Journal of Molecular Spectroscopy最新文献

{"title":"A new electronic transition of vanadium hydride: The C′5Δ–X5Δ (1,0) band","authors":"Kevin A. Tovar ,&nbsp;Thomas D. Varberg","doi":"10.1016/j.jms.2025.112051","DOIUrl":"10.1016/j.jms.2025.112051","url":null,"abstract":"<div><div>We report the observation and analysis of a new electronic transition in gas-phase vanadium hydride (VH), identified as the C′⁵Δ–X⁵Δ (1,0) band with an origin at 14,015 cm⁻¹ (714 nm). The spectrum was recorded by laser excitation spectroscopy, with laser-induced fluorescence detected to the X⁵Δ (<em>v</em> = 1) level. Dispersed fluorescence measurements enabled a detailed characterization of the vibrationally excited ground state, yielding a vibrational interval of Δ<em>G</em>_1/2 = 1606.6(2) cm⁻¹. Despite the presence of significant local perturbations—particularly in the Ω = 0 and 1 spin components of the C′⁵Δ state—a full rotational analysis of the spectrum using a Hund's case (a) Hamiltonian was achieved. Spectroscopic constants including rotational, spin–orbit, spin–rotation, and Λ-doubling parameters are reported for both the new C′⁵Δ state and the X⁵Δ (<em>v</em> = 1) level. Additionally, we observed a small local perturbation in the X⁵Δ₁ (<em>v</em> = 1) level near <em>J</em> = 9, attributed to homogeneous spin–orbit and heterogeneous L-uncoupling interactions with the previously analyzed A⁵Π (<em>v</em> = 0) state. An X⁵Δ ∼ A⁵Π coupled Hamiltonian was used to model this perturbation and yielded interaction parameters roughly consistent with semi-empirical estimates. This work represents only the second analyzed spectroscopic transition of gas-phase VH.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112051"},"PeriodicalIF":1.3,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105898","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}

{"title":"Measurements of the microwave spectrum and calculations of the molecular structure for η4-butadiene osmium tricarbonyl","authors":"Adam M. Daly ,&nbsp;Stephen G. Kukolich","doi":"10.1016/j.jms.2025.112050","DOIUrl":"10.1016/j.jms.2025.112050","url":null,"abstract":"<div><div>The microwave spectrum of η⁴-butadiene osmium tricarbonyl was measured in the 6–12 GHz frequency range using a Flygare-Balle type pulsed beam Fourier transform microwave (FTMW) spectrometer. The rotational constants for the ¹⁹²Os isotopologues were determined to have the following values: A = 939.4(2), B = 849.08(1) and C = 816.71(1) MHz. The centrifugal distortion constant is D_J = 0.60(7) kHz. 16 a-dipole transitions were measured and included in the fit. Extensive high-level G16 calculations were made using DFT methods with various basis sets, including core-potentials (ECP). The best structure was calculated with Gaussian 16 using B3LYP/def2-QZVPP, which includes a core potential (ECP). The best calculated values are in very good agreement with the experimental values.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112050"},"PeriodicalIF":1.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045681","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}

