Abstract
Oxywater(HOO) is an intermediate in the oxidation of hydrogen peroxide (HOOH), and along with its relatives H
SS and H
SeSe, plays an important role in atmospheric and biochemical processes. In this research, we study the isomerisation of H
XY species to HXYH (X, Y = O, S, Se) using ab initio methods. Geometries and harmonic frequencies were obtained using both a scalar relativistic X2C-1e-CCSD(T) approach and non-relativistic CCSD(T) using an effective core potential on Se. A focal point approach was used to extrapolate electronic energies at CCSD(T)/aug-cc-pVTZ geometries to a CCSDT(Q)/CBS level of theory. The isomerisation reactions of H
XX to HXXH have barriers of 6.6, 20.6, and 14.1 kcal mol
and exothermicities of 45.8, 27.2, and 28.3 kcal mol
for X=O, S, and Se, respectively. The isomerisation reactions of H
OS and H
SO to HOSH have barriers of 15.4 and 44.2 kcal mol
and exothermicities of 36.2 and 17.7 kcal mol
. The isomerisation reactions of H
OSe and H
SeO to HOSeH have barriers of 10.1 and 36.2 kcal mol
and exothermicities of 33.5 and 31.7 kcal mol
. The isomerisation reactions of H
SSe and H
SeS to HSSeH have barriers of 16.2 and 18.1 kcal mol
and exothermicities of 23.3 and 32.1 kcal mol
.
GRAPHICAL ABSTRACT
![](/cms/asset/7c470c47-2565-4f76-b67a-b331aeeec3c0/tmph_a_1976429_uf0001_oc.jpg)
Disclosure statement
No potential conflict of interest was reported by the author(s).