Pub Date : 2025-01-01DOI: 10.1016/j.jms.2024.111977
V.G. Ushakov , A. Yu. Ermilov , E.S. Medvedev
<div><div>The best available line list of OH [Brooke et al. JQSRT, 168 (2016) 142] contains the high-quality line frequencies, yet the line intensities need refinement because the model function used to interpolate the RKR potential and to extrapolate it into the repulsion region was not analytic [Medvedev et al. Mol. Phys. doi: 10.1080/00268976.2024.2395439], and also because the coupling between the ground <span><math><mrow><msup><mrow><mi>X</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>Π</mi></mrow></math></span> and first excited <span><math><mrow><msup><mrow><mi>A</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math></span> electronic states was treated by the perturbation theory. In this paper, we performed <em>ab initio</em> calculations of all necessary molecular functions at <span><math><mrow><mi>r</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>-8.0 bohr, and then we construct fully analytic model functions entering the Hamiltonian. The model functions were fitted to both the <em>ab initio</em> data and the available experimental data on the line positions and energy levels, the relative line intensities, and the transition dipole moments derived from the measured permanent dipoles. The system of three coupled Schrödinger equations for two multiplet components of the <span><math><mi>X</mi></math></span> state plus the <span><math><mi>A</mi></math></span> state was solved to calculate the energy levels and the line intensities. The new set of the Einstein <em>A</em> coefficients permits to decrease the scatter of the logarithmic populations of the ro-vibrational levels derived from the observed radiation fluxes [Noll et al. Atmos. Chem. Phys. 20 (2020) 5269], to achieve better agreement with the measured relative intensities, and to obtain significant differences in the intensities of the <span><math><mi>Λ</mi></math></span> doublets for large <span><math><mi>v</mi></math></span> and <span><math><mi>J</mi></math></span> as observed by Noll et al. The <span><math><mi>X</mi></math></span>-<span><math><mi>A</mi></math></span> coupling fully modifies the Q-line intensities at high <span><math><mi>J</mi></math></span> by removing the well-known <span><math><msup><mrow><mi>J</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span> dependence. A new line list is constructed where the transition frequencies are from Brooke et al. and the Einstein <span><math><mi>A</mi></math></span> coefficients are from the present study. However, not all the problems with the intensities were resolved, presumably due to the neglect of the interaction with the <span><math><mrow><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>,</mo></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math></span> and <span><math><mrow><msup><mrow></mrow><mrow><mn>4</mn
{"title":"Three-states model for calculating the X-X rovibrational transition intensities in hydroxyl radical","authors":"V.G. Ushakov , A. Yu. Ermilov , E.S. Medvedev","doi":"10.1016/j.jms.2024.111977","DOIUrl":"10.1016/j.jms.2024.111977","url":null,"abstract":"<div><div>The best available line list of OH [Brooke et al. JQSRT, 168 (2016) 142] contains the high-quality line frequencies, yet the line intensities need refinement because the model function used to interpolate the RKR potential and to extrapolate it into the repulsion region was not analytic [Medvedev et al. Mol. Phys. doi: 10.1080/00268976.2024.2395439], and also because the coupling between the ground <span><math><mrow><msup><mrow><mi>X</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>Π</mi></mrow></math></span> and first excited <span><math><mrow><msup><mrow><mi>A</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math></span> electronic states was treated by the perturbation theory. In this paper, we performed <em>ab initio</em> calculations of all necessary molecular functions at <span><math><mrow><mi>r</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>4</mn></mrow></math></span>-8.0 bohr, and then we construct fully analytic model functions entering the Hamiltonian. The model functions were fitted to both the <em>ab initio</em> data and the available experimental data on the line positions and energy levels, the relative line intensities, and the transition dipole moments derived from the measured permanent dipoles. The system of three coupled Schrödinger equations for two multiplet components of the <span><math><mi>X</mi></math></span> state plus the <span><math><mi>A</mi></math></span> state was solved to calculate the energy levels and the line intensities. The new set of the Einstein <em>A</em> coefficients permits to decrease the scatter of the logarithmic populations of the ro-vibrational levels derived from the observed radiation fluxes [Noll et al. Atmos. Chem. Phys. 20 (2020) 5269], to achieve better agreement with the measured relative intensities, and