{"title":"Off-axis integrated cavity output spectroscopic study of 31112–01101 band of CO2 in 1.57 μm spectral region","authors":"Ayan Kumar Pal ,&nbsp;Naveen Kumar","doi":"10.1016/j.jms.2025.112049","DOIUrl":"10.1016/j.jms.2025.112049","url":null,"abstract":"<div><div>The near-infrared experimental investigation of greenhouse gases and their spectroscopic parameters finds a wide range of applications in the field of atmospheric science, astrophysics, and climate change research. Carbon dioxide (CO₂), an important greenhouse gas, has been the subject of various spectroscopic studies due to its pivotal role in climate change, as well as in the atmospheric and astrophysical sciences. In this study, we present the spectroscopic investigation of ro-vibrational lines of <em>P-</em> and <em>R-</em>branches of the weak 31112–01101 band (<em>f</em>-symmetry) of CO₂ lying in 1.57 μm spectral region. The study was carried out by high-sensitive off-axis integrated cavity output spectroscopy (OA-ICOS) coupled with a continuous wave-external cavity diode laser (CW-ECDL) source. The study focuses on the experimental measurement of vital spectroscopic parameters, such as air-broadening coefficients (γ_air), line intensities and self-broadening coefficients (γ_self) of various interference free lines (8 ≤ <em>J</em> ≤ 28) in the <em>P-</em> and <em>R-</em>branches of the hot band. The OA-ICOS absorption lines were modeled using the Voigt profile function to retrieve the parameters, which accurately reproduced the line shapes within the spectral noise level. The obtained γ_air were compared with empirical values present in HITRAN2020 and theoretical values in CDSD, showing mean discrepancies of about 3.20% and 1.25%, respectively. The retrieved line intensities and γ_self were also compared with previously reported values, revealing mean discrepancies of about 1.99% and 1.34%, respectively. Additionally, rotational dependency, the Einstein-<em>A</em>₂₁ coefficient, effective collision diameter and cross-sections for CO₂-CO₂ and CO₂-air binary systems have also been explored and presented. The molecular spectroscopic parameters retrieved in this study will find various applications in the field of atmospheric science, astrophysical science, and climate change research.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112049"},"PeriodicalIF":1.3,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045682","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}

{"title":"Rotational spectroscopy, quadrupole coupling and unusual quartic centrifugal distortion constants of 1,1-dichloro-1-silacyclopent-2-ene","authors":"Alexander R. Davies ,&nbsp;Nicole T. Moon ,&nbsp;Amanda J. Duerden ,&nbsp;Thomas M.C. McFadden ,&nbsp;Gamil A. Guirgis ,&nbsp;G.S. Grubbs II","doi":"10.1016/j.jms.2025.112038","DOIUrl":"10.1016/j.jms.2025.112038","url":null,"abstract":"<div><div>The ground state rotational spectrum of 1,1-dichloro-1-silacyclopent-2-ene has been recorded using chirped-pulse Fourier transform microwave spectroscopy. A planar ring-structure in the ground vibrational state is supported by the rotational spectrum, but particularly by the analysis of the sometimes-complicated hyperfine splitting and isotopic substitution. Furthermore, fitting the rotational spectrum to a Watson S-reduced Hamiltonian in the I^<em>r</em> representation yields a negative value of <em>D</em>_<em>J</em>, which is in agreement with quantum chemical calculation. In addition, the quadrupole coupling is considered and some structural information is presented — both compare well to expectations from other related systems and quantum chemical calculation.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112038"},"PeriodicalIF":1.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220800","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}

{"title":"Updated line list for the principal isotopologue of carbon monoxide","authors":"Vladimir G. Ushakov,&nbsp;Emile S. Medvedev","doi":"10.1016/j.jms.2025.112037","DOIUrl":"10.1016/j.jms.2025.112037","url":null,"abstract":"<div><div>The line list for the principal isotopologue of CO calculated earlier by the present authors (Medvedev, 2022), (Ushakov, 2022) with the irregular dipole-moment function (DMF) is updated with use of the recent high-precision measurements in the 3-0 (Bielska et al., 2022, Hodges et al., 2025) and 7-0 (Balashov et al., 2023) bands. The new data came in contradiction with the experimental data on the 1-0 band (Zou and Varanasi, 2002, Devi et al., 2018). Therefore, we performed fitting several model DMFs to the modified original data set of Meshkov et al. (2022) by including the new above-referenced data and by excluding the data for the 1-0 band. The updated line list is calculated with the irregular DMF. In particular, excellent agreement with recent high-level <em>ab initio</em> calculations on the 3-0 band (Bielska et al., 2022) is emphasized and predictions for the 1-0 and 8-0 bands are outlined. In the new update of the HITRAN database (Gordon et al., 2025) new high-precision measurements in the cold and hot fundamental bands are announced. When these data are published, they will be compared with the predictions of our new line list.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112037"},"PeriodicalIF":1.3,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895661","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}

