Structures and Unimolecular Reactivity of Gas-Phase[Zn(Proline-H)]+and [Zn(Proline-H)(H2O)]+.
In: Journal of Physical Chemistry B, Jg. 117 (2013-07-18), Heft 28, S. 8447-8456
academicJournal
Zugriff:
A combinationof IRMPD spectroscopy, collision-induced dissociation,deuterium isotopic substitution, and computational chemistry was usedto determine the structure and unimolecular chemistry of [Zn(Pro-H)]+and the singly hydrated complex in the gas phase. Five competingdissociation channels were observed: loss of H2O, CO, CO2, and HCOOH and the main fragmentation pathway, loss of neutralZn. By comparing the IRMPD spectrum with the predicted IR spectraof the lowest energy structures, it was confirmed that [Zn(Pro-H)]+complex is deprotonated at the amine moiety, and a hydrogenfrom either C2 or C5 migrated to Zn2+. In this H-type complex,ZnH+was chelated between the amine nitrogen and the carbonyloxygen. Calculations of the potential energy surface revealed thatthe loss of neutral zinc is energetically more favorable than theloss of dehydrogenated proline leading to ZnH+product.Furthermore, calculations on all five primary decomposition routes,all beginning with the lowest energy structure, revealed that lossof Zn has the lowest energy requirement, consistent with it beingthe most abundant product of unimolecular dissociation following collisionalor IR multiphoton activation. For the singly hydrated complex, [Zn(Pro-H)(H2O)]+, IRMPD spectroscopy confirms a structure withwater added to the H-type structure and intramolecularly hydrogenbonded to the deprotonated amine site. This structure is not the lowest-energy[Zn(Pro-H)(H2O)]+isomer, but it is the onewhere water is added to the lowest energy [Zn(Pro-H)]+isomer. [ABSTRACT FROM AUTHOR]
Titel: |
Structures and Unimolecular Reactivity of Gas-Phase[Zn(Proline-H)]+and [Zn(Proline-H)(H2O)]+.
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Autor/in / Beteiligte Person: | Gholami, Ameneh ; Fridgen, Travis D. |
Zeitschrift: | Journal of Physical Chemistry B, Jg. 117 (2013-07-18), Heft 28, S. 8447-8456 |
Veröffentlichung: | 2013 |
Medientyp: | academicJournal |
ISSN: | 1520-6106 (print) |
DOI: | 10.1021/jp404697g |
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