Molecular recognition in the gas phase ligand switching reactions of the proton bound dimer of sarcosine and glycylglycine.Part 35 of the series “Gas Phase Ion Chemistry of Biomolecules”. Part 34: A. K. Vrkic, and R. A. J. O’Hair, Gas phase reactions of trimethylborate with the [M-H]– ions of nucleotides and their non-covalent homo and heterodimer complexes, Aust. J. Chem., in press.Electronic supplementary information (ESI) available: heats of formation of adducts and PM3-optimized adduct structures. See http://www.rsc.org/suppdata/ob/b2/b209848b/

2003 ◽  
Vol 1 (4) ◽  
pp. 745-750 ◽  
Author(s):  
Richard A. J. O'Hair ◽  
Ana K. Vrkic
Keyword(s):  
Molecular Recognition ◽  
Gas Phase ◽  
Heats Of Formation ◽  
Supplementary Information ◽  
Ion Chemistry ◽  
Gas Phase Reactions ◽  
Gas Phase Ion Chemistry ◽  
Proton Bound Dimer ◽  
Gas Phase Ion

Gas-phase heteroaromatic substitution. 11. Electron transfer mechanism in the gas-phase acylation of simple five-membered heteroarenes

1991 ◽  
Vol 69 (4) ◽  
pp. 740-748 ◽  
Author(s):  
Antonello Filippi ◽  
Giorgio Occhiucci ◽  
Cinzia Sparapani ◽  
Maurizio Speranza
Keyword(s):  
Electron Transfer ◽  
Gas Phase ◽  
Reaction Products ◽  
Ion Chemistry ◽  
Gas Phase Reactions ◽  
Β Decay ◽  
Electron Transfer Mechanism ◽  
Gas Phase Ion Chemistry ◽  
Mass Spectrometric Evidence ◽  
Gas Phase Ion

The results of a study of the gas-phase reactions of unsaturated carbocations, such as the CH3CO+ ion from γ-radiolysis of CH3F/CO mixtures, and the C6H4TCO+ ion from the β-decay of 1,4-ditritiobenzene in the presence of CO, with pyrrole, N-methylpyrrole, furan, and thiophene, are reported. In all systems investigated, acylated heteroarenes represent the predominant reaction products, accompanied by the methylated derivatives in the CH3F/CO radiolytic mixtures, and by the phenylated ones in the 1,4-ditritiobenzene/CO decay samples. All substrates investigated are found to undergo predominant α substitution by both acetyl (88.6–98.4% (pyrrole); 90.8–98.7% (N-methylpyrrole); 97.2–98.9% (furan); 94.9–98.6% (thiophene)) and benzoyl cations (92.6–96.5% (pyrrole)) under all conditions. The predominant formation of the α-acylated pyrroles from both reactants (>88%), whose relative yields appear unaffected within the temperature interval from 303 to 383 K, indicates, in agreement with ancillary FT-ICR mass spectrometric evidence, that gas-phase acylation reactions toward simple five-membered heteroarenes proceed via a two-step substitution mechanism, involving a quasi-resonant single-electron transfer (SET) step followed by recombination of the ensuing radical – radical ion pair. By virtue of this entropy-favored mechanism, gaseous electrophiles with relatively high SCF STO-3G calculated LUMO energies such as CH3CO+ and C6H4TCO+ are effectively oriented toward the "soft" Cα sites of the selected heteroarenes, at variance with Klopman's Charge and Frontier Orbital Control predictions. The behavior of gaseous acylating reactants toward simple heteroarenes is discussed and compared with that of other gaseous electrophiles, whose reactivity appears instead in qualitative agreement with Klopman's model. Key words: gas-phase ion chemistry, electrophilic heteroaromatic substitution, nuclear decay and radiolysis, acylium ions, electron transfer.

ChemInform Abstract: Recent Gas Phase Ion Chemistry Studies

ChemInform ◽  
2010 ◽  
Vol 30 (20) ◽  
pp. no-no
Author(s):  
Nico M. M. Nibbering
Keyword(s):  
Gas Phase ◽  
Ion Chemistry ◽  
Gas Phase Ion Chemistry ◽  
Gas Phase Ion

Gas-Phase Ion Chemistry of Small Gold Cluster Anions

2010 ◽  
Vol 29 (13) ◽  
pp. 3001-3006 ◽  
Author(s):  
Robert F. Höckendorf ◽  
Yali Cao ◽  
Martin K. Beyer
Keyword(s):  
Gas Phase ◽  
Gold Cluster ◽  
Cluster Anions ◽  
Ion Chemistry ◽  
Gas Phase Ion Chemistry ◽  
Gas Phase Ion ◽  
Small Gold Cluster

Gas-phase ion chemistry of the propyne/ammonia and silane/propyne/ammonia systems

2004 ◽  
Vol 232 (2) ◽  
pp. 139-146 ◽  
Author(s):  
L. Operti ◽  
R. Rabezzana ◽  
F. Turco ◽  
G.A. Vaglio
Keyword(s):  
Gas Phase ◽  
Ion Chemistry ◽  
Gas Phase Ion Chemistry ◽  
Gas Phase Ion
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