to obtain significant differences in the intensities of the <span><math><mi>Λ</mi></math></span> doublets for large <span><math><mi>v</mi></math></span> and <span><math><mi>J</mi></math></span> as observed by Noll et al. The <span><math><mi>X</mi></math></span>-<span><math><mi>A</mi></math></span> coupling fully modifies the Q-line intensities at high <span><math><mi>J</mi></math></span> by removing the well-known <span><math><msup><mrow><mi>J</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span> dependence. A new line list is constructed where the transition frequencies are from Brooke et al. and the Einstein <span><math><mi>A</mi></math></span> coefficients are from the present study. However, not all the problems with the intensities were resolved, presumably due to the neglect of the interaction with the <span><math><mrow><msup><mrow></mrow><mrow><mn>4</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo>,</mo></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mi>Σ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math></span> and <span><math><mrow><msup><mrow></mrow><mrow><mn>4</mn","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111977"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171321","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}
The rotational spectrum of 2’-aminoacetophenone has been recorded and assigned using a Stark-modulated Free-Jet Absorption Millimeter-Wave (FJ-AMMW) spectrometer in the 59.6–74.4 GHz frequency range. Some transition lines show a hyperfine structure due to the internal rotation of the methyl group. A global fitting including previous measurements performed in the microwave region allowed the determination of the and quartic centrifugal distortion constants and methyl internal rotation barrier = 644(3) cm−1 value. The A–E tunnelling splitting is estimated to be = 23 MHz. Calculations at the MP2/aug-cc-pVTZ level underestimate the height of the barrier by about 23 cm−1. This difference increases to 150 cm−1 with B3LYP-D3(BJ)/Def2-TZVP.
{"title":"Free-jet absorption millimeter-wave spectrum of 2’-aminoacetophenone","authors":"Salvatore Boi , Sonia Melandri , Luca Evangelisti , Assimo Maris","doi":"10.1016/j.jms.2024.111966","DOIUrl":"10.1016/j.jms.2024.111966","url":null,"abstract":"<div><div>The rotational spectrum of 2’-aminoacetophenone has been recorded and assigned using a Stark-modulated Free-Jet Absorption Millimeter-Wave (FJ-AMMW) spectrometer in the 59.6–74.4 GHz frequency range. Some transition lines show a hyperfine structure due to the internal rotation of the methyl group. A global fitting including previous measurements performed in the microwave region allowed the determination of the <span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>J</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>K</mi></mrow></msub></math></span> quartic centrifugal distortion constants and methyl internal rotation barrier <span><math><msub><mrow><mi>V</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> = 644(3) cm<sup>−1</sup> value. The A–E tunnelling splitting is estimated to be <span><math><msub><mrow><mi>Δ</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> = 23 MHz. Calculations at the MP2/aug-cc-pVTZ level underestimate the height of the <span><math><msub><mrow><mi>V</mi></mrow><mrow><mn>3</mn></mrow></msub></math></span> barrier by about 23 cm<sup>−1</sup>. This difference increases to 150 cm<sup>−1</sup> with B3LYP-D3(BJ)/Def2-TZVP.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111966"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171334","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.2024.111965
Leonid N. Sinitsa , Nikolai F. Zobov , Mikhail A. Rogov , Jonathan Tennyson , Oleg L. Polyansky
A spectrum of HD17O in the region between 5 480 and 6 400 recorded in Tomsk is reported. In this region 4292 lines are observed belonging to 7 water isotopologues: 536 lines – HO 1019 – HD16O, 122 – D O, 447 – HO 458 – HD17O, 151 – HO, 181 – HD18O. A new potential energy surface (PES) of HD16O is obtained by fitting to empirical energy levels. This PES, with a diagonal Born–Oppenheimer correction (DBOC), is used to compute the HD17O spectrum. Pseudo-experimental isotopologue-extrapolation energy levels of HD17O are constructed using the method of Polyansky et al (MNRAS 466, 1363 (2017)). Assignment of the measured spectrum is conducted: 68 % of the lines can be assigned using assignments from previously published work. The remaining lines are assigned using the pseudo-experimental energy levels procedure. We compare the calculated pseudo-experimental values of energy levels with both existing 1285 experimental levels of HD17O and the 152 newly determined in this work energy levels. The standard deviation of levels with low J (up to J=10) is about 0.007 in both cases. Energy levels from both pseudo-experimental and variationally calculated are also compared with newly measured HD17O lines above 10 000 .
