Theoretical N2-broadened halfwidths of (16)O3
1University of Lowell, Center for Atmospheric Research, 450 Aiken Street, Lowell, Massachusetts 01854, USA.
Applied Optics
|June 1, 1985
Summary
This study calculates ozone line shifts and halfwidths due to nitrogen using quantum Fourier transform theory with improved dynamics (QFT-ID). Results show accurate halfwidths, aiding future predictions for atmospheric spectroscopy.
Area of Science:
- Atmospheric Chemistry
- Quantum Mechanics
- Spectroscopy
Background:
- Accurate spectroscopic parameters are crucial for understanding atmospheric composition and radiative transfer.
- Nitrogen is a major component of Earth's atmosphere and significantly influences the spectral lines of other gases like ozone.
- Previous calculations may lack the precision needed for detailed atmospheric modeling.
Purpose of the Study:
- To compute pressure-induced line shifts and halfwidths for ozone perturbed by nitrogen.
- To analyze the dependence of these parameters on rotational quantum numbers (J, Ka) and transition types.
- To validate the computational method against experimental data where available.
Main Methods:
- Utilizing the quantum Fourier transform theory with improved dynamics (QFT-ID).
- Calculating all unique rotational transitions (J=1 to 35) from the AFGL main gas atlas.
- Examining halfwidth variations across a comprehensive range of quantum states.
Main Results:
- Ozone halfwidths perturbed by nitrogen were accurately calculated, showing 5-10% agreement with experimental data.
- Line shifts were computed for a wide range of transitions, though experimental validation is pending.
- The study provides the first comprehensive analysis of halfwidth dependence on J, Ka, and transition type.
Conclusions:
- The QFT-ID method provides accurate predictions for ozone halfwidths.
- Calculated line shifts can serve as valuable predictions for future experimental studies.
- This work enhances the spectroscopic database for ozone, crucial for atmospheric remote sensing and climate modeling.
More Related Videos
08:22Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
09:40Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
Related Concept Videos
01:23IR Spectrum Peak Broadening: Hydrogen Bonding
The vibrational frequency of a bond is directly proportional to its bond strength. As a result, stronger bonds vibrate at higher frequencies, while weaker bonds vibrate at lower frequencies. The stretching vibration of the strong O–H bond in alcohols and phenols (very dilute solution or gas phase) appears as a sharp peak at 3600–3650 cm−1.
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...
03:51Molecular Orbital Theory II
Molecular Orbital Energy Diagrams
01:24IR Frequency Region: X–H Stretching
In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of 2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in the 3500–3100 cm−1 range. Even though both O−H and N−H bonds vibrate at a similar...
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single stretching vibration...
01:13¹H NMR: Complex Splitting
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
01:22IR Frequency Region: Alkyne and Nitrile Stretching
Both alkyne (C≡C) and nitrile (C≡N) functional groups contain triple bonds and show stretching absorptions around the wavenumber range of 2100 to 2300 cm−1 in the diagnostic region of the IR spectra.
Comparing the stretching vibrational frequency of C≡C triple bonds with that of double and single bonds, it is evident that C≡C triple bonds exhibit a higher stretching frequency than C=C double and C–C single bonds. Similarly, the C≡N triple bond exhibits higher stretching absorption than the C=N...
Comparing the stretching vibrational frequency of C≡C triple bonds with that of double and single bonds, it is evident that C≡C triple bonds exhibit a higher stretching frequency than C=C double and C–C single bonds. Similarly, the C≡N triple bond exhibits higher stretching absorption than the C=N...