Halogenated volatile organic compounds (HVOCs) are photochemically reactive compounds, primarily emitted from the ocean. One potential anthropogenic source of HVOCs is treated ballast water, where they are formed as disinfection byproducts. After being released from the open ocean or treated water in harbors, HVOCs can impact the atmosphere’s oxidation capacity and have a significant potential for ozone destruction.
We provide high-resolution spectra of reactive HVOCs, e.g., CH2Br2, CHBr3, and CH3I. We introduced high-precision spectroscopic parameters of the rovibrational transitions of these molecules from frequency comb-based measurements. We extensively use spectral simulation tools to assign the measured spectra. The line lists are used to create spectroscopic models for the HITRAN databases. For example, the line list and intensities of the rovibrational transitions of the ν4 band of CH3I were incorporated in the HITRAN database.
(a) Measured high-resolution spectrum of CH3I in the mid-infrared region from 2800 cm-1 to 3190 cm-1. In this range the spectrum of CH3I compromise three rovibrational structures: the asymmetric CH vibration, ν4, around 3100 cm-1, the symmetric CH vibration, ν1, around 2975 cm-1, and a group of parallel vibrations around 2850 cm-1. (b – c) Zoomed in windows at the different spectral regions.
Selected Publications:
[1] Hjältén A, Foltynowicz A, Sadiek I Line positions and intensities of the ν1 band of 12CH3I using mid-infrared optical frequency comb Fourier transform spectroscopy. J. Quant. Spectroc. Radiat. Transfer. 2023;306:108646/1-10.
[2] Sadiek I, Hjältén A, Roberts FC, Lehman JH, Foltynowicz A Optical frequency comb-based measurements and the revisited assignment of high-resolution spectra of CH2Br2 in the 2960 to 3120 cm−1 region. Phys. Chem. Chem. Phys. 2023;25, 8743-8754.
[3] Sadiek I, Hjältén A, Senna Vieira F, Lu C, Stuhr M, Foltynowicz A. Line positions and intensities of the ν4 band of methyl iodide using mid-infrared optical frequency comb Fourier transform spectroscopy. J. Quant. Spectroc. Radiat. Transfer. 2020;255:107263/1-8.