A Study by He I Photoelectron Spectroscopy of Monomeric Nitrosomethane, the Cis and Trans Dimers, and Formaldoxime

Article abstract of DOI:10.1021/j100215a017

A combination of in situ He I photoelectron and quadrupole mass spectroscopy has been used to study monomeric nitrosomethane, the cis and trans isomers, and formaldoxime.In contrast to earlier results it is shown that cis-(CH3NO)2 sequentially gives CH2=NOH and CH3NO upon vaporization.A photoelectron spectrum of the cis dimer was not observed.In addition, a previous spectrum of "monomeric" CH3NO is shown to belong to the trans dimer.The assignments of the measured ionization potentials for these species are supported by semiempirical HAM/3 results.A breakdown of Koopmans' theorem is confirmed for CH3NO by a calculation involving perturbation corrections.