title: Computational studies on metathetical and redox processes of HOCl in gas phase. III. Its self-reaction and interactions with HNOx (x = 1-3).
abstract: The gas-phase redox reactions of HOCl with its self and HNO(x) (x = 1-3) have been studied theoretically by ab initio quantum chemical and statistical mechanical theories. The structures of reactants, intermediate complexes, products, and transition states were optimized at the MPW1PW91/6-311+G(3df,2p) level of theory. The potential energy surface of each reaction was refined at the CCSD(T)/6-311+G(3df,2p) level of theory. The most favorable products are predicted to be ClClO + H(2)O and ClOCl + H(2)O for the HOCl self-reaction (A), H(2)O + Cl + NO for the HOCl + HNO reaction (B), H(2)O + ClNO(2) for the HOCl + HONO-t reaction (C), H(2)O + cis-ClONO for the HOCl + HONO-c reaction (D). For the HOCl + HONO(2) reaction (E), only one dehydration reaction channel was considered to produce H(2)O + ClONO(2). The rate constants of all above five reactions have been predicted at 300-3000 K by the VTST/RRKM theory. The calculation shows that the theoretical rate constants are within the upper limits of experimental results. In addition, we calculated the equilibrium constant for the Cl(2)O + H(2)O --> HOCl + HOCl reaction, which is also in reasonable agreement with experimental data within the error of the available experimental enthalpy change.
authors.affiliation: Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Z F
authors.initials: ZF
authors.lastname: Xu
authors.forename: M C
authors.initials: MC
authors.lastname: Lin
mesh_terms: D003198:Computer Simulation; D005740:Gases / Q000737:chemistry; D006997:Hypochlorous Acid / Q000737:chemistry*; D017942:Nitric Acid / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D009608:Nitrous Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D011789:Quantum Theory
chemical_list: D005740:Gases; D009589:Nitrogen Oxides; D017942:Nitric Acid; D006997:Hypochlorous Acid; C039900:nitroxyl; D009608:Nitrous Acid