Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations
Chloromethane (CH<sub>3</sub>Cl) is a key chlorinated organic compound not only in atmospheric chemistry, but also in the field of molecular astrophysics and a possible biosignature in exoplanetary atmospheres. While the spectroscopic characterization of the main isotopic species has bee...
Saved in:
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-04-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/30/7/1604 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849730395149434880 |
|---|---|
| author | Mattia Melosso Paolo Stoppa Daniela Alvarado-Jiménez Filippo Tamassia Carlotta Sapienza Luca Bizzocchi Luca Dore Cristina Puzzarini Andrea Pietropolli Charmet Nicola Tasinato |
| author_facet | Mattia Melosso Paolo Stoppa Daniela Alvarado-Jiménez Filippo Tamassia Carlotta Sapienza Luca Bizzocchi Luca Dore Cristina Puzzarini Andrea Pietropolli Charmet Nicola Tasinato |
| author_sort | Mattia Melosso |
| collection | DOAJ |
| description | Chloromethane (CH<sub>3</sub>Cl) is a key chlorinated organic compound not only in atmospheric chemistry, but also in the field of molecular astrophysics and a possible biosignature in exoplanetary atmospheres. While the spectroscopic characterization of the main isotopic species has been addressed in great detail, that of its isotopologues remains incomplete. This work aims at filling this gap by focusing on the bideuterated species, CHD<sub>2</sub>Cl, and exploiting both rotational and vibrational spectroscopy in combination with state-of-the-art quantum-chemical (QC) calculations. First, the rotational spectrum of CHD<sub>2</sub>Cl has been measured in the millimeter-wave domain, allowing the accurate determination of several spectroscopic constants for four isotopologues, namely <sup>12</sup>CHD<sub>2</sub><sup>35</sup>Cl, <sup>12</sup>CHD<sub>2</sub><sup>37</sup>Cl, <sup>13</sup>CHD<sub>2</sub><sup>35</sup>Cl, and <sup>13</sup>CHD<sub>2</sub><sup>37</sup>Cl. The newly determined rotational constants have been used to refine the semi-experimental equilibrium structure of chloromethane. Secondly, the vibrational analysis, supported by high-level QC predictions of vibrational energies, has been conducted in the 500–6200 cm<sup>−1</sup> infrared (IR) region, enabling the identification of more than 30 bands including fundamental, overtone, and combination transitions. Finally, chloromethane’s radiative efficiency has been simulated using the QC IR absorption cross-sections, and the effects of isotopologue distribution on the predicted radiative properties have been investigated. All these findings greatly improve the comprehension of the spectroscopic properties of bideuterated chloromethane isotopologues, and of chloromethane in general, and facilitate future terrestrial and extraterrestrial studies. |
| format | Article |
| id | doaj-art-a5d951e70d6841d8a4618f863f2c126b |
| institution | DOAJ |
| issn | 1420-3049 |
| language | English |
| publishDate | 2025-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj-art-a5d951e70d6841d8a4618f863f2c126b2025-08-20T03:08:53ZengMDPI AGMolecules1420-30492025-04-01307160410.3390/molecules30071604Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical CalculationsMattia Melosso0Paolo Stoppa1Daniela Alvarado-Jiménez2Filippo Tamassia3Carlotta Sapienza4Luca Bizzocchi5Luca Dore6Cristina Puzzarini7Andrea Pietropolli Charmet8Nicola Tasinato9Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, ItalyDipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, ItalyScuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, 56126 Pisa, ItalyDipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, Via Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, ItalyDipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, ItalyScuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, 56126 Pisa, ItalyChloromethane (CH<sub>3</sub>Cl) is a key chlorinated organic compound not only in atmospheric chemistry, but also in the field of molecular astrophysics and a possible biosignature in exoplanetary atmospheres. While the spectroscopic characterization of the main isotopic species has been addressed in great detail, that of its isotopologues remains incomplete. This work aims at filling this gap by focusing on the bideuterated species, CHD<sub>2</sub>Cl, and exploiting both rotational and vibrational spectroscopy in combination with state-of-the-art quantum-chemical (QC) calculations. First, the rotational spectrum of CHD<sub>2</sub>Cl has been measured in the millimeter-wave domain, allowing the accurate determination of several spectroscopic constants for four isotopologues, namely <sup>12</sup>CHD<sub>2</sub><sup>35</sup>Cl, <sup>12</sup>CHD<sub>2</sub><sup>37</sup>Cl, <sup>13</sup>CHD<sub>2</sub><sup>35</sup>Cl, and <sup>13</sup>CHD<sub>2</sub><sup>37</sup>Cl. The newly determined rotational constants have been used to refine the semi-experimental equilibrium structure of chloromethane. Secondly, the vibrational analysis, supported by high-level QC predictions of vibrational energies, has been conducted in the 500–6200 cm<sup>−1</sup> infrared (IR) region, enabling the identification of more than 30 bands including fundamental, overtone, and combination transitions. Finally, chloromethane’s radiative efficiency has been simulated using the QC IR absorption cross-sections, and the effects of isotopologue distribution on the predicted radiative properties have been investigated. All these findings greatly improve the comprehension of the spectroscopic properties of bideuterated chloromethane isotopologues, and of chloromethane in general, and facilitate future terrestrial and extraterrestrial studies.https://www.mdpi.com/1420-3049/30/7/1604chlorocarbonsrotational spectroscopyvibrational spectroscopyequilibrium structurequantum chemistryclimate metrics |
| spellingShingle | Mattia Melosso Paolo Stoppa Daniela Alvarado-Jiménez Filippo Tamassia Carlotta Sapienza Luca Bizzocchi Luca Dore Cristina Puzzarini Andrea Pietropolli Charmet Nicola Tasinato Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations Molecules chlorocarbons rotational spectroscopy vibrational spectroscopy equilibrium structure quantum chemistry climate metrics |
| title | Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations |
| title_full | Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations |
| title_fullStr | Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations |
| title_full_unstemmed | Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations |
| title_short | Completing the Spectral Mosaic of Chloromethane by Adding the CHD<sub>2</sub>Cl Missing Piece Through the Interplay of Rotational/Vibrational Spectroscopy and Quantum Chemical Calculations |
| title_sort | completing the spectral mosaic of chloromethane by adding the chd sub 2 sub cl missing piece through the interplay of rotational vibrational spectroscopy and quantum chemical calculations |
| topic | chlorocarbons rotational spectroscopy vibrational spectroscopy equilibrium structure quantum chemistry climate metrics |
| url | https://www.mdpi.com/1420-3049/30/7/1604 |
| work_keys_str_mv | AT mattiamelosso completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT paolostoppa completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT danielaalvaradojimenez completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT filippotamassia completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT carlottasapienza completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT lucabizzocchi completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT lucadore completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT cristinapuzzarini completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT andreapietropollicharmet completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations AT nicolatasinato completingthespectralmosaicofchloromethanebyaddingthechdsub2subclmissingpiecethroughtheinterplayofrotationalvibrationalspectroscopyandquantumchemicalcalculations |