Pub Date : 2025-03-01DOI: 10.1016/j.jms.2025.111998
Tanvi Sattiraju, Jonathan Tennyson
An analysis of the measured rovibrational transitions is carried out for the CS isotopologue of carbon disulfide. Data from 21 sources is extracted and validated using a consistent set of standard linear molecule quantum numbers. A corrected list of 8714 CS transitions forms the input to a Measured Active Rotational–Vibrational Energy Levels (MARVEL) procedure, generating 4279 empirical rovibrational energy levels across 138 bands of CS. Results are compared to the recent NASA Ames line list. While the agreement is generally good, issues are identified with the energy levels of some states, notably those with high values of the bending quantum number.
{"title":"Empirical rovibrational energy levels for carbon disulfide","authors":"Tanvi Sattiraju, Jonathan Tennyson","doi":"10.1016/j.jms.2025.111998","DOIUrl":"10.1016/j.jms.2025.111998","url":null,"abstract":"<div><div>An analysis of the measured rovibrational transitions is carried out for the <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>C<span><math><msup><mrow></mrow><mrow><mn>32</mn></mrow></msup></math></span>S<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> isotopologue of carbon disulfide. Data from 21 sources is extracted and validated using a consistent set of standard linear molecule quantum numbers. A corrected list of 8714 CS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> transitions forms the input to a Measured Active Rotational–Vibrational Energy Levels (MARVEL) procedure, generating 4279 empirical rovibrational energy levels across 138 bands of <span><math><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup></math></span>C<span><math><msup><mrow></mrow><mrow><mn>32</mn></mrow></msup></math></span>S<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. Results are compared to the recent NASA Ames line list. While the agreement is generally good, issues are identified with the energy levels of some states, notably those with high values of the <span><math><msub><mrow><mi>v</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> bending quantum number.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 111998"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2025.111986
Greta Naso , Filippo Baroncelli , Luca Evangelisti , Assimo Maris , Sonia Melandri
The rotational spectrum of trifluoroacetic acid has been recorded at room temperature in the 18–26 GHz frequency range using a chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer. More than 180 new spectral lines have been identified and assigned to transitions within the vibrational ground state. A global fitting has been performed by incorporating spectroscopic data from previous studies, leading to the refinement of the molecular parameters. Two fitting models using Watson’s -reduction and -reduction are proposed, allowing the determination of for the first model and , , and for the second one.
{"title":"Rotational spectrum of trifluoroacetic acid: Extension of the measurements by chirped-pulse spectroscopy","authors":"Greta Naso , Filippo Baroncelli , Luca Evangelisti , Assimo Maris , Sonia Melandri","doi":"10.1016/j.jms.2025.111986","DOIUrl":"10.1016/j.jms.2025.111986","url":null,"abstract":"<div><div>The rotational spectrum of trifluoroacetic acid has been recorded at room temperature in the 18–26 GHz frequency range using a chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer. More than 180 new spectral lines have been identified and assigned to transitions within the vibrational ground state. A global fitting has been