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Ionization

University of Wollongong

Publication Year

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Full-Text Articles in Physical Sciences and Mathematics

Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom Jan 2012

Comment On The Ionization Energy Of B2f4, Bun Chan, Adam J. Trevitt, Stephen J. Blanksby, Leo Radom

Faculty of Science - Papers (Archive)

The Gn test sets(1) of accurate (uncertainty ≤ 1 kcal mol–1 ≈ 4 kJ mol–1) experimental data are widely employed in the development and assessment of quantum chemistry procedures. However, while all the data in the Gn sets nominally carry a sub-kcal mol–1 uncertainty, several of the experimental values show uncharacteristically large discrepancies when compared with values determined by high-level theoretical calculations. One of these questionable values is the adiabatic ionization energy (IE) of B2F4, for which the theoretical values calculated, for example, with the high-level G2 (1133.9, kJ mol–1),(1b) G3 (1135.4 kJ mol–1),(2) and G4 (1127.2 kJ mol–1)(3) procedures …


Detection Of Al(Iii) And Ga(Iii) Complexes With Morin By Electrospray Ionization Mass Spectrometry, John B. Bremner, Larry A. Hick, Jody Morgan, Saowanee Rattanaphani, Vichitr Rattanaphani, C Septhum Jan 2007

Detection Of Al(Iii) And Ga(Iii) Complexes With Morin By Electrospray Ionization Mass Spectrometry, John B. Bremner, Larry A. Hick, Jody Morgan, Saowanee Rattanaphani, Vichitr Rattanaphani, C Septhum

Faculty of Science - Papers (Archive)

The Al(III) and Ga(III) complexes formed by morin (M) in aqueous solution were investigated by means of electrospray ionization mass spectrometry (ESI-MS). In the full scan mass spectra, Al:M showed 1:2 and 2:3 stoichiometric ratios. When (S)-N-acetylserine methyl ester (Ser), as a partial mimic of the serine residue in silk, was added to Al:M and Ga:M complexes in aqueous solution, the mass spectra of Ser:Al:M showed 1:1:1 and 1:1:2 stoichiometric ratios. The patterns of the mass spectra of Ga:M and Ser:Ga:M complexes were similar to those for the corresponding Al(III) complexes. Calculated heats of formation of potential structures of the …


Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon Jan 2007

Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon

Faculty of Science - Papers (Archive)

Changes in protein conformation are thought to alter charge state distributions observed in electrospray ionization mass spectra (ESI-MS) of proteins. In most cases, this has been demonstrated by unfolding proteins through acidification of the solution. This methodology changes the properties of the solvent so that changes in the ESI-MS charge envelopes from conformational changes are difficult to separate from the effects of changing solvent on the ionization process. A novel strategy is presented enabling comparison of ESI mass spectra of a folded and partially unfolded protein of the same amino acid sequence subjected to the same experimental protocols and conditions. …