Vol. 38, issue 11, article # 3
Copy the reference to clipboard
Abstract:
Chloroform is one of dangerous pollutants in the atmosphere. To control it in the atmosphere by absorption spectroscopy, it is necessary to know the position of its spectral lines. In this work, the absorption spectra of CH37Cl3 isotopologue of gaseous chloroform are measured using a high-resolution nonstationary spectrometer in the frequency range 118–175 GHz, where spectroscopic data for this compound are absent. The identification of the chloroform lines presented in the literature and assigned to the vibrational state n2 for CH35Cl3 is refined and their belonging to CH37Cl3 isotopologue is shown. The experimental results are compared with our theoretical estimates of absorption lines centers of the rotational spectrum of this molecule in the same spectral range. Absorption lines of CH37Cl3 isotopologue in the ground state were detected and identified in the spectral subranges near 131.4, 137.6, 150.1, and 156.4 GHz. Based on the experimental spectra, we have estimated the molecular constants B = 3129.56 MHz, DJ = 1.34 kHz, and DJK = -2.25 kHz with RMSE = 7.84 ´ 10-2 MHz, which determine transition frequencies in absorption spectra parts near 150.1 GHz and 156.4 GHz more accurately than molecular constants given in the literature (B = 3129.61 MHz, DJ = 1.37 kHz, and DJK = -2.28 kHz with RMSE = 11.55 × 10-2 MHz). The results can be used for controlling the content of chloroform in the atmosphere.
Keywords:
chlorine-containing atmospheric gases, chloroform, rotational spectrum, terahertz high-resolution nonstationary spectroscopy
Figures:
References:
1. Kistenev Yu.V., Cuisset A., Romanovskii O.A., Zherdeva A.V. Issledovanie malykh gazovykh sostavlyayushchikh na granitse «vodnaya poverkhnost' – atmosfera» s ispol'zovaniem sredstv distantsionnogo i lokal'nogo lazernogo IK-gazoanaliza. Obzor // Optika atmosf. i okeana. 2022. V. 35, N 10. P. 799–810. DOI: 10.15372/AOO20221002; Kistenev Yu.V., Cuisset A., Romanovskii O.A., Zherdeva A.V. A study of trace atmospheric gases at the water – atmosphere interface using remote and local IR laser gas analysis: A review // Atmos. Ocean. Opt. 2022. V. 35, suppl. 1. P. S17–S29. DOI: 10.1134/S1024856023010074.
2. Scientific Assessment of Stratospheric Ozone: 1989: World Meteorological Organization Global Ozone Research and Monitoring Project – Report N 20. Geneva: WMO, 1989. 532 p.
3. Scientific Assessment of Ozone Depletion: 1994: World Meteorological Organization Global Ozone Research and Monitoring Project – Report N 37. Geneva: WMO, 1994. 29 p.
4. Study Finds Chloroform Emissions, on the Rise in East Asia, Could Delay Ozone Recovery by up to Eight Years. URL: https://phys.org/news/2018-12-chloroform-emissions-east-asia-ozone.html (last access: 16.01.2025).
5. Locating and Estimating Air Emissions from Sources of Chloroform. U.S. Environmental Protection Agency. Office of Air Quality Planning and Standards Research Triangle Park, North Carolina 27711, 1984. 101 p.
6. Carpenter J.H., Seo P.J., Whiffen D.H. The rotational spectrum of chloroform in its ground and excited vibrational states // J. Mol. Spectrosc. 1995. V. 170. P. 215–227. DOI: 10.1006/jmsp.1995.1066.
7. Cazzoli G., Cotti G., Dore L. Millimeter and submillimeter-wave spectrum of CHCl3. Determination of the h3, splitting constant // Chem. Phys. Lett. 1993. V. 203, N 2–3. P. 227–231. DOI: 10.1016/0009-2614(93)85392-2.
8. Submillimeter, Millimeter, and Microwave Spectral Line Catalog. JPL Molecular Spectroscopy. URL: http://spec.jpl.nasa.gov/ftp/pub/catalog/catform.html (last access: 17.01.2025).
9. Endres C.P., Schlemmer S., Schilke P., Stutzki J., Müller H.S.P. The Cologne. Database for Molecular Spectroscopy, CDMS // J. Mol. Spectrosc. 2016. V. 327. P. 95–104. DOI: 10.1016/j.jms.2016.03.005.
10. Gordon I.E., Rothman L.S., Hargreaves R.J., Hashemi R., Karlovets E.V., Skinner F.M., Conway E.K., Hill C., Kochanov R.V., Tan Y., Wcisło P., Finenko A.A., Nelson K., Bernath P.F., Birk M., Boudon V., Campargue A., Chance K.V., Coustenis A., Drouin B.J., Flaud J.-M., Gamache R.R., Hodges J.T., Jacquemart D., Mlawer E.J., Nikitin A.V., Perevalov V.I., Rotger M., Tennyson J., Toon G.C., Tran H., Tyuterev V.G., Adkins E.M., Baker A., Barbe A., Canè E., Császár A.G., Dudaryonok A., Egorov O., Fleisher A.J., Fleurbaey H., Foltynowicz A., Furtenbacher T., Harrison J.J., Hartmann J.-M., Horneman V.-M., Huang X., Karman T., Karns J., Kassi S., Kleiner I., Kofman V., Kwabia-Tchana F., Lavrentieva N.N., Lee T.J., Long D.A., Lukashevskaya A.A., Lyulin O.M., Makhnev V.Yu., Matt W., Massie S.T., Melosso M., Mikhailenko S.N., Mondelain D., Müller H.S.P., Naumenko O.V., Perrin A., Polyansky O.L., Raddaoui E., Raston P.L., Reed Z.D., Rey M., Richard C., Tóbiás R., Sadiek I., Schwenke D.W., Starikova E., Sung K., Tamassia F., Tashkun S.A., Vander Auwera J., Vasilenko I.A., Vigasin A.A., Villanueva G.L., Vispoel B., Wagner G., Yachmenev A., Yurchenko S.N. The HITRAN2020 molecular spectroscopic database // J. Quant. Spectrosc. Radiat. Transfer. 2022. V. 277. P. 107949. DOI: 10.1016/j.jqsrt.2021.107949.
11. Vaks V.L., Anfertev V.A., Balakirev V.Yu., Basov S.A., Domracheva E.G., Illyuk A.V., Kupriyanov P.V., Pripolzin S.I., Chernyaeva M.B. High resolution terahertz spectroscopy for analytical applications // Phys. Usp. 2020. V. 63. P. 708–720. DOI: 10.3367/UFNe.2019.07.038613.
12. Gordy W., Cook R.L. Microwave Molecular Spectra. New York: J. Wiley & Sons, 1984. 929 p.
13. Townes C.H., Schawlow A.L. Microwave Spectroscopy. New York: McGraw-Hill, 1955. 720 p.
14. Colmont J.-M., Priem D., Drean P., Demaison J., Boggs J.E. Rotational spectra of the isotopic species of chloroform: Experimental and ab initio structures // J. Mol. Spectrosc. 1998. V. 191. P. 158–175. DOI: 10.1006/jmsp.1998.7623.
15. Mitchell M. An Introduction to Genetic Algorithms. London: MIT Press, 1998. 158 p.
16. Levenberg K. A method for the solution of certain non-linear problems in least squares // Quart. Appl. Math. 1944. V. 2, N 2. P. 164–168.