performed by incorporating spectroscopic data from previous studies, leading to the refinement of the molecular parameters. Two fitting models using Watson’s <span><math><mi>S</mi></math></span>-reduction and <span><math><mi>A</mi></math></span>-reduction are proposed, allowing the determination of <span><math><msub><mrow><mi>h</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> for the first model and <span><math><msub><mrow><mi>Φ</mi></mrow><mrow><mi>J</mi><mi>K</mi></mrow></msub></math></span>, <span><math><msub><mrow><mi>Φ</mi></mrow><mrow><mi>K</mi><mi>J</mi></mrow></msub></math></span>, and <span><math><msub><mrow><mi>ϕ</mi></mrow><mrow><mi>K</mi></mrow></msub></math></span> for the second one.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111986"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2025.111999
Kristin N. Bales , Dominik Kosican , Jack C. Harms , James J. O’Brien , Leah C. O’Brien
Two transitions of tungsten sulfide (WS) near 13,100 cm−1, the (0,0) band of the [13.10]1 –X3Σ−0+ transition and the (0,0) band of the [15.30]1 –X3Σ−1 transition, have been recorded at high resolution using intracavity laser absorption spectroscopy with a Fourier-transform spectrometer used for detection (ILS-FTS). The WS molecules were produced in the plasma discharge formed by applying 0.70–0.80 A of a discharge current from a pulsed DC plasma generator to a tungsten-lined copper hollow cathode. The reaction took place in the presence of Ar (∼70 %), H2 (∼30 %), and CS2 (∼0.1 %) gases at a total pressure of approximately 2 torr. Lines for all four abundant isotopologues of WS, 182W32S, 183W32S, 184W32S, and 186W32S, were measured and a rotational analysis was performed using PGOPHER. A constrained parameters approach was used to maintain expected mass relationships among isotopologues. This analysis increases the number of observed rotational levels from J ∼ 30 to J ∼ 100 for both excited states, allowing an increase in precision of spectroscopic constants. The new analysis of the [15.30]1 –X3Σ−(1) transition enabled the reduced uncertainty in the previously determined value for the splitting of the 0+ and 1 Ω-components of the X3Σ− ground state. Also presented in this work is an expansion upon our earlier deperturbation analysis involving the [15.30]1 state to include the v′ = 2 vibrational level, which is perturbed by the v′ = 4 vibrational level of the [14.26]0+ state.
利用用于探测的傅立叶变换光谱仪（ILS-FTS），以高分辨率记录了硫化钨（WS）在13100 cm−1附近的两个跃迁，即[13.10]1 - X 3Σ−0+跃迁的（0,0）波段和[15.30]1 - X 3Σ−1跃迁的（0,0）波段。在脉冲直流等离子体发生器中施加0.70-0.80 A的放电电流到钨衬里铜空心阴极形成等离子体放电，产生WS分子。反应发生在Ar（~ 70%）、H2（~ 30%）和CS2（~ 0.1%）气体存在下，总压力约为2torr。测定了182W32S、183W32S、184W32S和186W32S四种富集同位素谱，并用PGOPHER进行了旋转分析。使用约束参数方法来维持同位素间的期望质量关系。该分析将两个激发态的观测旋转能级从J ~ 30增加到J ~ 100，从而提高了光谱常数的精度。对[15.30]1 - X 3Σ−(1)跃迁的新分析使先前确定的X 3Σ−基态0+和1 Ω-components分裂值的不确定性降低。这项工作还提出了对我们先前涉及[15.30]1状态的解摄动分析的扩展，以包括v ' = 2振动能级，它被[14.26]0+状态的v ' = 4振动能级摄动。
{"title":"Rotational analyses of two transitions of WS near 13,100 cm−1, and further deperturbation analysis of the [15.30]1 – X 3Σ−0+ transition","authors":"Kristin N. Bales , Dominik Kosican , Jack C. Harms , James J. O’Brien , Leah C. O’Brien","doi":"10.1016/j.jms.2025.111999","DOIUrl":"10.1016/j.jms.2025.111999","url":null,"abstract":"<div><div>Two transitions of tungsten sulfide (WS) near 13,100 cm<sup>−1</sup>, the (0,0) band of the [13.10]1 <strong>–</strong> <em>X</em> <sup>3</sup>Σ<sup>−</sup><sub>0+</sub> transition and the (0,0) band of the [15.30]1 <strong>–</strong> <em>X</em> <sup>3</sup>Σ<sup>−</sup><sub>1</sub> transition, have been recorded at high resolution using intracavity