values of ΔH0f(CH3O+) and ΔH0f(CH3O). From selected values of ΔH0f0(CH2OH+) ≤172.0±0.7 kcal/mol and ΔH0f0(CH3O) =5.9±1.0 kcal/mol, we deduce ΔH0f0(CH2OH) ≤−2.1±0.7 kcal/mol and ΔH0f0(CH3O+) =253.1±1.0 kcal/mol.