{"title":"Study of HD17O spectrum. Theory and experiment","authors":"Leonid N. Sinitsa , Nikolai F. Zobov , Mikhail A. Rogov , Jonathan Tennyson , Oleg L. Polyansky","doi":"10.1016/j.jms.2024.111965","DOIUrl":"10.1016/j.jms.2024.111965","url":null,"abstract":"<div><div>A spectrum of HD<sup>17</sup>O in the region between 5 480 and 6 400 <span><math><msup><mrow><mtext>cm</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> recorded in Tomsk is reported. In this region 4292 lines are observed belonging to 7 water isotopologues: 536 lines – H<span><math><mrow><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow></mrow><mrow><mn>16</mn></mrow></msup></mrow></math></span>O<!--> <!-->1019 – HD<sup>16</sup>O, 122 – D<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> <span><math><msup><mrow></mrow><mrow><mn>16</mn></mrow></msup></math></span>O, 447 – H<span><math><mrow><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub><msup><mrow></mrow><mrow><mn>17</mn></mrow></msup></mrow></math></span>O<!--> <!-->458 – HD<sup>17</sup>O, 151 – H<span><math><msubsup><mrow></mrow><mrow><mn>2</mn></mrow><mrow><mn>18</mn></mrow></msubsup></math></span>O, 181 – HD<sup>18</sup>O. A new potential energy surface (PES) of HD<sup>16</sup>O is obtained by fitting to empirical energy levels. This PES, with a diagonal Born–Oppenheimer correction (DBOC), is used to compute the HD<sup>17</sup>O spectrum. Pseudo-experimental isotopologue-extrapolation energy levels of HD<sup>17</sup>O are constructed using the method of Polyansky et al (MNRAS 466, 1363 (2017)). Assignment of the measured spectrum is conducted: 68 % of the lines can be assigned using assignments from previously published work. The remaining lines are assigned using the pseudo-experimental energy levels procedure. We compare the calculated pseudo-experimental values of energy levels with both existing 1285 experimental levels of HD<sup>17</sup>O and the 152 newly determined in this work energy levels. The standard deviation of levels with low J (up to J=10) is about 0.007 <span><math><msup><mrow><mtext>cm</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> in both cases. Energy levels from both pseudo-experimental and variationally calculated are also compared with newly measured HD<sup>17</sup>O lines above 10 000 <span><math><msup><mrow><mtext>cm</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111965"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171341","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.2024.111981
Khaled El-Shazly, Heather R. Legg, Jayden Wilkinson, David Kapp, Laura R. McCunn
One commonly observed product of the pyrolysis of many types of biomass is the cyclic oxygenated heterocycle 2-pyrone (2H-Pyran-2-one). Applying matrix-isolation techniques, the thermal decomposition products of 2-pyrone were identified by depositing a diluted mixture of sample and argon through a heated SiC tube onto a cold CsI window, which was then characterized by FT-IR. Experimental spectra collected following pyrolysis at 1400 K indicate the formation of acetylene, vinylacetylene, propargyl, propyne, allyl, carbon dioxide, carbon monoxide, ketene, and furan. Several bands in the vicinity of the antisymmetric CCO stretch of ketene are tentatively assigned to vinylketene and formylvinylketene. Computational analysis using Gaussian 09 at the B3LYP/6-311++G (d,p) level of theory was performed to further confirm product assignments. The results of this study are consistent with published theoretical and computational studies of the pyrolysis of furfural, of which 2-pyrone is a reaction intermediate.
