Gas-phase fragmentation of half- and first-generation polyamidoamine dendrimers by electrospray mass spectrometry using a quadrupole ion trap

2008 ◽  
Vol 22 (3) ◽  
pp. 363-372 ◽  
Author(s):  
Thomas J.-C. Vincent ◽  
Romain Dolé ◽  
Catherine M. Lange
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Electrospray Mass Spectrometry ◽  
First Generation ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Polyamidoamine Dendrimers ◽  
Gas Phase Fragmentation

scholarly journals A new charge-tagged proline-based organocatalyst for mechanistic studies using electrospray mass spectrometry

2014 ◽  
Vol 10 ◽  
pp. 2027-2037 ◽  
Author(s):  
J Alexander Willms ◽  
Rita Beel ◽  
Martin L Schmidt ◽  
Christian Mundt ◽  
Marianne Engeser
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Electrospray Mass Spectrometry ◽  
Temporal Evolution ◽  
Mechanistic Studies ◽  
Catalytic Center ◽  
Enamine Catalysis ◽  
Esi Mass Spectrometry ◽  
Catalyzed Reactions ◽  
Gas Phase Fragmentation

A new 4-hydroxy-L-proline derivative with a charged 1-ethylpyridinium-4-phenoxy substituent has been synthesized with the aim of facilitating mechanistic studies of proline-catalyzed reactions by ESI mass spectrometry. The charged residue ensures a strongly enhanced ESI response compared to neutral unmodified proline. The connection by a rigid linker fixes the position of the charge tag far away from the catalytic center in order to avoid unwanted interactions. The use of a charged catalyst leads to significantly enhanced ESI signal abundances for every catalyst-derived species which are the ones of highest interest present in a reacting solution. The new charged proline catalyst has been tested in the direct asymmetric inverse aldol reaction between aldehydes and diethyl ketomalonate. Two intermediates in accordance with the List–Houk mechanism for enamine catalysis have been detected and characterized by gas-phase fragmentation. In addition, their temporal evolution has been followed using a microreactor continuous-flow technique.

Electrospray ionization mass spectrometry of the cerium(III)-phosphomolybdate complex (NH4)11Ce(PMo11O39)2

2010 ◽  
Vol 1264 ◽  
Author(s):  
Travis Henry Bray ◽  
Roy Copping ◽  
David K. Shuh ◽  
John Gibson
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Gas Phase ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Collision Induced Dissociation ◽  
Ion Trap Mass Spectrometry ◽  
Ionization Mass ◽  
Naturally Occurring ◽  
Gas Phase Ions

AbstractElectrospray ionization quadrupole ion trap mass spectrometry of the ammonium lanthanide(III) phosphomolybdate complex (NH4)11Ce(III)(PMo11O39)2 has been conducted revealing the Ce-POM complexes H2Ce(III)P2Mo22O753- and Ce(III)PMo11O382- as the primary Ce species in 10 mM solutions. From the complex isotopic fingerprints produced through the assembly of multiple molybdenum atoms, a transition metal with seven naturally occurring isotopes, the identities of larger ions were confirmed via successive collision induced dissociation (CID) studies of the gas phase ions. The result of these CID studies was the production of smaller ions with reduced molybdenum content, allowing for comparison between calculated and experimental isotopic distributions. CID studies also provided insights into favored fragmentation pathways. These studies provide a basis to explore speciation and ESI behavior of actinide cluster complexes.

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