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Structure, binding energy, and equilibrium constant of the nitric acid‐Water complex
Author(s) -
Tao FuMing,
Higgins Kelly,
Klemperer William,
Nelson David D.
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl00947
Subject(s) - nitric acid , hydrogen bond , equilibrium constant , binding energy , chemistry , hydrogen , oxygen , hydrogen atom , molecule , ab initio , ab initio quantum chemistry methods , bond length , crystallography , inorganic chemistry , atomic physics , group (periodic table) , organic chemistry , physics
The nitric acid‐water complex is studied by high level ab initio calculations. The equilibrium structure of the complex has an asymmetric doubly hydrogen‐bonded ring. A strong hydrogen bond is donated by the hydroxyl group of nitric acid to the oxygen atom of water, and a much weaker hydrogen bond is donated by an OH bond of water to a second oxygen of nitric acid. The HNO 3 unit in the complex is considerably distorted with the OH stretching frequency red‐shifted by over 300 cm −1 from the isolated molecule and the infrared intensity enhanced by an order of magnitude. The binding energy of the complex is calculated as D e = −9.5 kcal/mol. The equilibrium fraction of nitric acid complexed with water is predicted to be near 1% at the Earth's surface and falls with the increase of altitude.