Mass spectrometric study of negative ions from unsaturated carbonyls

Negative ion formation from some unsaturated carbonyl derivatives is investigated as a function of electron energy by using a monochromatic (0.2 eV) and low-energy (0-10 eV) electron beam and a mass spectrometer. Negative ions at low energies are formed via a dissociative attachment process. Appearance potentials of certain negative ions can be correlated with the electron-releasing or -withdrawing power of the substituents and/or with bond strengths. For example, the appearance potentials of C6H5CO" and C2H3CO" both shift to higher energies as the C-X bond is weakened through the electron-withdrawing power of X in the order X = Cl > OH > H > CH3. The appearance potentials are also used to estimate the bond dissociation energies not available in the literature. Accordingly, C6H5-COX bond energies can be calculated as 3.9, 3.7, and 3.0 eV for X = H, OH, and Cl, respectively, by using the measured appearance potentials of C6H5" ion from these molecules and the published bond energy of 4.033 eV for acetophenone (X = CH3).
Journal of Physical Chemistry


Mass spectrometric study of negative ions from acetyl derivatives
Hacaloğlu, Jale; Suzer, S. (1989-01-01)
A mass spectrometic technique capable of producing a low-energy and nearly monochromatic (fwhm ~ 0.2 eV) electron beam is developed and used to study the negative ions from five different acetyl derivatives CH3COX (X = Cl, C6H5, NH2, CH3, and H) at very low energies (0-10 eV). Negative ions are mainly produced by dissociative attachment and show resonance-like structures. To measure the excess energy imparted to the ions during ionization, a time-of-flight technique is applied. An ion with composition C2H30...
Bosonic helium clusters doped by alkali metal cations: interaction forces and analysis of their most stable structures
Marinetti, F.; Coccia, E.; Bodo, E.; Gianturco, F. A.; Yurtsever, E.; Yurtsever, M.; Yıldırım, Erol (Springer Science and Business Media LLC, 2007-07-01)
Ab initio potentials are computed for alkali metal cationic partners interacting with He-4 and an overall many-body potential is constructed for each of the ionic dopants in helium clusters. The structures are then obtained via a genetic algorithm approach and results compared with Basin-Hopping Monte Carlo simulations. The classical arrangements are analyzed and quantum effects discussed in comparison with what has been found with Diffusion Monte Carlo calculations. Further corrections to the classical pic...
GOKAGAC, G; ISCI, H; MASON, WR (American Chemical Society (ACS), 1992-05-27)
Electronic absorption and 7-T magnetic circular dichroism (MCD) spectra in the UV-visible region are reported for the binuclear diplatinum(III) ions: Pt2(SO4)4X2n-, n = 2, X = H2O, NH3; n = 4, X = Cl-, Br-, OH-. Pt2(HPO4)4X2n-, n = 2, X = H2O, Me2S; n = 4, X = Cl-, Br-. Both the absorption spectra and the MCD spectra for complexes with the same axial ligand X are similar for oxo-bridging SO42- or HPO42-. However, the MCD spectra show marked differences depending upon the nature of the X ligand. The mos...
Electrochemistry of nickel(II) complexes with N,N'-bis(3,5-di-tert-butylsalicylidene)polymethylenediamines
Ozalp-Yaman, S; Kasumov, VT; Önal, Ahmet Muhtar (Elsevier BV, 2005-10-03)
The electrochemical oxidation of several N,N'-polymethylenebis(3,5-di-tert- butylsalicylaldiminato)nickel(II) complexes, Ni(L-x), has been studied by cyclic voltammetry and in situ UV-Vis spectroscopy in DMF Cyclic voltammograms of Ni(L-x) (x = 1-4) complexes displayed two-step oxidation processes under nitrogen gas atmosphere. The first oxidation peak potentials of all the Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. EPR spectr...
Katırcıoğlu, Şenay (Elsevier BV, 1991-08-09)
The structural stability and energetics of As, Sb and Bi microclusters having 3-7 atoms have been investigated by using a recently developed empirical many-body potential energy function (PEF), which comprises two- and three-body atomic interactions. The PEF satisfies both bulk cohesive energy per atom and bulk structural stability exactly. It has been found that the most stable structures of As3, Sb3 and Sb4 microclusters are in linear form with D-infinity-h symmetry, Bi7 is in hexagonal pyramid form with ...
Citation Formats
J. Hacaloğlu, A. Gökmen, and H. Baumgartel, “Mass spectrometric study of negative ions from unsaturated carbonyls,” Journal of Physical Chemistry, pp. 7095–7098, 1989, Accessed: 00, 2020. [Online]. Available: