Journalartikel

Jahr der Veröffentlichung: 2011

Seiten: 645-667

Zeitschrift: Collection of Czechoslovak Chemical Communications

Bandnummer: 76

Heftnummer: 6

DOI Link: https://doi.org/10.1135/cccc2011053

Verlag: Institute of Organic Chemistry & Biochemistry

Abstract: 

The principal purpose of this investigation is the
determination of the tunneling half-lives of the trans-HCSH → H₂CS
and the trans-HCSeH → H₂CSe unimolecular isomerization
reactions at temperatures close to 0 K. To aid these determinations, accurate
electronic structure computations were performed, with electron correlation treatments
as extensive as CCSDT(Q) and basis sets as large as aug-cc-pCV5Z, for the
isomers of [H,H,C,S] and [H,H,C,Se] on their lowest singlet surfaces and for
the appropriate transition states yielding structural data for key stationary
points characterizing the isomerization reactions. The computational results
were subjected to a focal-point analysis (FPA) that yields accurate relative
energies with uncertainty estimates. The tunneling half-lives were determined
by a simple Eckart-barrier approach and via the more sophisticated though still
one-dimensional Wentzel–Kramers–Brillouin (WKB) approximation. Only
stationary-point information is needed for the former while an intrinsic
reaction path (IRP) is necessary for the latter approach. Both protocols
suggest that, unlike for the parent hydroxymethylene (HCOH), at the low
temperatures of matrix isolation experiments no tunneling will be observable
for the trans-HCSH and trans-HCSeH systems.

Harvard-Zitierstil: Sarka, J., Csaszar, A. and Schreiner, P. (2011) Do the mercaptocarbene (H–C–S–H) and selenocarbene (H–C–Se–H) congeners of hydroxycarbene (H–C–O–H) undergo 1,2-H-tunneling?, Collection of Czechoslovak Chemical Communications, 76(6), pp. 645-667. https://doi.org/10.1135/cccc2011053

APA-Zitierstil: Sarka, J., Csaszar, A., & Schreiner, P. (2011). Do the mercaptocarbene (H–C–S–H) and selenocarbene (H–C–Se–H) congeners of hydroxycarbene (H–C–O–H) undergo 1,2-H-tunneling?. Collection of Czechoslovak Chemical Communications. 76(6), 645-667. https://doi.org/10.1135/cccc2011053