The condensation of trimethylsilylium with water and the proton affinity of trimethylsilanol

1986 ◽  
Vol 64 (3) ◽  
pp. 575-576 ◽  
Author(s):  
John A. Stone ◽  
Anastasia C. M. Wojtyniak ◽  
Willum Wytenburg
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Proton Affinity ◽  
Enthalpy Change ◽  
Tert Butanol

The proton affinity (PA) of trimethylsilanol has been determined by high pressure mass spectrometry from the enthalpy change for the reaction [Formula: see text]. ΔH0 = −30.1 ± 1.9 kcal mol−1 giving PA (Me3SiOH) = 183.7 kcal mol−1. This latter value is 10 kcal mol−1 less than that of the carbon analogue, tert-butanol.

A comparison of the relative binding energies of H+ and NO+ to aromatic and haloaromatic bases by high pressure mass spectrometry

1982 ◽  
Vol 60 (7) ◽  
pp. 910-915 ◽  
Author(s):  
John A. Stone ◽  
Dena E. Splinter ◽  
Soon Yau Kong
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Proton Affinity ◽  
Marked Effect ◽  
Ion Source ◽  
Binding Energies ◽  
Absolute Value ◽  
Pulsed Electron Beam ◽  
Relative Binding ◽  
Benzene Toluene

Proton transfer equilibria [Formula: see text] and NO+ transfer equilibria [Formula: see text] have been studied for the following bases B, benzene, toluene, o-, m-, and p-xylene. NO+ transfer equilibria for fluoro- and chlorobenzene have also been studied. Pulsed electron beam, high-pressure ion source mass spectrometry has been used to obtain the equilibrium constant K and hence the free energy changes ΔG0 and from van't Hoff plots, ΔH0 and ΔS0. Entropy changes are in general much smaller for NO+ transfer than for H+ transfer but the magnitude of the changes in the proton affinity and NO+ affinity of toluene caused by a fluorine substituent is about the same, even though the absolute value of the proton affinity is greater by a factor of 4. The position of the F substituent on toluene has a marked effect on proton affinity but no effect on NO+ affinity. The latter appears to be responsive only to the inductive effect.

The proton affinity of triethylsilanol obtained by proton transfer equilibrium measurements using a high pressure mass spectrometer

1988 ◽  
Vol 66 (5) ◽  
pp. 1288-1292 ◽  
Author(s):  
Xiaoping Li ◽  
John A. Stone
Keyword(s):  
High Pressure ◽  
Proton Transfer ◽  
Proton Affinity ◽  
Mass Spectrometer ◽  
Enthalpy Change ◽  
A Value

The proton affinity (PA) of triethylsilanol has been determined by equilibrium proton transfer measurements using a high pressure mass spectrometer. The reference bases were naphthalene and m-xylene which have the required low affinities for trialkylsilylium. van't Hoff plots were used to obtain PA((C2H5)3SiOH) = 197.9 ± 0.4 kcal mol−1•This value is used to recommend that. PA((CH3)3SiOH) ≈ 192 kcal mol−1•(C2H5)3Si+ has been produced by the protonation of (C2H5)4Si and the enthalpy change for the reaction [Formula: see text] has been determined to be 32 ± 1 kcal mol−1 which gives [Formula: see text]((C2H5)3Si+) = 135 kcal mol−1•A value of ~ 141 kcal mol−1 is recommended for [Formula: see text].

scholarly journals Ethoxylated Butoxyethanol-BADGE Adducts—New Potential Migrants from Epoxy Resin Can Coating Material

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3682
Author(s):  
Monika Beszterda ◽  
Małgorzata Kasperkowiak ◽  
Magdalena Frańska ◽  
Sandra Jęziołowska ◽  
Rafał Frański
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Epoxy Resin ◽  
Diglycidyl Ether ◽  
Ionization Mass ◽  
Coating Materials ◽  
Oxyethylene Unit ◽  
Bisphenol A Diglycidyl Ether ◽  
Product Ions

The acetonitrile extracts of can-coating materials have been analyzed by using high-pressure liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). On the basis of detected ions [M + H]+, [M + NH4]+, [M + Na]+ and product ions, the ethoxylated butoxyethanol-bisphenol A diglycidyl ether adducts were identified in two of the analyzed extracts. Although the oxyethylene unit-containing compounds are widely used for the production of different kinds of materials, the ethoxylated species have not been earlier detected in epoxy resin can-coatings.

scholarly journals Fast log P determination by ultra-high-pressure liquid chromatography coupled with UV and mass spectrometry detections

2009 ◽  
Vol 394 (7) ◽  
pp. 1919-1930 ◽  
Author(s):  
Yveline Henchoz ◽  
Davy Guillarme ◽  
Sophie Martel ◽  
Serge Rudaz ◽  
Jean-Luc Veuthey ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
Log P ◽  
Ultra High Pressure
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