laser absorption spectroscopy with a Fourier-transform spectrometer used for detection (ILS-FTS). The WS molecules were produced in the plasma discharge formed by applying 0.70–0.80 A of a discharge current from a pulsed DC plasma generator to a tungsten-lined copper hollow cathode. The reaction took place in the presence of Ar (∼70 %), H<sub>2</sub> (∼30 %), and CS<sub>2</sub> (∼0.1 %) gases at a total pressure of approximately 2 torr. Lines for all four abundant isotopologues of WS, <sup>182</sup>W<sup>32</sup>S, <sup>183</sup>W<sup>32</sup>S, <sup>184</sup>W<sup>32</sup>S, and <sup>186</sup>W<sup>32</sup>S, were measured and a rotational analysis was performed using PGOPHER. A constrained parameters approach was used to maintain expected mass relationships among isotopologues. This analysis increases the number of observed rotational levels from J ∼ 30 to J ∼ 100 for both excited states, allowing an increase in precision of spectroscopic constants. The new analysis of the [15.30]1 <strong>–</strong> <em>X</em> <sup>3</sup>Σ<sup>−</sup>(1) transition enabled the reduced uncertainty in the previously determined value for the splitting of the 0+ and 1 Ω-components of the <em>X</em> <sup>3</sup>Σ<sup>−</sup> ground state. Also presented in this work is an expansion upon our earlier deperturbation analysis involving the [15.30]1 state to include the v′ = 2 vibrational level, which is perturbed by the v′ = 4 vibrational level of the [14.26]0<sup>+</sup> state.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111999"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143201823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2025.111996
V.G. Ushakov, A.Yu. Ermilov, E.S. Medvedev
{"title":"Three-states model for calculating the X-X rovibrational transition intensities in hydroxyl radical (Erratum)","authors":"V.G. Ushakov, A.Yu. Ermilov, E.S. Medvedev","doi":"10.1016/j.jms.2025.111996","DOIUrl":"10.1016/j.jms.2025.111996","url":null,"abstract":"","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111996"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2025.111997
Lukas Meinschad , Kemal Oenen , Dennis F. Dinu , Klaus R. Liedl
The hydrogen bond (HB), a non-covalent interaction, leads to diverse structural motifs that dictate the physical properties of materials or biochemical processes. Infrared spectroscopy allows straightforward access to such structural motifs from laboratory experiments. These spectra indirectly reveal HBs through vibrational frequency shifts in a molecular cluster compared to the single molecules. Characterizing these shifts with descriptive vibrational notations is challenging due to the delocalized nature of intermolecular vibrations. Typically, vibrations of clusters are represented in terms of the respective individual molecules. This approach is somewhat debatable, mainly when notations are based on experience or visual interpretation of theoretical models, most notably the normal mode framework. While normal modes are straightforward to obtain, they often provide insufficient descriptions of delocalized vibrations. Here, the decomposition of normal modes into contributions from internal coordinates allows for both an illustrative framework and a quantitative basis for vibrational notations. In the present work, we apply such a decomposition scheme to various HB systems, assessing the plausibility of notations used in IR spectroscopy of molecular clusters. For water, methanol, and clusters thereof, we demonstrate the limitations of conventional notations and how normal mode decomposition schemes can provide a reasonable workaround.
