Return to search

Theoretical Studies of Atmospheric Water Complexes

Intermolecular complexes between H₂O and atmospheric species HO, HO₂, H₂O₂, O₃, NO and NO₂ have been studied by ab initio molecular orbital methods. The studies have been performed to the MP2 theory level by using 4-31G, 6-31G, D95, 6-31G**, D95**, 6-311G**, 6-311+G**, 6-311++G**, 6-311+G(2d,lp) and 6-311+G(2d,2p) basis sets. The geometries were fully optimized. The vibrational frequencies were calculated. The Basis Set Superposition Error (BSSE) were estimated. Finally, the binding energies of the complexes were predicted with other thermochemical properties. The binding energies of H₂O•HO, H₂O•HO₂, H₂O•H₂O₂, H₂O•O₃, H₂O•NO and H₂O•NO₂ are estimated to be 5.7±0.6, 8.9±1.0, 7.3±1.3, 1.8±0.2, 1.17 (no BSSE correction) and 2.98 (no BSSE correction) Kcal/Mol, respectively. The Kcq for dimerization to yield H₂O•HO, H₂O•HF, H₂O•HO₂, H₂O•H₂O and H₂O•H₂O₂ are estimated to be 0.11, 2.8, 3.3, 0.067 and 0.11 atm¯¹, respectively. The H₂O•HO, H₂O•HF, H₂O•HO₂, H₂O•H₂O and H₂O•H₂O₂ are quite strongly bonded complexes, while H₂O•O₃, H₂O•NO and H₂O•NO₂ are only weakly bonded complexes. The Kcq changes with temperature are discussed, and their importance in atmospheric chemistry are addressed.

Identiferoai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-2162
Date01 January 1992
CreatorsPan, Xiong
PublisherPDXScholar
Source SetsPortland State University
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceDissertations and Theses

Page generated in 0.0019 seconds