{"title":"Investigating the temperature dependence of photoelectron spectra in KArn clusters: Insights into stable structures and spectroscopic properties","authors":"Slim Awali ,&nbsp;Salem Naili ,&nbsp;Jamila Dhiflaoui ,&nbsp;Hamid Berriche ,&nbsp;Abdelaziz Bouazizi","doi":"10.1016/j.jms.2025.112032","DOIUrl":"10.1016/j.jms.2025.112032","url":null,"abstract":"<div><div>In this article, we investigate the temperature dependence of the photoelectron spectrum of a potassium atom adsorbed on argon clusters <span><math><msub><mrow><mtext>Ar</mtext></mrow><mrow><mi>n</mi></mrow></msub></math></span> (n <span><math><mrow><mo>=</mo><mn>1</mn><mo>−</mo><mn>10</mn></mrow></math></span>). We employ a combined Monte Carlo (MC) method with basin-hopping global optimization to simulate the geometries of the argon clusters in the excited 4p state at temperature <span><math><mi>T</mi></math></span>. Our ab initio model utilizes appropriate pseudopotentials to replace the core electrons of <span><math><msup><mrow><mtext>K</mtext></mrow><mrow><mo>+</mo></mrow></msup></math></span> and all electrons of the argon atoms, along with core polarization potentials. Electronic energies and transition dipole moments are calculated for each selected geometry, enabling us to simulate the photoelectron spectrum. Our results highlight the significant impact of temperature on the spectral characteristics of photoelectrons emitted from the <span><math><mrow><mi>K</mi><mtext>Ar</mtext></mrow></math></span> system. At a temperature of 5 K, we observe that the stable structures better reproduce the experimental photoelectron spectra. As the temperature increases, we observe broadening and shifting of the spectral peaks, suggesting the successive evaporation of argon atoms. Additionally, the influence of spin–orbit coupling is examined, which may also affect the spectral features and the dynamics following excitation.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"413 ","pages":"Article 112032"},"PeriodicalIF":1.3,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916253","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}

{"title":"Calculated 14N2 16O line intensities using Radau coordinates and an accurate potential energy surface","authors":"Irina I. Mizus ,&nbsp;Mikhail A. Rogov ,&nbsp;Nikolai F. Zobov ,&nbsp;Roman I. Ovsyannikov ,&nbsp;Evgenii I. Lebedev ,&nbsp;Jonathan Tennyson ,&nbsp;Oleg L. Polyansky","doi":"10.1016/j.jms.2025.112034","DOIUrl":"10.1016/j.jms.2025.112034","url":null,"abstract":"<div><div>Line intensities of the <span><math><mrow><mn>14</mn><mtext>N</mtext><mn>2</mn></mrow></math></span> <span><math><mrow><mn>16</mn><mtext>O</mtext></mrow></math></span> molecule are calculated using the DVR3D nuclear-motion program suite. Recently, we (Mizus <em>et al.</em>, JQSRT, <strong>344</strong>, 109463 (2025)) presented a potential energy surface (PES) fitted to empirical energy levels with an accuracy close to 0.002 <span><math><msup><mrow><mtext>cm</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> and very accurate dipole moment surfaces (DMS) calculated <em>ab initio</em> using a MRCI (multi-reference configuration interactions) level of theory. However, these accurate PES and DMS did not yield uniformly accurate calculated line intensities: some transition intensities disagreed with the measured ones by orders of magnitude. Here we analyze the reasons for these inaccurately calculated line intensities and develop a spectroscopic model which gives consistently accurate intensity predictions. This improvement is based on a relative minor improvement in the accuracy of the PES, the need for which was highlighted by changing the internal coordinates used in the calculation from Jacobi to Radau. In particular, the new model predicts line intensities with close to experimental accuracy for those vibrational bands, namely (<span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>1</mn></mrow></msub><msub><mrow><mi>v</mi></mrow><mrow><mn>2</mn></mrow></msub><mi>ℓ</mi><msub><mrow><mi>v</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>) equals (5000), (4200), (3200) and (0112), whose intensities have been measured with sub-percent accuracy.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"411 ","pages":"Article 112034"},"PeriodicalIF":1.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144809614","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}