{"title":"Toward less ambiguous vibrational spectroscopic notations for hydrogen-bonded water and methanol clusters","authors":"Lukas Meinschad , Kemal Oenen , Dennis F. Dinu , Klaus R. Liedl","doi":"10.1016/j.jms.2025.111997","DOIUrl":"10.1016/j.jms.2025.111997","url":null,"abstract":"<div><div>The hydrogen bond (HB), a non-covalent interaction, leads to diverse structural motifs that dictate the physical properties of materials or biochemical processes. Infrared spectroscopy allows straightforward access to such structural motifs from laboratory experiments. These spectra indirectly reveal HBs through vibrational frequency shifts in a molecular cluster compared to the single molecules. Characterizing these shifts with descriptive vibrational notations is challenging due to the delocalized nature of intermolecular vibrations. Typically, vibrations of clusters are represented in terms of the respective individual molecules. This approach is somewhat debatable, mainly when notations are based on experience or visual interpretation of theoretical models, most notably the normal mode framework. While normal modes are straightforward to obtain, they often provide insufficient descriptions of delocalized vibrations. Here, the decomposition of normal modes into contributions from <em>internal coordinates</em> allows for both an illustrative framework and a quantitative basis for vibrational notations. In the present work, we apply such a decomposition scheme to various HB systems, assessing the plausibility of notations used in IR spectroscopy of molecular clusters. For water, methanol, and clusters thereof, we demonstrate the limitations of conventional notations and how normal mode decomposition schemes can provide a reasonable workaround.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111997"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2024.111967
Luis Bonah , Benedikt Helmstaedter , Jean-Claude Guillemin , Stephan Schlemmer , Sven Thorwirth
Cyclopentadiene ( ) is a cyclic pure hydrocarbon that was already detected astronomically towards the prototypical dark cloud TMC-1 (Cernicharo et al., 2021). However, accurate predictions of its rotational spectrum are still limited to the microwave region and narrow quantum number ranges. In the present study, the pure rotational spectrum of cyclopentadiene was measured in the frequency ranges 170–250 GHz and 340–510 GHz to improve the number of vibrational ground state assignments by more than a factor of 20, resulting in more accurate rotational parameters and the determination of higher-order centrifugal distortion parameters. Additionally, vibrational satellite spectra of cyclopentadiene in its eight energetically lowest vibrationally excited states were analyzed for the first time. Coriolis interactions between selected vibrational states were identified and treated successfully in combined fits. Previous microwave work on the three singly substituted isotopologues was extended significantly also covering frequency ranges up to 250 GHz. The new data sets permit reliable frequency predictions for the isotopologues and vibrational satellite spectra far into the sub-mm-wave range. Finally, the experimental rotational constants of all available isotopologues and calculated zero-point vibrational contributions to the rotational constants were used to derive a semi-experimental equilibrium structure of this fundamental ring molecule.
环戊二烯（Cyclopentadiene）是一种环纯碳氢化合物，在天文学上已经探测到它靠近典型的黑云TMC-1 （Cernicharo et al., 2021）。然而，对其旋转谱的准确预测仍然局限于微波区和较窄的量子数范围。在本研究中，环戊二烯的纯旋转光谱在170-250 GHz和340-510 GHz频率范围内进行了测量，将振动基态分配的数量提高了20倍以上，从而获得了更精确的旋转参数和高阶离心畸变参数的确定。此外，首次分析了环戊二烯在其8个能量最低振动激发态下的振动卫星谱。选定的振动状态之间的科里奥利相互作用被识别并成功地在组合拟合中处理。以前对三种单取代同位素的微波工作已大大扩展，频率范围也达到250千兆赫。新的数据集允许对远至亚毫米波范围的同位素和振动卫星谱进行可靠的频率预测。最后，利用所有可用同位素的实验旋转常数和计算的零点振动对旋转常数的贡献，推导出该基本环分子的半实验平衡结构。
{"title":"Extending the rotational spectrum of cyclopentadiene towards higher frequencies and vibrational states","authors":"Luis Bonah , Benedikt Helmstaedter , Jean-Claude Guillemin , Stephan Schlemmer , Sven Thorwirth","doi":"10.1016/j.jms.2024.111967","DOIUrl":"10.1016/j.jms.2024.111967","url":null,"abstract":"<div><div>Cyclopentadiene ( <figure><img></figure> ) is a cyclic pure hydrocarbon that was already detected astronomically towards the prototypical dark cloud TMC-1 (Cernicharo et al., 2021). However, accurate predictions of its rotational spectrum are still limited to the microwave region and narrow quantum number ranges. In the present study, the pure rotational spectrum of cyclopentadiene was measured in the frequency ranges 170–250<!--> <!-->GHz and 340–510<!--> <!-->GHz to improve the number of vibrational ground state assignments by more than a factor of 20, resulting in more accurate rotational parameters and the determination of higher-order centrifugal distortion parameters. Additionally, vibrational satellite spectra of cyclopentadiene in its eight energetically lowest vibrationally excited states were analyzed for the first time. Coriolis interactions between selected vibrational states were identified and treated successfully in combined fits. Previous microwave work on the three singly <figure><img></figure> substituted isotopologues was extended significantly also covering frequency ranges up to 250<!