ISSN:
1432-2234
Keywords:
Hydrogen nitryl (HNO2)
;
Nitro compound
;
Hydrogen migration
;
Isomerization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary Electronic structure of hydrogen nitryl HNO2, a yet not identified entity, and the path of its possible isomerization totrans-HONO have been investigated byab initio SCF and MRD-CI computations using the 6-31G** basis set. HNO2 isC 2v -symmetric and its ground state (1 A 1) is less stable thantrans-HONO by 66 kJ/mol (with the SCF vibrational zero-point energy correction). The lowest two excited singlet states (1 A 2 and1 B 1) are nearly degenerate, their vertical excitation energies being predicted to be 4.8 eV. The isomerization path is traced by the CASSCF procedure and the activation barrier height is evaluated by the CI treatment. HNO2 in its ground state isomerizes totrans-HONO by maintaining the planar (C s-symmetric) structure. The activation energy is calculated to be 171 kJ/mol, which is clearly lower than the calculated H-N bond energy (253 kJ/mol). The transition state seems to be more adequately described as an interacting system of proton and the nitrite anion rather than as a pair of two fragment radicals.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01127806
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