Journalartikel

Jahr der Veröffentlichung: 2000

Seiten: 2239-2244

Zeitschrift: Physical Chemistry Chemical Physics

Bandnummer: 2

Heftnummer: 10

ISSN: 1463-9076

DOI Link: https://doi.org/10.1039/b000597p

Verlag: Royal Society of Chemistry

Abstract: 
The kinetic stability of SH4 was investigated theoretically with the coupled cluster ansatz. The two possible modes of decomposition into SH2 and H-2 through either a C-2v or a C-1 transition structure (TS) were investigated using intrinsic reaction coordinate (IRC) computations; orbital interactions along the reaction paths were analyzed. The two dissociation modes are due to differences in the electron delocalization in the TSs. While the C-2v TS is bonded rather covalently by a three center-four electron (3c-4e) interaction which is lost in a strictly synchronous way (two electrons occupy the same orbital at a time along the reaction coordinate), the bonding orbital in the C-1 TS is merely occupied by a single electron. Surprisingly, this highly polarized TS has a lower barrier. Computations at the CCSD(T)/cc-pVQZ level of theory show that the zero-point corrected enthalpy (Delta H(0)double dagger) of the C-1 TS is 16 kcal mol(-1) above the C-4v symmetric ground state; the barrier along the C-2v path is 40 kcal mol(-1). The overall exothermicity for the dissociation into SH2 and H-2 was estimated to be Delta H-0 = -76 kcal mol(-1). The fundamental IR absorptions of SH4 (obtained by scaling the computed harmonic vibrational frequencies taken from the CCSD(T)/cc-pVQZ level of theory) are 1432 and 2037 cm(-1).

Harvard-Zitierstil: Wittkopp, A., Prall, M., Schreiner, P. and Schaefer, H. (2000) Is SH4, the simplest 10-S-4 sulfurane, observable?, Physical Chemistry Chemical Physics, 2(10), pp. 2239-2244. https://doi.org/10.1039/b000597p

APA-Zitierstil: Wittkopp, A., Prall, M., Schreiner, P., & Schaefer, H. (2000). Is SH4, the simplest 10-S-4 sulfurane, observable?. Physical Chemistry Chemical Physics. 2(10), 2239-2244. https://doi.org/10.1039/b000597p