--> <!-->GHz. The new data sets permit reliable frequency predictions for the isotopologues and vibrational satellite spectra far into the sub-mm-wave range. Finally, the experimental rotational constants of all available isotopologues and calculated zero-point vibrational contributions to the rotational constants were used to derive a semi-experimental equilibrium structure of this fundamental ring molecule.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111967"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.jms.2025.111985
Isiah M. McMurray, Joseph R. Nettles, Aaron W. Uzelmeier, Jeremy A. Swartz, Josh J. Newby
The weakly bound complexes of N-methyl-2-pyrrolidone (NMP) and water have been analyzed using a combination of computational methods and matrix isolation FTIR spectroscopy. The computational analysis utilized density functional and perturbation theory methods to determine the lowest energy geometries and vibrational frequencies of NMP: H2O. This analysis yielded four unique structures that could be differentiated by their preferred intermolecular interaction. Two structures formed via relatively strong OH⋯O hydrogen bonds, one structure was stabilized via OH⋯N interactions, and the fourth structure was observed to interact through relatively weak CH⋯O features. The interaction motifs were verified using atoms in molecules analysis and the noncovalent interaction index method. Spectra of NMP with H2O and its isotopologues showed clear evidence of two unique structures in the cryogenic nitrogen matrix. Both of these structures formed through OH⋯O interactions from the water to the carbonyl oxygen of NMP. This structural assignment was supported by the calculated vibrational shifts seen in NMP: H2O. A detailed analysis and discussion of this assignment is provided.
{"title":"An analysis of the N-methyl-2-pyrrolidone: water complex using computational and matrix isolation FTIR methods","authors":"Isiah M. McMurray, Joseph R. Nettles, Aaron W. Uzelmeier, Jeremy A. Swartz, Josh J. Newby","doi":"10.1016/j.jms.2025.111985","DOIUrl":"10.1016/j.jms.2025.111985","url":null,"abstract":"<div><div>The weakly bound complexes of <em>N</em>-methyl-2-pyrrolidone (NMP) and water have been analyzed using a combination of computational methods and matrix isolation FTIR spectroscopy. The computational analysis utilized density functional and perturbation theory methods to determine the lowest energy geometries and vibrational frequencies of NMP: H<sub>2</sub>O. This analysis yielded four unique structures that could be differentiated by their preferred intermolecular interaction. Two structures formed via relatively strong OH⋯O hydrogen bonds, one structure was stabilized via OH⋯N interactions, and the fourth structure was observed to interact through relatively weak CH⋯O features. The interaction motifs were verified using atoms in molecules analysis and the noncovalent interaction index method. Spectra of NMP with H<sub>2</sub>O and its isotopologues showed clear evidence of two unique structures in the cryogenic nitrogen matrix. Both of these structures formed through OH⋯O interactions from the water to the carbonyl oxygen of NMP. This structural assignment was supported by the calculated vibrational shifts seen in NMP: H<sub>2</sub>O. A detailed analysis and discussion of this assignment is provided.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"408 ","pages":"Article 111985"},"PeriodicalIF":1.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.jms.2024.111984
Shuo Zhao , Jie Gao , Yongqi Wu , Rui Zhu , Mu Li , Wanyi Qin , Xijun Wu , Yungang Zhang
Oxygen (O2) and ozone (O3) are of crucial importance to human health and environmental sustainability. Concentrations of O2 and O3 can be measured by UV absorption spectroscopy, in which the absorption cross-section (ACS) is a very critical physical parameter for calculating concentrations. However, the existing ACS of O2 and O3 are biased because the conversion of O2 to O3 and nonlinear effects in absorption are ignored in the measurement of ACS. In this study, the ACS for O2 and O3 are obtained by considering the conversion of O2 to O3 and the nonlinear effects. First, the conversion of O2 to O3 is inhibited by controlling gas flow rate and light intensity in the measurement of O2 and O3 ACS. Then the concentration of O3 is indirectly calculated by controlling conversion of O2 to O3 during the measurement of ACS of O3. Next, the linear-absorption regions for O2 and O3 are determined by constructing the relationship between absorption intensities and concentrations to eliminate the influence of nonlinear effect. The maximum ACS for oxygen and ozone are cm2/molecule ( = 180.51 nm) and cm2/molecule ( = 255.39 nm) by controlling conversion of O2 to O3 in the linear-absorption region, respectively.
