Thermodynamics of OHgX, XHgOH, XHgOCl, XHgOBr, and HOHgY Gaseous Oxidized Mercury Molecules from Isodesmic, Isogyric, and Atomization Work Reactions (X = Halogen, y = OH, OCl, OBr)
Document Type
Article
Publication Date
5-23-2019
Abstract
Isogyric, isodesmic, and atomization reactions were used to determine the standard enthalpies of formation (ΔH°f) for a series of OHgX, XHgOH, XHgOCl, XHgOBr, and HOHgY molecules (X = halogen, Y = OH, OCl, OBr) from single-point CCSD(T)/AVnZ//M06-2X/AVTZ (n = D, T, Q) energies extrapolated to the complete basis set limit using a three-point mixed Gaussian exponential scheme. Standard enthalpies of formation from isogyric and isodesmic reactions are in good agreement with experimental data and values from higher level calculations but at significantly reduced computation time. The established template work reaction scheme and methodology can potentially be extended for Hg species outside the scope of this work. The standard error for the ΔH°f for the studied molecules averaged over several isodesmic/isogyric reactions is 1.67 kcal/mol or less. The X-Hg-Y bond dissociation energies (BDEs) were determined from the ΔH°f and used as a metric of the molecular stability. The BDE decreases from F to I for the X-HgOH and OHg-X series. The trend is reversed for X-HgOCl and X-HgOBr where the BDE increases from F to Br but decreases with I. All studied molecules have significant BDEs in the range of 50-90 kcal/mol. Assuming that the concentrations of halogens OH, OCl, or OBr are reasonably high near the vicinity of a mercury emission source, the studied molecules can potentially exist long enough to affect the mercury oxidation-reduction rate and impact the global mercury budget. ©
Identifier
85066148106 (Scopus)
Publication Title
Journal of Physical Chemistry A
External Full Text Location
https://doi.org/10.1021/acs.jpca.9b01358
e-ISSN
15205215
ISSN
10895639
PubMed ID
30998008
First Page
4452
Last Page
4464
Issue
20
Volume
123
Recommended Citation
Guzman, Francisco J. and Bozzelli, Joseph, "Thermodynamics of OHgX, XHgOH, XHgOCl, XHgOBr, and HOHgY Gaseous Oxidized Mercury Molecules from Isodesmic, Isogyric, and Atomization Work Reactions (X = Halogen, y = OH, OCl, OBr)" (2019). Faculty Publications. 7587.
https://digitalcommons.njit.edu/fac_pubs/7587