{"title":"Characterization of the pyrolysis products of 2-pyrone via matrix-isolation FTIR","authors":"Khaled El-Shazly, Heather R. Legg, Jayden Wilkinson, David Kapp, Laura R. McCunn","doi":"10.1016/j.jms.2024.111981","DOIUrl":"10.1016/j.jms.2024.111981","url":null,"abstract":"<div><div>One commonly observed product of the pyrolysis of many types of biomass is the cyclic oxygenated heterocycle 2-pyrone (2H-Pyran-2-one). Applying matrix-isolation techniques, the thermal decomposition products of 2-pyrone were identified by depositing a diluted mixture of sample and argon through a heated SiC tube onto a cold CsI window, which was then characterized by FT-IR. Experimental spectra collected following pyrolysis at 1400 K indicate the formation of acetylene, vinylacetylene, propargyl, propyne, allyl, carbon dioxide, carbon monoxide, ketene, and furan. Several bands in the vicinity of the antisymmetric C<img>C<img>O stretch of ketene are tentatively assigned to vinylketene and formylvinylketene. Computational analysis using Gaussian 09 at the B3LYP/6-311++G (d,p) level of theory was performed to further confirm product assignments. The results of this study are consistent with published theoretical and computational studies of the pyrolysis of furfural, of which 2-pyrone is a reaction intermediate.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111981"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171322","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.2024.111982
Manamu Kobayashi , Kaori Kobayashi , Brian J. Esselman , R.Claude Woods , Robert J. McMahon , Satoshi Yamamoto , Hiroyuki Ozeki
The rotational spectrum of dichloromethane (methylene chloride, CH2Cl2) was measured with near-continuous frequency coverage from 29 to 750 GHz with 50 kHz resolution, with additional transitions around 11 GHz with 20 kHz resolution. The rest frequencies of transitions for both the vibrational ground state and first fundamental ν4 are observed, measured, and least-squares fit. Transitions for both of these vibrational states are modeled with partial octic, distorted rotor A- and S-reduced Hamiltonians in the Ir representation with nuclear quadrupole coupling. Computed spectroscopic constants at the B3LYP/6–311+G(2d,p) level are compared to their corresponding experimental values. The partition function of dichloromethane is updated.
{"title":"The rotational spectroscopy of dichloromethane (CH235Cl2) in the ground state and ν4 vibrationally excited state from 11 to 750 GHz","authors":"Manamu Kobayashi , Kaori Kobayashi , Brian J. Esselman , R.Claude Woods , Robert J. McMahon , Satoshi Yamamoto , Hiroyuki Ozeki","doi":"10.1016/j.jms.2024.111982","DOIUrl":"10.1016/j.jms.2024.111982","url":null,"abstract":"<div><div>The rotational spectrum of dichloromethane (methylene chloride, CH<sub>2</sub>Cl<sub>2</sub>) was measured with near-continuous frequency coverage from 29 to 750 GHz with 50 kHz resolution, with additional transitions around 11 GHz with 20 kHz resolution. The rest frequencies of transitions for both the vibrational ground state and first fundamental ν<sub>4</sub> are observed, measured, and least-squares fit. Transitions for both of these vibrational states are modeled with partial octic, distorted rotor A- and S-reduced Hamiltonians in the I<em><sup>r</sup></em> representation with nuclear quadrupole coupling. Computed spectroscopic constants at the B3LYP/6–311+G(2d,p) level are compared to their corresponding experimental values. The partition function of dichloromethane is updated.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111982"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171323","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.2024.111983
Joshua Heuvel-Horwitz , Eisen C. Gross , Trevor J. Sears
We describe a project designed to introduce senior undergraduate chemistry and physics majors to the use of more advanced laser spectroscopic techniques and the interpretation of spectroscopic line shapes. We present a spectrometer design comprising modular components that are controlled using a single Python program with a graphical user interface (GUI). Unlike commercial Fourier transform infrared spectrometers typically used in undergraduate laboratories, this instrument can measure much higher resolution (approximately 0.001 cm−1 compared to 0.5 cm−1) data, with significantly higher (10−4) fractional absorption sensitivity. The modular, opentable design allows for easy viewing of optical components and better understanding of the operation of the instrument. We demonstrate the functionality of the spectrometer by measuring the P(23) rotational-vibrational line of the combination band of acetylene at various pressures to extract a self-pressure broadening coefficient. An undergraduate laboratory assignment could also include estimating the Boltzmann constant from data for low pressure Doppler-broadened lines. An additional Python program with a GUI was built for user friendly least squares fitting of collected data. All Python codes developed are freely available on GitLab.
