Journalartikel

Jahr der Veröffentlichung: 2018

Seiten: 1488-1495

Zeitschrift: The Journal of Physical Chemistry A

Bandnummer: 122

Heftnummer: 5

DOI Link: https://doi.org/10.1021/acs.jpca.7b12118

Verlag: American Chemical Society

Abstract: 

Although frequently employed, heavy atom kinetic isotope effects (KIE)
have not been reported for quantum mechanical tunneling reactions. Here
we examine the secondary KIE through ¹³C-substitution of the carbene atom in methylhydroxycarbene (H₃C–C̈–OH) in its [1,2]H-tunneling shift reaction to acetaldehyde (H₃C–CHO).
Our study employs matrix-isolation IR spectroscopy in various inert
gases and quantum chemical computations. Depending on the choice of the
matrix host gas, the KIE varies within a range of 1.0 in xenon to 1.4 in
neon. A KIE of 1.1 was computed using the Wentzel−Kramers−Brillouin
(WKB) CVT/SCT, and instanton approaches for the gas phase at the
B3LYP/cc-pVTZ level of theory. Computations with explicit consideration
of the noble gas environment indicate that the surrounding atoms
influence the tunneling reaction barrier height and width. The tunneling
half-lives computed with the WKB approach are in good agreement with
the experimental results in the different noble gases.

Harvard-Zitierstil: Eckhardt, A., Gerbig, D. and Schreiner, P. (2018) Heavy Atom Secondary Kinetic Isotope Effect on H-Tunneling, The Journal of Physical Chemistry A, 122(5), pp. 1488-1495. https://doi.org/10.1021/acs.jpca.7b12118

APA-Zitierstil: Eckhardt, A., Gerbig, D., & Schreiner, P. (2018). Heavy Atom Secondary Kinetic Isotope Effect on H-Tunneling. The Journal of Physical Chemistry A. 122(5), 1488-1495. https://doi.org/10.1021/acs.jpca.7b12118