Pub Date : 2025-03-01Epub Date: 2025-04-03DOI: 10.1016/j.jms.2025.112010
Wafaa M. Fawzy
<div><div>We report the first accurate global fits for the rotation-spin-tunneling transitions in the microwave spectrum of the O<sub>2</sub>(<span><math><mmultiscripts><msubsup><mi>Σ</mi><mi>g</mi><mo>−</mo></msubsup><mprescripts></mprescripts><mspace></mspace><mn>3</mn></mmultiscripts></math></span>)-SO<sub>2</sub> (<sup>1</sup>A<sub>1</sub>) weakly bonded open-shell complex. In addition, we present a new ab initio investigation of the potential energy surface of O<sub>2</sub>(<span><math><mmultiscripts><msubsup><mi>Σ</mi><mi>g</mi><mo>−</mo></msubsup><mprescripts></mprescripts><mspace></mspace><mn>3</mn></mmultiscripts></math></span>)-SO<sub>2</sub>, using the UCCSD(T)/aug-cc-pV(n + d)Z level of theory where <em>n</em> = 2 and 3. Analysis of the spectrum identified a-type and c-type transitions, frequencies of the a-type were not shifted while those of the c-type were shifted due to tunneling of the O<sub>2</sub> and the SO<sub>2</sub> moieties in the dimer. Only the A<sub>1</sub> symmetric tunneling state was detected because the antisymmetric A<sub>2</sub> state is not allowed by nuclear spin statistics in O<sub>2</sub>-SO<sub>2</sub>. Least squares fits with a standard deviation of 1 kHz were obtained using two computer codes incorporating semi-rigid rotor Hamiltonians that employ two different angular momenta coupling schemes. Results of the fits determined the effective tunneling frequency in the A<sub>1</sub> symmetric state as <span><math><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>= 2373.61134 <span><math><mo>±</mo></math></span>16 MHz, the electron spin coupling constant λ = 42,870.2186 <span><math><mo>±</mo></math></span>43 MHz, the rotational constants A = 7099.44 <span><math><mo>±</mo></math></span>33, B = 1528.886 <span><math><mo>±</mo></math></span>5, C = 1763.36 <span><math><mo>±</mo></math></span>6 MHz. The value of <span><math><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span> equals the tunneling splitting (<span><math><msub><mi>Δ</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>) between the<span><math><msubsup><mi>A</mi><mn>1</mn><mo>+</mo></msubsup></math></span> and <span><math><msubsup><mi>A</mi><mn>1</mn><mo>−</mo></msubsup></math></span> symmetric tunneling states in the dimer, where the<span><math><msubsup><mi>A</mi><mn>1</mn><mo>+</mo></msubsup></math></span> and <span><math><msubsup><mi>A</mi><mn>1</mn><mo>−</mo></msubsup></math></span> levels are shifted in energy by <span><math><mo>−</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span> and <span><math><mo>+</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>, respectively. The ab initio study identified a global minimum energy structure of C<sub>1</sub> symmetry and a metastable local minimum of C<sub>s</sub> symmetry. We computed the optimized geometries of four equivalent configurations in the m
{"title":"New spectroscopic fits and ab initio study of the O2(Σg−3)-SO2 (1A1) open-shell dimer","authors":"Wafaa M. Fawzy","doi":"10.1016/j.jms.2025.112010","DOIUrl":"10.1016/j.jms.2025.112010","url":null,"abstract":"<div><div>We report the first accurate global fits for the rotation-spin-tunneling transitions in the microwave spectrum of the O<sub>2</sub>(<span><math><mmultiscripts><msubsup><mi>Σ</mi><mi>g</mi><mo>−</mo></msubsup><mprescripts></mprescripts><mspace></mspace><mn>3</mn></mmultiscripts></math></span>)-SO<sub>2</sub> (<sup>1</sup>A<sub>1</sub>) weakly bonded open-shell complex. In addition, we present a new ab initio investigation of the potential energy surface of