{"title":"Python control of a high-resolution near-infrared spectrometer for undergraduate use","authors":"Joshua Heuvel-Horwitz , Eisen C. Gross , Trevor J. Sears","doi":"10.1016/j.jms.2024.111983","DOIUrl":"10.1016/j.jms.2024.111983","url":null,"abstract":"<div><div>We describe a project designed to introduce senior undergraduate chemistry and physics majors to the use of more advanced laser spectroscopic techniques and the interpretation of spectroscopic line shapes. We present a spectrometer design comprising modular components that are controlled using a single Python program with a graphical user interface (GUI). Unlike commercial Fourier transform infrared spectrometers typically used in undergraduate laboratories, this instrument can measure much higher resolution (approximately 0.001 cm<sup>−1</sup> compared to 0.5 cm<sup>−1</sup>) data, with significantly higher (10<sup>−4</sup>) fractional absorption sensitivity. The modular, open<span><math><mo>−</mo></math></span>table design allows for easy viewing of optical components and better understanding of the operation of the instrument. We demonstrate the functionality of the spectrometer by measuring the P(23) rotational-vibrational line of the <span><math><mrow><msub><mrow><mi>ν</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>+</mo><msub><mrow><mi>ν</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span> combination band of acetylene at various pressures to extract a self-pressure broadening coefficient. An undergraduate laboratory assignment could also include estimating the Boltzmann constant from data for low pressure Doppler-broadened lines. An additional Python program with a GUI was built for user friendly least squares fitting of collected data. All Python codes developed are freely available on GitLab.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111983"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171325","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.2024.111980
J.H. Westerfield , S.E. Worthington-Kirsch , Kyle N. Crabtree
{"title":"Corrigendum to “westerfit: A new program for spin–torsion–rotation spectra” [J. Mol. Spectrosc. 404 (2024) 111928]","authors":"J.H. Westerfield , S.E. Worthington-Kirsch , Kyle N. Crabtree","doi":"10.1016/j.jms.2024.111980","DOIUrl":"10.1016/j.jms.2024.111980","url":null,"abstract":"","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111980"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171327","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 : 2024-11-01DOI: 10.1016/j.jms.2024.111956
Jonathan R. Dotson, C. Zachary Palmer, Ryan C. Fortenberry
Nitrogen’s introduction into the Earth’s atmosphere may stem from interstellar dust particles delivering some form of nitrogen species at the dawn of the planet’s formation. One contributing source of the present nitrogen may be elusive aluminum nitride molecular clusters that are believed to be included within protoplanetary carbonaceous chondritic meteors. The present work utilizes explicitly correlated coupled cluster theory within theoretical spectroscopic techniques to provide rovibrational spectral data for small, cyclic aluminum nitride cluster conformers in the hopes of aiding in searches for such elusive molecules. The most intense transitions for each cluster are the AlH stretches within the 5.2 range with the most intense transition of 584 km mol−1 exhibited by -AlNH. Many clusters investigated herein also possess large dipole moments such as 4.45 D from NH in its C conformation. The intense vibrational transitions and large dipole moments for the molecules studied in this work should be instrumental for the rotational, vibrational, or rovibrational detection of aluminum nitride clusters that may shed light on the origin of the nitrogen present within the Earth’s atmosphere and may hold keys for observing other planet-forming regions.
氮进入地球大气层可能是由于在地球形成之初星际尘埃粒子提供了某种形式的氮物种。目前氮的一个来源可能是难以捉摸的氮化铝分子簇，据信这些分子簇包含在原行星碳质软玉流星中。本研究利用理论光谱学技术中的显相关耦合团簇理论，提供了小型环状氮化铝团簇构象的振动光谱数据，希望能有助于寻找这类难以捉摸的分子。每个簇最强烈的转变是 5.2-5.6μm 范围内的 Al-H 伸展，c-Al3NH4 的最强烈转变为 584 km mol-1。本文研究的许多团簇还具有较大的偶极矩，例如 C2v 构象中的 c-N4H4 具有 4.45 D 的偶极矩。这项工作中研究的分子的强烈振动转变和大偶极矩应有助于对氮化铝团簇进行旋转、振动或滚振探测，从而揭示地球大气中氮元素的来源，并为观测其他行星形成区域提供关键信息。
{"title":"Spectral features for systematic aluminum replacement in N2H2 and c-N4H4 isomers","authors":"Jonathan R. Dotson, C. Zachary Palmer, Ryan C. Fortenberry","doi":"10.1016/j.jms.2024.111956","DOIUrl":"10.1016/j.jms.2024.111956","url":null,"abstract":"<div><div>Nitrogen’s introduction into the Earth’s atmosphere may stem from interstellar dust particles delivering some form of nitrogen species at the dawn of the planet’s formation. One contributing source of the present nitrogen may be elusive aluminum nitride molecular clusters that are believed to be included within protoplanetary carbonaceous chondritic meteors. The present work utilizes explicitly correlated coupled cluster theory within theoretical spectroscopic techniques to provide rovibrational spectral data for small, cyclic aluminum nitride cluster conformers in the hopes of aiding in searches for such elusive molecules. The most intense transitions for each cluster are the Al<span><math><mo>−</mo></math></span>H stretches within the 5.2<span><math><mrow><mo>−</mo><mn>5</mn><mo>.