{"title":"Fourier-transform microwave spectroscopy of cyano-substituted vinoxy radicals","authors":"Masakazu Nakajima ,&nbsp;Yasuki Endo","doi":"10.1016/j.jms.2025.112035","DOIUrl":"10.1016/j.jms.2025.112035","url":null,"abstract":"<div><div>Pure rotational transitions of three isomers of the cyanovinoxy radical were observed by Fourier-transform microwave spectroscopy. Fine and hyperfine components observed in the spectra were fully analyzed to determine their precise molecular constants. Cyano-substitution effect on the electronic structure of the vinoxy radical is discussed based on the experimentally determined molecular constants.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"411 ","pages":"Article 112035"},"PeriodicalIF":1.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827694","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}

{"title":"Microwave spectra of jet-cooled bromo- and chloroacetic acids","authors":"Kenneth J. Koziol,&nbsp;Aaron J. Reynolds,&nbsp;Victor Drewanz,&nbsp;Luis R. Padilla Jr.,&nbsp;Kenneth R. Leopold","doi":"10.1016/j.jms.2025.112033","DOIUrl":"10.1016/j.jms.2025.112033","url":null,"abstract":"<div><div>Microwave spectra of jet-cooled bromoacetic acid (CH₂BrCOOH) and chloroacetic acid (CH₂ClCOOH) have been obtained. For bromoacetic acid, the observed spectra are definitively assigned to a conformer in which the C–Br bond is nearly perpendicular to the plane defined by the other heavy atoms. This differs from the conformer previously observed at room temperature in which the C–Br bond was found to be <em>in the plane</em>. MP2 and DFT calculations predict four stable conformations, and the observed form corresponds to that with the lowest calculated energy. Diagonal and off-diagonal elements of the ⁷⁹Br and ⁸¹Br nuclear quadrupole coupling tensors have been determined and are in good agreement with the calculations. Interestingly, previous room temperature work on chloroacetic acid also revealed the conformation in which the C–Cl bond is in-plane (i.e., analogous to the room temperature work on bromoacetic acid). Thus, to see if the same disparity exists between the conformers observed under room temperature and jet-cooled conditions, the spectrum of jet-cooled chloroacetic was also examined. In this case, the conformer observed in the jet was the <em>same</em> as that previously reported at room temperature (in-plane C–Cl bond). The spectroscopic constants obtained, however, are somewhat more accurate than those previously determined and are reported here. Due to the cooling in the supersonic expansion, the species observed in this work are likely the lowest-energy forms for both acids. Comparison with prior studies on fluoro-, chloro-, and bromoacetic acids highlights a complex conformational landscape for these systems.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"411 ","pages":"Article 112033"},"PeriodicalIF":1.4,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144653280","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}

{"title":"Exploring indole dimer structures at the band origin: A spectroscopic gas phase IR analysis","authors":"Saurabh Mishra","doi":"10.1016/j.jms.2025.112031","DOIUrl":"10.1016/j.jms.2025.112031","url":null,"abstract":"<div><div>Non-covalent interactions such as hydrogen bonding and π–π stacking are central to molecular architecture. This study investigates the indole dimer near the band origin at 35238 cm⁻¹ using IR-UV double resonance spectroscopy and DFT calculations. The IDIR spectrum shows a red-shifted N<img>H stretch at 3420 cm⁻¹, indicative of hydrogen bonding. Computational analyses with B97D and B3LYP-D3 functionals favor N–H‧‧‧π bonded structures. Among these, we assign a tilted geometry featuring N–H‧‧‧π interaction as the most consistent with experimental observations. The broad spectral profile also suggests the coexistence of multiple low-energy isomers.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"411 ","pages":"Article 112031"},"PeriodicalIF":1.4,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144611716","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}