Penning Ionization of Cyclopropanes by Collision with He*(2³S) Metastable Atoms

Abstract

The Penning ionization of cyclopropane (C 3 H 6 ), cyclopropylamine (C 3 H 5 NH 2 ), and cyanocyclopropane (C 3 H 5 -CN) upon collision with He*(2 3 S) metastable atoms was studied by collision energy resolved Penning ionization electron spectroscopy. Collision energy dependence of the partial ionization cross sections indicated that the interaction potentials are strongly anisotropic between He*(2 3 S) and the investigated cyclopropanes. In the studied energy range, the interaction potential was found to be attractive around the amino and cyano groups. A repulsive interaction potential was found around the carbon ring and hydrogen atoms for cyclopropane, and the order of the hardness was C 3 ring (out-of-plane direction) < hydrogen atoms < C 3 ring (in-plane direction). These are consistent with calculated interaction potential curves.

Penning Ionization of (NH2)2CX (X = O, S) with He*(23S) Metastable Atoms. Difference of Anisotropic Interaction around N, O, and S Atoms

“…In addition, it should be noted that geometry optimization was performed with ab initio calculation for H 2 CX...LiF (X = O, S), and n σ lone pair donation was found for the oxygen compound and n π lone pair donation was found for the sulfur compound. On the other hand, a strong attractive interaction was found for the lone pair n N orbital region of cyclopropylamine (C 3 H 5 NH 2 ) and nitriles. ,, In addition, to obtain CEDPICS of NCCN by collision with He*(2 3 S), a classical trajectory calculation was performed on the highly symmetric ( D ∞ h ) potential energy surface with attractive interaction around the N atoms …”

Two-Dimensional Penning Ionization Electron Spectroscopy of NNO, HCNO, and HNNN: Electronic Structure and the Interaction Potential with He*(23S) Metastable and Li(22S) Ground State Atoms

“…The most important questions we want to answer with a series of studies are the characteristics and anisotropy of the interaction potential, the effect of electronegativity, valence, and bonding of atoms on this, the interaction around chemical groups or bonds, and the influence of substituents on these. Previous CEDPICS 1,[6][7][8][9][10][11][12][13][14] and recent 2D-PIES 15,16 studies on various molecular targets have indicated that the interaction potential is anisotropic between molecules and He*(2 3 S) atoms and pointed out the importance of the chemical groups in describing the interaction. It has been observed that the interaction is repulsive around saturated hydrocarbons, alkyl groups, or CH bonds 1,[6][7][8][9][10]13,15,16 but attractive around the π region of unsaturated hydrocarbons, 7,8 heterocycles, 10 and CdO double bonds.…”

“…It has been observed that the interaction is repulsive around saturated hydrocarbons, alkyl groups, or CH bonds 1,[6][7][8][9][10]13,15,16 but attractive around the π region of unsaturated hydrocarbons, 7,8 heterocycles, 10 and CdO double bonds. 8 Studies of alcohols, 9,15 aldehides, 8 ethers, 9,11 amines, 12 isocyanates, 13 nitriles, 1,12,16 and isonitriles 1 have indicated that the interaction is attractive in the lone electron pair region of first-row nonmetal atoms (O, N, and C). There is relatively little known about the molecules containing heavier elements so far, and these studies have focused on organic chlorides and on sulfur compounds in comparison with the oxygen analogue.…”

Penning Ionization Electron Spectroscopic and Ab Initio Study of the Interaction and Ionization of HNCO and HNCS with He*(23S) Metastable and Li(22S) Ground State Atoms

“…20 eV. We have successfully applied the CERPIES and the recently developed 2D-PIES techniques to study the interaction between He*(2 3 S) and various organic molecules and interpreted the results in the frame of the molecular orbital picture. − It has been observed that the interaction is repulsive around saturated hydrocarbons, alkyl groups, or CH bonds, − ,,, but attractive around the π region of unsaturated hydrocarbons, , heterocycles, and CO double bonds . Studies of alcohols, , aldehides, ethers, , amines, isocyanates, nitriles, ,, and isonitriles, have indicated that the interaction is attractive in the lone electron pair region of first-row nonmetal atoms (O, N, and C).…”

“…We have successfully applied the CERPIES and the recently developed 2D-PIES techniques to study the interaction between He*(2 3 S) and various organic molecules and interpreted the results in the frame of the molecular orbital picture. − It has been observed that the interaction is repulsive around saturated hydrocarbons, alkyl groups, or CH bonds, − ,,, but attractive around the π region of unsaturated hydrocarbons, , heterocycles, and CO double bonds . Studies of alcohols, , aldehides, ethers, , amines, isocyanates, nitriles, ,, and isonitriles, have indicated that the interaction is attractive in the lone electron pair region of first-row nonmetal atoms (O, N, and C). According to the few studies on molecules containing heavier elements, which focus on organic chlorides and sulfur compounds, the interaction potential is attractive around the chlorine atom, , but in the case of the sulfur atom it is strongly dependent on the molecular environment: a very attractive potential was found in the sulfur lone pair region in alkyl thioethers and thioalcohols, but no special character (only weakly attractive or weakly repulsive) was found in the sulfur lone pair region of methyl thiocyanate, methyl isothiocyanate, and thiophene .…”