Near-UV absorption cross sections and trans/cis equilibrium of nitrous acid

Journal Article · Thu Feb 07 00:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100156a012· OSTI ID:5231090

Bongartz, A; Kames, J; Welter, F; Schurath, U ^[1]

---

1. Univ. Bonn (West Germany)

The A {sup 1}A{double prime} {l arrow} X {sup 1}A{prime} absorption spectrum of gaseous nitrous acid has been measured in the 300-400-nm range. Absolute cross sections were determined by a combination of gas-phase and wet chemical analysis. The cross sections of prominent bands are 25% larger than the recommended values of Stockwell and Calvert. The influence of spectral resolution on absolute and differential absorption cross sections was also investigated. The integrated band area of the n{pi}* transition yields an oscillator strength f = (8.90 {plus minus} 0.36) {times} 10{sup {minus}4}, less than the reported liquid phase value of 2 {times} 10{sup {minus}3}. The equilibrium constant K = p{sub trans}/p{sub cis}, based on the assumption that the oscillator strength of the n{pi}* transition is the same for both rotamers, was found to be 3.25 {plus minus} 0.30 at 277 K. This yields an energy difference {Delta}E between trans- and cis-HONO of -2,700 J mol{sup {minus}1} in the electronic ground state, and -6,000 J mol{sup {minus}1} in the excited state.

• OSTI ID: 5231090
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:3; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
NITROUS ACID
ABSORPTION SPECTRA
ATMOSPHERIC CHEMISTRY
DIFFERENTIAL CROSS SECTIONS
EXPERIMENTAL DATA
GAS ANALYSIS
SPECTRAL RESPONSE
CHEMISTRY
CROSS SECTIONS
DATA
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
NUMERICAL DATA
SPECTRA
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
400102 - Chemical & Spectral Procedures