skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structure of the sulfuric acid-ammonia system and the effect of water molecules in the gas phase

Abstract

The proton-transfer reaction of sulfuric acid (H{sub 2}SO{sub 4}) and ammonia (NH{sub 3}) and the effect of the first two water (H{sub 2}O) molecules were studied by density functional theory and ab initio molecular orbital theory. The equilibrium structures, binding energies, and harmonic frequencies were calculated for each of the three clusters H{sub 2}SO{sub 4}-NH{sub 3}-(H{sub 2}O){sub n} (n = 0, 1, 2) using the hybrid density functional (B3LYP) and the second-order Moeller-Plesset perturbation approximation (MP2) methods with the 6-311++G(d,p) basis set. Without water (n = 0), the H{sub 2}SO{sub 4}-NH{sub 3} system was determined to be only hydrogen bonded, with H{sub 2}SO{sub 4} acting as the hydrogen-bond donor and NH{sub 3} as the acceptor. However, in the presence of one or two water molecules (n = 1 or 2), the H{sub 2}SO{sub 4}-NH{sub 3} unit exists only as the NH{sub 4}{sup +}{center{underscore}dot}H{sub 2}SO{sub 4}{sup {minus}} ion pair that results from a complete proton transfer from H{sub 2}SO{sub 4} to NH{sub 3}. The analysis of selected equilibrium bond lengths, binding energies, and harmonic frequencies of the clusters provided strong support for the complete proton transfer in the presence of one or two water molecules. Atmospheric implications of the study aremore » discussed.« less

Authors:
; ;
Publication Date:
Research Org.:
California State Univ., Fullerton, CA (US)
OSTI Identifier:
20000064
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory
Additional Journal Information:
Journal Volume: 103; Journal Issue: 34; Other Information: PBD: 26 Aug 1999; Journal ID: ISSN 1089-5639
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ATMOSPHERIC CHEMISTRY; SULFURIC ACID; AMMONIA; WATER VAPOR; MOLECULAR ORBITAL METHOD; THEORETICAL DATA; EQUILIBRIUM; AEROSOLS; PARTICULATES

Citation Formats

Larson, L.J., Largent, A., and Tao, F.M. Structure of the sulfuric acid-ammonia system and the effect of water molecules in the gas phase. United States: N. p., 1999. Web. doi:10.1021/jp991529p.
Larson, L.J., Largent, A., & Tao, F.M. Structure of the sulfuric acid-ammonia system and the effect of water molecules in the gas phase. United States. doi:10.1021/jp991529p.
Larson, L.J., Largent, A., and Tao, F.M. Thu . "Structure of the sulfuric acid-ammonia system and the effect of water molecules in the gas phase". United States. doi:10.1021/jp991529p.
@article{osti_20000064,
title = {Structure of the sulfuric acid-ammonia system and the effect of water molecules in the gas phase},
author = {Larson, L.J. and Largent, A. and Tao, F.M.},
abstractNote = {The proton-transfer reaction of sulfuric acid (H{sub 2}SO{sub 4}) and ammonia (NH{sub 3}) and the effect of the first two water (H{sub 2}O) molecules were studied by density functional theory and ab initio molecular orbital theory. The equilibrium structures, binding energies, and harmonic frequencies were calculated for each of the three clusters H{sub 2}SO{sub 4}-NH{sub 3}-(H{sub 2}O){sub n} (n = 0, 1, 2) using the hybrid density functional (B3LYP) and the second-order Moeller-Plesset perturbation approximation (MP2) methods with the 6-311++G(d,p) basis set. Without water (n = 0), the H{sub 2}SO{sub 4}-NH{sub 3} system was determined to be only hydrogen bonded, with H{sub 2}SO{sub 4} acting as the hydrogen-bond donor and NH{sub 3} as the acceptor. However, in the presence of one or two water molecules (n = 1 or 2), the H{sub 2}SO{sub 4}-NH{sub 3} unit exists only as the NH{sub 4}{sup +}{center{underscore}dot}H{sub 2}SO{sub 4}{sup {minus}} ion pair that results from a complete proton transfer from H{sub 2}SO{sub 4} to NH{sub 3}. The analysis of selected equilibrium bond lengths, binding energies, and harmonic frequencies of the clusters provided strong support for the complete proton transfer in the presence of one or two water molecules. Atmospheric implications of the study are discussed.},
doi = {10.1021/jp991529p},
journal = {Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory},
issn = {1089-5639},
number = 34,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}