</mo><mn>6</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> range with the most intense transition of 584 km mol<sup>−1</sup> exhibited by <span><math><mi>c</mi></math></span>-Al<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>NH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>. Many clusters investigated herein also possess large dipole moments such as 4.45 D from <span><math><mrow><mi>c</mi><mo>−</mo></mrow></math></span>N<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>H<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> in its C<span><math><msub><mrow></mrow><mrow><mn>2</mn><mi>v</mi></mrow></msub></math></span> conformation. The intense vibrational transitions and large dipole moments for the molecules studied in this work should be instrumental for the rotational, vibrational, or rovibrational detection of aluminum nitride clusters that may shed light on the origin of the nitrogen present within the Earth’s atmosphere and may hold keys for observing other planet-forming regions.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"406 ","pages":"Article 111956"},"PeriodicalIF":1.4,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699147","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 : 2024-10-16DOI: 10.1016/j.jms.2024.111955
D.M. Plastinina , A.S. Lipskaya , E.N. Chesnokov
The frequencies of C2HD hot bands ro-vibrational lines of the first overtone of C-H stretching were measured using tunable diode lasers. To expand the measuring range to the region of the large rotational numbers, a heated gas cell was used. Measurements were made in the range R1–R36 and P2–P14 for the transition (2,0,0,1,0) ← (0,0,0,1,0), and in the range R1–R18 for the transition (2,0,0,0,1) ← (0,0,0,0,1). The rotational parameters of the upper and lower states for the band (2,0,0,1,0) ← (0,0,0,1,0) were determined. The doublet structure of ro-vibrational lines was studied. For the transition (2,0,0,1,0) ← (0,0,0,1,0), a sharp increase in the splitting value was detected at J > 25.
{"title":"High resolution laser diode spectroscopy of the hot bands of C2HD in the first overtone region of C-H stretching","authors":"D.M. Plastinina , A.S. Lipskaya , E.N. Chesnokov","doi":"10.1016/j.jms.2024.111955","DOIUrl":"10.1016/j.jms.2024.111955","url":null,"abstract":"<div><div>The frequencies of C<sub>2</sub>HD hot bands ro-vibrational lines of the first overtone of C-H stretching were measured using tunable diode lasers. To expand the measuring range to the region of the large rotational numbers, a heated gas cell was used. Measurements were made in the range R1–R36 and P2–P14 for the transition (2,0,0,1,0) ← (0,0,0,1,0), and in the range R1–R18 for the transition (2,0,0,0,1) ← (0,0,0,0,1). The rotational parameters of the upper and lower states for the band (2,0,0,1,0) ← (0,0,0,1,0) were determined. The doublet structure of ro-vibrational lines was studied. For the transition (2,0,0,1,0) ← (0,0,0,1,0), a sharp increase in the splitting value was detected at J > 25.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"406 ","pages":"Article 111955"},"PeriodicalIF":1.4,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535262","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 : 2024-10-11DOI: 10.1016/j.jms.2024.111952
Joshua E. Isert , Josie R. Glenn , S.A. Cooke , G.S. Grubbs II
Pure rotational transitions for HfS and ThS have been measured in highly excited vibrational states. For HfS, rotational transitions have been recorded in up to the 19th excited vibrational state, whereas for ThS measurements extend up to the 17th excited vibrational state. Pure rotational transitions have also been recorded for Th34S for the first time. In both cases isotopically invariant analyses have been performed and very accurate equilibrium bond lengths have been determined.
{"title":"Pure rotational spectroscopic measurements on the electronic ground states of Hafnium monosulfide and Thorium monosulfide in highly excited vibrational states","authors":"Joshua E. Isert , Josie R. Glenn , S.A. Cooke , G.S. Grubbs II","doi":"10.1016/j.jms.2024.111952","DOIUrl":"10.1016/j.jms.2024.111952","url":null,"abstract":"<div><div>Pure rotational transitions for HfS and ThS have been measured in highly excited vibrational states. For HfS, rotational transitions have been recorded in up to the 19th excited vibrational state, whereas for ThS measurements extend up to the 17th excited vibrational state. Pure rotational transitions have also been recorded for Th<sup>34</sup>S for the first time. In both cases isotopically invariant analyses have been performed and very accurate equilibrium bond lengths have been determined.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"406 ","pages":"Article 111952"},"PeriodicalIF":1.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535261","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}
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