Intermolecular proton transfer reactions in the laser mass spectrometry of organic acids

1986 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Cass D. Parker ◽  
David M. Hercules
Keyword(s):  
Mass Spectrometry ◽  
Proton Transfer ◽  
Organic Acids ◽  
Transfer Reactions ◽  
Laser Mass Spectrometry ◽  
Intermolecular Proton Transfer ◽  
Proton Transfer Reactions

Effect of electronic excitation to intermolecular proton transfer in bulk nitromethane: Tuned parameter SCC-DFTB and first principles study

2015 ◽  
Vol 14 (02) ◽  
pp. 1550013 ◽  
Author(s):  
Feng Guo ◽  
Hong Zhang ◽  
Chao-Yang Zhang ◽  
Xin-Lu Cheng ◽  
Hai-Quan Hu
Keyword(s):  
Proton Transfer ◽  
First Principles ◽  
Density Functional ◽  
Tight Binding ◽  
Transfer Reactions ◽  
Singlet Ground State ◽  
Functional Theory ◽  
Intermolecular Proton Transfer ◽  
Proton Transfer Reactions ◽  
Dynamics Simulations

To understand the reaction mechanism involving hydrogen transfers through hydrogen-bond bridge, we carried out both Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) calculations of bulk nitromethane and Density Functional Theory (DFT) calculations of singlet ground state/triplet excited state molecular nitromethane using B3LYP functional. Firstly, we tuned the repulsive parameters of the SCC-DFTB method for nitromethane with dataset calculated from DFT at B3LYP/6-311g level. The molecular dynamics simulations are carried out with tuned parameters to get the dynamical properties of the bulk nitromethane, and the static calculations are intended to give energy profile of the reaction process. These calculations indicate the excitation of nitromethane molecule making the proton transfer reactions possible, and lowering the reaction barrier.

Flame Ionization of Silicon, Germanium and Tin

1985 ◽  
Vol 38 (3) ◽  
pp. 347 ◽  
Author(s):  
NS Ham ◽  
T McAllister
Keyword(s):  
Mass Spectrometry ◽  
Proton Transfer ◽  
Charge Exchange ◽  
Silicon Germanium ◽  
Diffusion Flames ◽  
Transfer Reactions ◽  
Proton Affinities ◽  
Atomic Ions ◽  
Flame Ionization ◽  
Proton Transfer Reactions

.When compounds of Si , Ge and Sn are added to 2/C6H6 diffusion flames, ions characteristic of the elements are detected in the burnt gases by mass spectrometry. The ions, which are attributed to charge exchange and proton transfer reactions of H3O+, may be divided into three categories, atomic ions, protonated monoxides and protonated oxyacids . Sn gives atomic ions and protonated monoxides, a similar result to Pb , but neither Si nor Ge give atomic ions. This may be a consequence of the lack of Si and Ge atoms in the burnt gases. Ge and Sn give a protonated monoxide, but Si does not. This observation leads to the suggestion that proton affinities of the Group 4a monoxides are in the order CO, SiO < H2O < GeO , SnO , PbO. Protonated silicic and germanic acids are observed in the burnt gases of Si - and Ge -containing flames, but no oxyacids were observed in Sn -or Pb -containing flames. This indicates that the proton affinities of both acids are greater than that of H2O.

Substituent and solvent effects on organic acids: an electrostatic theory

1976 ◽  
Vol 54 (8) ◽  
pp. 1296-1299 ◽  
Author(s):  
Takeki Matsui ◽  
Loren G. Hepler
Keyword(s):  
Proton Transfer ◽  
Organic Acids ◽  
Gas Phase ◽  
Solvent Effects ◽  
Transfer Reactions ◽  
Electrostatic Model ◽  
Environmental Models ◽  
Gas Phase Acidity ◽  
Proton Transfer Reactions ◽  
Electrostatic Theory

We have used an electrostatic model as basis for derived equations to represent the effects of substituents and solvents on the thermodynamics of proton transfer reactions. Equations derived in this manner are related to those based on earlier 'internal-environmental' models and are also discussed in relation to recent gas phase acidity work.

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