O<sub>2</sub>(<span><math><mmultiscripts><msubsup><mi>Σ</mi><mi>g</mi><mo>−</mo></msubsup><mprescripts></mprescripts><mspace></mspace><mn>3</mn></mmultiscripts></math></span>)-SO<sub>2</sub>, using the UCCSD(T)/aug-cc-pV(n + d)Z level of theory where <em>n</em> = 2 and 3. Analysis of the spectrum identified a-type and c-type transitions, frequencies of the a-type were not shifted while those of the c-type were shifted due to tunneling of the O<sub>2</sub> and the SO<sub>2</sub> moieties in the dimer. Only the A<sub>1</sub> symmetric tunneling state was detected because the antisymmetric A<sub>2</sub> state is not allowed by nuclear spin statistics in O<sub>2</sub>-SO<sub>2</sub>. Least squares fits with a standard deviation of 1 kHz were obtained using two computer codes incorporating semi-rigid rotor Hamiltonians that employ two different angular momenta coupling schemes. Results of the fits determined the effective tunneling frequency in the A<sub>1</sub> symmetric state as <span><math><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>= 2373.61134 <span><math><mo>±</mo></math></span>16 MHz, the electron spin coupling constant λ = 42,870.2186 <span><math><mo>±</mo></math></span>43 MHz, the rotational constants A = 7099.44 <span><math><mo>±</mo></math></span>33, B = 1528.886 <span><math><mo>±</mo></math></span>5, C = 1763.36 <span><math><mo>±</mo></math></span>6 MHz. The value of <span><math><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span> equals the tunneling splitting (<span><math><msub><mi>Δ</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>) between the<span><math><msubsup><mi>A</mi><mn>1</mn><mo>+</mo></msubsup></math></span> and <span><math><msubsup><mi>A</mi><mn>1</mn><mo>−</mo></msubsup></math></span> symmetric tunneling states in the dimer, where the<span><math><msubsup><mi>A</mi><mn>1</mn><mo>+</mo></msubsup></math></span> and <span><math><msubsup><mi>A</mi><mn>1</mn><mo>−</mo></msubsup></math></span> levels are shifted in energy by <span><math><mo>−</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span> and <span><math><mo>+</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><msub><mi>ν</mi><msub><mi>T</mi><mn>1</mn></msub></msub></math></span>, respectively. The ab initio study identified a global minimum energy structure of C<sub>1</sub> symmetry and a metastable local minimum of C<sub>s</sub> symmetry. We computed the optimized geometries of four equivalent configurations in the m","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 112010"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820648","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 : 2025-03-01Epub Date: 2025-03-17DOI: 10.1016/j.jms.2025.112007
G.M. Chenard , A.G. Adam , D.W. Tokaryk , C. Linton
Laser Induced Fluorescence has been used to study the spectroscopy of Ruthenium Monoxide (RuO) in the UNB laser-ablation molecular-jet apparatus. High-resolution spectra of six bands from four previously obtained electronic transitions, [16.05]5 – X5Δ4, [16.19]4 - X5Δ4, [16.19]4 - X5Δ3 and [15.07]3 - X5Δ4 plus two previously unobserved transitions, [15.70]3 and [16.36]3 – X5Δ4, were obtained at a resolution 20 times higher than previous experiments. This enabled rotational structure of six individual RuO isotopologues, 96RuO, 99RuO, 100RuO, 101RuO, 102RuO and 104RuO to be well resolved and was used to examine detailed rotational and vibrational isotope effects. Hyperfine structure due to the nuclear spin I = 5/2 of 99Ru and 101Ru has also been well resolved and was a valuable aid in establishing the electron configurations of the electronic states. The difference in the hyperfine structure in the [16.05]5 and [16.19]4 states supported their assignment as the Ω = 5 and 4 spin orbit components, 5Φ5 and 5Φ4, of a single Hund's case (a) electronic state.