{"title":"Measurement of O2 and O3 absorption cross-sections in the 180–270 nm by controlling the conversion of O2 to O3 in the linear-absorption region","authors":"Shuo Zhao , Jie Gao , Yongqi Wu , Rui Zhu , Mu Li , Wanyi Qin , Xijun Wu , Yungang Zhang","doi":"10.1016/j.jms.2024.111984","DOIUrl":"10.1016/j.jms.2024.111984","url":null,"abstract":"<div><div>Oxygen (O<sub>2</sub>) and ozone (O<sub>3</sub>) are of crucial importance to human health and environmental sustainability. Concentrations of O<sub>2</sub> and O<sub>3</sub> can be measured by UV absorption spectroscopy, in which the absorption cross-section (ACS) is a very critical physical parameter for calculating concentrations. However, the existing ACS of O<sub>2</sub> and O<sub>3</sub> are biased because the conversion of O<sub>2</sub> to O<sub>3</sub> and nonlinear effects in absorption are ignored in the measurement of ACS. In this study, the ACS for O<sub>2</sub> and O<sub>3</sub> are obtained by considering the conversion of O<sub>2</sub> to O<sub>3</sub> and the nonlinear effects. First, the conversion of O<sub>2</sub> to O<sub>3</sub> is inhibited by controlling gas flow rate and light intensity in the measurement of O<sub>2</sub> and O<sub>3</sub> ACS. Then the concentration of O<sub>3</sub> is indirectly calculated by controlling conversion of O<sub>2</sub> to O<sub>3</sub> during the measurement of ACS of O<sub>3</sub>. Next, the linear-absorption regions for O<sub>2</sub> and O<sub>3</sub> are determined by constructing the relationship between absorption intensities and concentrations to eliminate the influence of nonlinear effect. The maximum ACS for oxygen and ozone are <span><math><mrow><mn>7.84</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>-</mo><mn>20</mn></mrow></msup></mrow></math></span> cm<sup>2</sup>/molecule (<span><math><mrow><mi>λ</mi></mrow></math></span> = 180.51 nm) and <span><math><mrow><mn>1.32</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>-</mo><mn>17</mn></mrow></msup></mrow></math></span> cm<sup>2</sup>/molecule (<span><math><mrow><mi>λ</mi></mrow></math></span> = 255.39 nm) by controlling conversion of O<sub>2</sub> to O<sub>3</sub> in the linear-absorption region, respectively.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111984"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.jms.2024.111978
Carlo Baddeliyanage , Joshua Karner , Sruthi Purushu Melath , Weslley G.D.P. Silva , Stephan Schlemmer , Oskar Asvany
The rotational spectrum of linear CH has been revisited in the millimeter-wave region using a cryogenic ion trap apparatus employing a double-resonance scheme based on leak-out action spectroscopy (LOS). Eight rotational transitions ( up to ) have been measured in the 85-250GHz frequency range. With the laboratory measurements reported here, improved values for the ground-state spectroscopic constants of CH have been obtained.
