Mass spectrometric characterization of 4-oxopentanoic acid and gas-phase ion fragmentation mechanisms studied using a triple quadrupole and time-of-flight analyzer hybrid system and density functional theory

2008 ◽  
Vol 22 (14) ◽  
pp. 2269-2279 ◽  
Author(s):  
Basem Kanawati ◽  
Seweryn Joniec ◽  
Richard Winterhalter ◽  
Geert K. Moortgat
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Mass Spectrometric ◽  
Triple Quadrupole ◽  
Functional Theory ◽  
Ion Fragmentation ◽  
Fragmentation Mechanisms ◽  
Gas Phase Ion

scholarly journals Formation and reactions of the 1, 8-naphthyridine (napy) ligated geminally dimetallated phenyl complexes [(napy)Cu2(Ph)]+, [(napy)Ag2(Ph)]+ and [(napy)CuAg(Ph)]+

2019 ◽  
Vol 25 (1) ◽  
pp. 30-43 ◽  
Author(s):  
Qiuyan Jin ◽  
Jiaye Li ◽  
Alireza Ariafard ◽  
Allan J Canty ◽  
Richard AJ O’Hair
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Ion Trap ◽  
Density Functional Theory Calculations ◽  
Collision Induced Dissociation ◽  
Ion Trap Mass Spectrometry ◽  
Functional Theory ◽  
Organometallic Cations ◽  
Gas Phase Ion

Gas-phase ion trap mass spectrometry experiments and density functional theory calculations have been used to examine the routes to the formation of the 1,8-naphthyridine (napy) ligated geminally dimetallated phenyl complexes [(napy)Cu2(Ph)]+, [(napy)Ag2(Ph)]+ and [(napy)CuAg(Ph)]+ via extrusion of CO2 or SO2 under collision-induced dissociation conditions from their corresponding precursor complexes [(napy)Cu2(O2CPh)]+, [(napy)Ag2(O2CPh)]+, [(napy)CuAg(O2CPh)]+ and [(napy)Cu2(O2SPh)]+, [(napy)Ag2(O2SPh)]+, [(napy)CuAg(O2SPh)]+. Desulfination was found to be more facile than decarboxylation. Density functional theory calculations reveal that extrusion proceeds via two transition states: TS1 enables isomerization of the O, O-bridged benzoate to its O-bound form; TS2 involves extrusion of CO2 or SO2 with the concomitant formation of the organometallic cation and has the highest barrier. Of all the organometallic cations, only [(napy)Cu2(Ph)]+ reacts with water via hydrolysis to give [(napy)Cu2(OH)]+, consistent with density functional theory calculations which show that hydrolysis proceeds via the initial formation of the adduct [(napy)Cu2(Ph)(H2O)]+ which then proceeds via TS3 in which the coordinated H2O is deprotonated by the coordinated phenyl anion to give the product complex [(napy)Cu2(OH)(C6H6)]+, which then loses benzene.

scholarly journals Copper mediated decyano decarboxylative coupling of cyanoacetate ligands: Pesci versus Lewis acid mechanism

2015 ◽  
Vol 44 (19) ◽  
pp. 9230-9240 ◽  
Author(s):  
Jiawei Li ◽  
George N. Khairallah ◽  
Vincent Steinmetz ◽  
Philippe Maitre ◽  
Richard A. J. O'Hair
Keyword(s):  
Mass Spectrometry ◽  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Ion Trap ◽  
Functional Theory ◽  
Decomposition Reactions ◽  
Decarboxylative Coupling ◽  
Gas Phase Ion ◽  
Sequential Decomposition

A combination of gas-phase ion trap multistage mass spectrometry (MSn) experiments and density functional theory (DFT) calculations have been used to examine the mechanisms of the sequential decomposition reactions of copper cyanoacetate anions, [(NCCH2CO2)2Cu]−.

Molecular structure and tautomers of [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin

2013 ◽  
Vol 17 (03) ◽  
pp. 220-228 ◽  
Author(s):  
Yuriy A. Zhabanov ◽  
Alexander V. Zakharov ◽  
Sergei A. Shlykov ◽  
Olga N. Trukhina ◽  
Elena A. Danilova ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Equilibrium Structure ◽  
Mass Spectrometric ◽  
Basis Sets ◽  
Functional Theory ◽  
Mass Spectrometric Experiment

The gas-phase molecular structure of the unsubstituted [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin (C30H15N15S3) has been studied by a synchronous gas electron diffraction and mass spectrometric experiment and density functional theory calculations using the B3LYP hybrid method and cc-pVTZ basis sets. The molecule has an equilibrium structure of D 3h symmetry with a planar macrocycle and the thiadiazole rings oriented in such a way that the sulfur atoms point outwards from the inner cavity. Tautomers of this compound have been studied by DFT computations.

Graph theory-based reaction pathway searches and DFT calculations for the mechanism studies of free radical-initiated peptide sequencing mass spectrometry (FRIPS MS): a model gas-phase reaction of GGR tri-peptide

2020 ◽  
Vol 22 (9) ◽  
pp. 5057-5069 ◽  
Author(s):  
Jae-ung Lee ◽  
Yeonjoon Kim ◽  
Woo Youn Kim ◽  
Han Bin Oh
Keyword(s):  
Graph Theory ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Reaction Pathway ◽  
Peptide Sequencing ◽  
Phase Reaction ◽  
Functional Theory ◽  
Fragmentation Mechanisms ◽  
Gas Phase Fragmentation

A new approach for elucidating gas-phase fragmentation mechanisms is proposed: graph theory-based reaction pathway searches (ACE-Reaction program) and density functional theory (DFT) calculations.

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