{"title":"Analysis of the rotational and hyperfine structure in the ‘red’ bands of ruthenium monoxide (RuO)","authors":"G.M. Chenard , A.G. Adam , D.W. Tokaryk , C. Linton","doi":"10.1016/j.jms.2025.112007","DOIUrl":"10.1016/j.jms.2025.112007","url":null,"abstract":"<div><div>Laser Induced Fluorescence has been used to study the spectroscopy of Ruthenium Monoxide (RuO) in the UNB laser-ablation molecular-jet apparatus. High-resolution spectra of six bands from four previously obtained electronic transitions, [16.05]5 – X<sup>5</sup>Δ<sub>4</sub>, [16.19]4 - X<sup>5</sup>Δ<sub>4</sub>, [16.19]4 - X<sup>5</sup>Δ<sub>3</sub> and [15.07]3 - X<sup>5</sup>Δ<sub>4</sub> plus two previously unobserved transitions, [15.70]3 and [16.36]3 – X<sup>5</sup>Δ<sub>4</sub>, were obtained at a resolution 20 times higher than previous experiments. This enabled rotational structure of six individual RuO isotopologues, <sup>96</sup>RuO, <sup>99</sup>RuO, <sup>100</sup>RuO, <sup>101</sup>RuO, <sup>102</sup>RuO and <sup>104</sup>RuO to be well resolved and was used to examine detailed rotational and vibrational isotope effects. Hyperfine structure due to the nuclear spin <em>I</em> = 5/2 of <sup>99</sup>Ru and <sup>101</sup>Ru has also been well resolved and was a valuable aid in establishing the electron configurations of the electronic states. The difference in the hyperfine structure in the [16.05]5 and [16.19]4 states supported their assignment as the Ω = 5 and 4 spin orbit components, <sup>5</sup>Φ<sub>5</sub> and <sup>5</sup>Φ<sub>4</sub>, of a single Hund's case (a) electronic state.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 112007"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746746","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 : 2025-03-01Epub Date: 2025-03-29DOI: 10.1016/j.jms.2025.112008
Wafaa M. Fawzy
We developed new FORTRAN codes that employ two different Hamiltonians [Wafaa M. Fawzy, J. Mol. Spectrosc., 397, 111,822, 2023] for calculation of energy levels and relative intensities of rotational transitions in an asymmetric or a symmetric top weakly-bonded open-shell dimer. The type of complexes of interest consist of a polyatomic/diatomic closed-shell molecule and the O2 diradical in its ground electronic state, where the monomers experience rotation-tunneling motion. The programs set up the Hamiltonian matrix considering pure rotation, quartic and sextic centrifugal distortion terms, electron-spin electron-spin coupling, R-dependence of electron-spin constants, electron-spin-rotation interaction, a symmetry treatment for rotation-tunneling of the monomers, and dependence of the rotational constants on the rotation-tunneling state. Numerical diagonalization of the total Hamiltonian matrix in the molecular basis set provides the eigenvalues and the eigenfunctions. The eigenfunctions are used to transform expectation values of the parity, five quantum numbers (<P>, <K>, <N>, <Ps>, <Σ>), and the electric dipole moment matrix elements from the Hamiltonian basis set to the eigenfunctions basis of the complex. Calculations showed that goodness of the quantum numbers depends on geometry and relative values of the electron–spin electron–spin coupling constants, the rotational parameters, the tunneling splitting. We used the Hellman–Feynman theory for calculation of derivatives of the eigenvalues with respect to molecular parameters, which significantly reduces the computer time for the non-linear least squares fits of transitions. The FORTRAN suites of computer programs were tested and validated by fitting the high resolution IR and MW spectra of the O2–DF and the O2-SO2 dimers, respectively, with standard deviations within accuracy of the frequency measurement. However, the codes should be suitable for spectral analysis of any O2 -XY2 or O2 -XY cluster, where XY2 and XY represent a closed-shell non-linear triatomic molecule of C2v symmetry (e.g. H2O) and a diatomic entity (e.g. CO), respectively. The FORTRAN source programs, input and output files for spectral fits of the MW spectrum of O2-SO2 are discussed. In addition, zipped files of the suites of programs, the input and output files for fitting the MW spectrum of O2-SO2 and the IR spectrum of O2 -DF, respectively, are provided as supplements that can be downloaded.