{"title":"Extending the laboratory rotational spectrum of linear C3H+","authors":"Carlo Baddeliyanage , Joshua Karner , Sruthi Purushu Melath , Weslley G.D.P. Silva , Stephan Schlemmer , Oskar Asvany","doi":"10.1016/j.jms.2024.111978","DOIUrl":"10.1016/j.jms.2024.111978","url":null,"abstract":"<div><div>The rotational spectrum of linear C<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>H<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> has been revisited in the millimeter-wave region using a cryogenic ion trap apparatus employing a double-resonance scheme based on leak-out action spectroscopy (LOS). Eight rotational transitions (<span><math><mrow><msup><mrow><mi>J</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>←</mo><msup><mrow><mi>J</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup><mo>=</mo><mn>4</mn><mo>←</mo><mn>3</mn></mrow></math></span> up to <span><math><mrow><msup><mrow><mi>J</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>←</mo><msup><mrow><mi>J</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup><mo>=</mo><mn>11</mn><mo>←</mo><mn>10</mn></mrow></math></span>) have been measured in the 85-250<span><math><mspace></mspace></math></span>GHz frequency range. With the laboratory measurements reported here, improved values for the ground-state spectroscopic constants of C<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>H<span><math><msup><mrow></mrow><mrow><mo>+</mo></mrow></msup></math></span> have been obtained.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111978"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-01DOI: 10.1016/j.jms.2024.111979
Haiying Huang, Xiaolong Li, Gang Feng
We investigated the non-covalent interactions occurring between benzofuran and water. The weakly-bound complex was produced using a supersonic jet expansion and was subsequently characterized utilizing high-resolution Fourier transform microwave spectroscopy. Through the analysis of the rotational spectrum, we were able to confirm the detection of two distinct conformations within the complex. The most stable conformation demonstrates a structure that is almost coplanar. This structure involves one hydrogen atom from a water molecule interacting with the oxygen atom of benzofuran, thus forming an Ow–Hw···O hydrogen bond. Concurrently, the oxygen atom serves as a proton acceptor, forming an Ow···HC hydrogen bond with one hydrogen atom of the phenyl ring. The secondary conformation positions the two OH bonds such that they are oriented towards the face of benzofuran, resulting in the formation of two Ow–Hw···π hydrogen bonds. The non-covalent bonding topology of the first conformation bears resemblance to the corresponding furan-water complex, while the second conformation aligns with the benzofuran-hydrogen sulfide complex. The strength and the nature of these hydrogen bonding interactions is delineated by the application of natural bond orbital theory, energy decomposition, and electronic density analysis methodologies.
{"title":"Rotational spectroscopy of the benzofuran–water complex: Conformations and preferred noncovalent interactions","authors":"Haiying Huang, Xiaolong Li, Gang Feng","doi":"10.1016/j.jms.2024.111979","DOIUrl":"10.1016/j.jms.2024.111979","url":null,"abstract":"<div><div>We investigated the non-covalent interactions occurring between benzofuran and water. The weakly-bound complex was produced using a supersonic jet expansion and was subsequently characterized utilizing high-resolution Fourier transform microwave spectroscopy. Through the analysis of the rotational spectrum, we were able to confirm the detection of two distinct conformations within the complex. The most stable conformation demonstrates a structure that is almost coplanar. This structure involves one hydrogen atom from a water molecule interacting with the oxygen atom of benzofuran, thus forming an O<sub>w</sub>–H<sub>w</sub>···O hydrogen bond. Concurrently, the oxygen atom serves as a proton acceptor, forming an O<sub>w</sub>···H<img>C hydrogen bond with one hydrogen atom of the phenyl ring. The secondary conformation positions the two O<img>H bonds such that they are oriented towards the face of benzofuran, resulting in the formation of two O<sub>w</sub>–H<sub>w</sub>···π hydrogen bonds. The non-covalent bonding topology of the first conformation bears resemblance to the corresponding furan-water complex, while the second conformation aligns with the benzofuran-hydrogen sulfide complex. The strength and the nature of these hydrogen bonding interactions is delineated by the application of natural bond orbital theory, energy decomposition, and electronic density analysis methodologies.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111979"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号