4Pb72

Collision energy dependencies of partial ionization cross sections of formamide and its methyl group substituted compounds by He*(2³S)

Yukio Osada, Kohji Okamura, Hideo Yamakado, and Koichi Ohno
(Department of Chemistry, Graduate School of Science, Tohoku University)

We have measured collision energy dependencies of partial ionization cross sections (CEDPICS) of Penning ionization electron spectra (PIES) for many compounds, and obtained information on interactions between metastable atoms and target molecules. In the present study, we have taken formamide and its methyl group-substituted derivatives, N-methyl formamide and N,N-dimethyl formamide for samples. New information on assignments of ultraviolet photoelectron spectra (UPS) and interactions between metastable atoms and amides has been obtained on the basis of UPS, PIES, and CEDPICS. For amines studied previously attractive-type interactions have been found around the nitrogen non-bonding orbitals which extends outside molecular surfaces. On the other hand, the attractive interactions of the amide molecules were found to be weak. This is supported by the calculation of interaction potentials. The oxygen atom in ketone groups, have shown very strong attractive-type interactions. It was found that the results of the amide are similar to previous results.