我们开发了新的FORTRAN代码，使用两种不同的哈密顿量[Wafaa M. Fawzy， J. Mol. Spectrosc]。计算非对称或对称顶部弱键开壳二聚体的能级和旋转跃迁的相对强度[j]，[397, 111,822, 2023]。这种类型的配合物由一个多原子/双原子闭壳分子和处于基电子态的O2双自由基组成，其中单体经历了旋转隧道运动。程序建立了考虑纯旋转、四次和六次离心畸变项、电子-自旋耦合、电子-自旋常数的r依赖性、电子-自旋-自旋相互作用、单体旋转隧穿的对称处理以及旋转常数对旋转隧穿态的依赖性的哈密顿矩阵。对分子基集中的总哈密顿矩阵进行数值对角化，得到了特征值和特征函数。本征函数用于将宇称、五个量子数（<P>, <K>, <N>, <Ps>, <；Σ>）和电偶极矩矩阵元素的期望值从哈密顿基集合转换为复合体的本征函数基。计算表明，量子数的优劣取决于几何形状和电子-自旋耦合常数、旋转参数、隧穿分裂的相对值。我们使用Hellman-Feynman理论计算特征值相对于分子参数的导数，这大大减少了非线性最小二乘拟合过渡的计算机时间。通过拟合O2-DF和O2-SO2二聚体的高分辨率IR和MW光谱，在频率测量精度的标准偏差范围内，对FORTRAN计算机程序套件进行了测试和验证。然而，这些代码应该适用于任何O2 -XY2或O2 -XY簇的光谱分析，其中XY2和XY分别代表C2v对称的闭壳非线性三原子分子（例如H2O）和双原子实体（例如CO）。讨论了用于O2-SO2的MW谱拟合的FORTRAN源程序、输入和输出文件。此外，还提供了程序套件的压缩文件、O2- so2的MW谱拟合输入文件和O2 -DF的IR谱拟合输出文件作为补充，可供下载。
{"title":"Two codes for calculation of the rotation-spin-tunneling energy levels in the microwave and the infrared spectra of O2 (Σg-3)-XY2 open-shell complexes","authors":"Wafaa M. Fawzy","doi":"10.1016/j.jms.2025.112008","DOIUrl":"10.1016/j.jms.2025.112008","url":null,"abstract":"<div><div>We developed new FORTRAN codes that employ two different Hamiltonians [Wafaa M. Fawzy, J. Mol. Spectrosc., 397, 111,822, 2023] for calculation of energy levels and relative intensities of rotational transitions in an asymmetric or a symmetric top weakly-bonded open-shell dimer. The type of complexes of interest consist of a polyatomic/diatomic closed-shell molecule and the O<sub>2</sub> diradical in its ground electronic state, where the monomers experience rotation-tunneling motion. The programs set up the Hamiltonian matrix considering pure rotation, quartic and sextic centrifugal distortion terms, electron-spin electron-spin coupling, R-dependence of electron-spin constants, electron-spin-rotation interaction, a symmetry treatment for rotation-tunneling of the monomers, and dependence of the rotational constants on the rotation-tunneling state. Numerical diagonalization of the total Hamiltonian matrix in the molecular basis set provides the eigenvalues and the eigenfunctions. The eigenfunctions are used to transform expectation values of the parity, five quantum numbers (<P>, <K>, <N>, <P<sub>s</sub>>, <Σ>), and the electric dipole moment matrix elements from the Hamiltonian basis set to the eigenfunctions basis of the complex. Calculations showed that goodness of the quantum numbers depends on geometry and relative values of the electron–spin electron–spin coupling constants, the rotational parameters, the tunneling splitting. We used the Hellman–Feynman theory for calculation of derivatives of the eigenvalues with respect to molecular parameters, which significantly reduces the computer time for the non-linear least squares fits of transitions. The FORTRAN suites of computer programs were tested and validated by fitting the high resolution IR and MW spectra of the O<sub>2</sub>–DF and the O<sub>2</sub>-SO<sub>2</sub> dimers, respectively, with standard deviations within accuracy of the frequency measurement. However, the codes should be suitable for spectral analysis of any O<sub>2</sub> -XY<sub>2</sub> or O<sub>2</sub> -XY cluster, where XY<sub>2</sub> and XY represent a closed-shell non-linear triatomic molecule of C<sub>2</sub>v symmetry (e.g. H<sub>2</sub>O) and a diatomic entity (e.g. CO), respectively. The FORTRAN source programs, input and output files for spectral fits of the MW spectrum of O<sub>2</sub>-SO<sub>2</sub> are discussed. In addition, zipped files of the suites of programs, the input and output files for fitting the MW spectrum of O<sub>2</sub>-SO<sub>2</sub> and the IR spectrum of O<sub>2</sub> -DF, respectively, are provided as supplements that can be downloaded.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 112008"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817609","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 : 2025-03-01Epub Date: 2025-04-01DOI: 10.1016/j.jms.2025.112009
Casper Vindahl Jensen, Emil Vogt, Henrik G. Kjaergaard
We have recorded gas-phase room-temperature absorption spectra of t-BuOOH in the OH-stretching regions, , using a combination of Fourier transform infrared spectroscopy and cavity ring-down spectroscopy. The t-BuOOH samples are phase-extracted into dichloromethane, which can be accurately accounted for by spectral subtraction. We thereby obtain spectra of pure t-BuOOH and corresponding sample partial pressures allowing us to obtain absolute intensities of the OH-stretching bands in all regions. The subtraction of solvents and impurities provides accurate values for the band intensities and positions. A reduced dimensional local mode model is invoked to corroborate the experimentally determined band oscillator strengths and their assignments. The fundamental OH-stretching band oscillator strength is determined to be about twice as large as the literature value. In the region, the intensity is spread out efficiently by a Franck–Condon-like mechanism to combination features associated with the OH-stretch and the COOH-torsion.
{"title":"Oscillator strengths of the fundamental and overtone OH-stretching bands of tert-butyl hydroperoxide in gas phase","authors":"Casper Vindahl Jensen, Emil Vogt, Henrik G. Kjaergaard","doi":"10.1016/j.jms.2025.112009","DOIUrl":"10.1016/j.jms.2025.112009","url":null,"abstract":"<div><div>We have recorded gas-phase room-temperature absorption spectra of <em>t</em>-BuOOH in the OH-stretching regions, <span><math><mrow><mi>Δ</mi><msub><mrow><mi>v</mi></mrow><mrow><mi>O</mi><mi>H</mi></mrow></msub><mo>=</mo><mn>1</mn><mo>−</mo><mn>5</mn></mrow></math></span>, using a combination of Fourier transform infrared spectroscopy and cavity ring-down spectroscopy. The <em>t</em>-BuOOH samples are phase-extracted into dichloromethane, which can be accurately accounted for by spectral subtraction. We thereby obtain spectra of pure <em>t</em>-BuOOH and corresponding sample partial pressures allowing us to obtain absolute intensities of the OH-stretching bands in all regions. The subtraction of solvents and impurities provides accurate values for the band intensities and positions. A reduced dimensional local mode model is invoked to corroborate the experimentally determined band oscillator strengths and their assignments. The fundamental OH-stretching band oscillator strength is determined to be <span><math><mrow><mrow><mo>(</mo><mn>4</mn><mo>.</mo><mn>56</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>15</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></math></span> about twice as large as the literature value. In the <span><math><mrow><mi>Δ</mi><msub><mrow><mi>v</mi></mrow><mrow><mi>O</mi><mi>H</mi></mrow></msub><mo>=</mo><mn>5</mn></mrow></math></span> region, the intensity is spread out efficiently by a Franck–Condon-like mechanism to combination features associated with the OH-stretch and the COOH-torsion.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 112009"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143776793","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 : 2025-03-01Epub Date: 2025-03-27DOI: 10.1016/j.jms.2025.112006
Tokio Yukiya, Shinji Kobayashi, Katsuki Nomura, Nobuo Nishimiya
Doppler-limited vibrational absorption spectra of the AX electronic transition of IBr are measured in the 0.695 – and the 0.90 – region using a Ti:sapphire ring laser. The absorption lines belonging to (0,1) and (6,7) for IBr are assigned, and the center position of the branch line belonging to over =21, which is split into a doublet by the electric quadrupole coupling effect, was estimated. The potential models and function parameters for the and states in IBr were determined using direct potential fitting.
{"title":"Direct potential fitting analysis for the A3Π1←X1Σ+ system of IBr","authors":"Tokio Yukiya, Shinji Kobayashi, Katsuki Nomura, Nobuo Nishimiya","doi":"10.1016/j.jms.2025.112006","DOIUrl":"10.1016/j.jms.2025.112006","url":null,"abstract":"<div><div>Doppler-limited vibrational absorption spectra of the <em>A</em> <span><math><mo>←</mo></math></span> <em>X</em> electronic transition of I<span><math><msup><mrow></mrow><mrow><mn>79</mn><mo>/</mo><mn>81</mn></mrow></msup></math></span>Br are measured in the 0.695 – <span><math><mrow><mn>0</mn><mo>.</mo><mn>735</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> and the 0.90 – <span><math><mrow><mn>0</mn><mo>.</mo><mn>94</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> region using a Ti:sapphire ring laser. The absorption lines belonging to <span><math><mrow><msup><mrow><mi>v</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>←</mo><msup><mrow><mi>v</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup><mo>=</mo><msup><mrow><mrow><mo>(</mo><mn>19</mn><mo>−</mo><mn>32</mn><mo>)</mo></mrow></mrow><mrow><mo>′</mo></mrow></msup></mrow></math></span> <span><math><mo>←</mo></math></span> (0,1)<span><math><msup><mrow></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup></math></span> and <span><math><msup><mrow><mrow><mo>(</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>,</mo><mn>4</mn><mo>)</mo></mrow></mrow><mrow><mo>′</mo></mrow></msup></math></span> <span><math><mo>←</mo></math></span> (6,7)<span><math><msup><mrow></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup></math></span> for I<span><math><msup><mrow></mrow><mrow><mn>79</mn><mo>/</mo><mn>81</mn></mrow></msup></math></span>Br are assigned, and the center position of the <span><math><mi>Q</mi></math></span> branch line belonging to over <span><math><msup><mrow><mi>v</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span>=21, which is split into a doublet by the electric quadrupole coupling effect, was estimated. The potential models and function parameters for the <span><math><mrow><msup><mrow><mi>A</mi></mrow><mrow><mn>3</mn></mrow></msup><msub><mrow><mi>Π</mi></mrow><mrow><mn>1</mn></mrow></msub></mrow></math></span> and <span><math><mrow><msup><mrow><mi>X</mi></mrow><mrow><mn>1</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math></span> states in I<span><math><msup><mrow></mrow><mrow><mn>79</mn><mo>/</mo><mn>81</mn></mrow></msup></math></span>Br were determined using direct potential fitting.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"409 ","pages":"Article 112006"},"PeriodicalIF":1.4,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799037","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 : 2025-03-01Epub Date: 2025-02-25DOI: 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 : 2025-02-01Epub Date: 2025-01-22DOI: 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 : 2025-02-01Epub Date: 2025-01-22DOI: 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 : 2025-02-01Epub Date: 2025-01-27DOI: 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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：