Khaled El-Shazly, Heather R. Legg, Jayden Wilkinson, David Kapp, Laura R. McCunn
{"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}
Manamu Kobayashi , Kaori Kobayashi , Brian J. Esselman , R.Claude Woods , Robert J. McMahon , Satoshi Yamamoto , Hiroyuki Ozeki
{"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}
Joshua Heuvel-Horwitz , Eisen C. Gross , Trevor J. Sears
{"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}
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}
Jonathan R. Dotson, C. Zachary Palmer, Ryan C. Fortenberry
{"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}
{"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}
Joshua E. Isert , Josie R. Glenn , S.A. Cooke , G.S. Grubbs II
{"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}
Thomas Howard, Shannon E. Ganley, Sanjana Maheshwari, Leah G. Dodson
{"title":"Buffer-gas cooling of hydrogen cyanide quantified by cavity-ringdown spectroscopy","authors":"Thomas Howard, Shannon E. Ganley, Sanjana Maheshwari, Leah G. Dodson","doi":"10.1016/j.jms.2024.111953","DOIUrl":"10.1016/j.jms.2024.111953","url":null,"abstract":"<div><div>We describe an instrument that uses continuous-wave (CW) cavity-ringdown spectroscopy to measure the translational and rotational temperature of buffer-gas cooled molecules and demonstrate its use on hydrogen cyanide. This instrument can access the near-infrared region around 1.5 μm—a rich spectral region that features the rotationally resolved first overtone of the C-H stretch for many astrophysically relevant molecules. Molecules are probed directly inside the buffer-gas cell, further enabling quantitative measurements of the effectiveness of this cooling technique.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"406 ","pages":"Article 111953"},"PeriodicalIF":1.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535260","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":"Isotopic species, vibrational states and nuclear quadrupole splitting in CH2Cl2 from rotational spectroscopy at 8–18 GHz","authors":"Zbigniew Kisiel","doi":"10.1016/j.jms.2024.111954","DOIUrl":"10.1016/j.jms.2024.111954","url":null,"abstract":"<div><div>The present work fills several significant gaps in the study of the rotational spectrum of the methylene chloride molecule. Two Fourier transform microwave spectrometers were used, providing complementary coverage of the 8–18 GHz region, at room temperature and in supersonic expansion. Hyperfine resolved measurements were made and fitted for ground states of the CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>35</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>35</sup>Cl<sup>37</sup>Cl, CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>37</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and <sup>13</sup>CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>35</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> isotopic species, as well as for nine different excited vibrational states. Transitions in the <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>2</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>3</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span>, <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>9</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> states in CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>35</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, and transitions in excited states of the <span><math><msub><mrow><mi>ν</mi></mrow><mrow><mn>4</mn></mrow></msub></math></span> mode in <sup>35</sup>Cl<sup>37</sup>Cl and <sup>37</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> isotopic species have been assigned for the first time. Vibrational and isotopic dependence of nuclear quadrupole coupling constants was identified. The <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> and <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>9</mn></mrow></msub><mo>=</mo><mn>1</mn></mrow></math></span> states in CH<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span><sup>35</sup>Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> were found to be significantly coupled by <span><math><mi>c</mi></math></span>-axis Coriolis interaction, while transitions in <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>2</mn></mrow></math></span> and <span><math><mrow><msub><mrow><mi>v</mi></mrow><mrow><mn>4</mn></mrow></msub><mo>=</mo><mn>3</mn></mrow></math></span> states exhibited hyperfine mediated p","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"406 ","pages":"Article 111954"},"PeriodicalIF":1.4,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535263","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}
Nan Fang , Chuan-Yu Zhang , Ming-Jie Wan , Xiao-Peng Huang
{"title":"Theoretical study on the spectrum properties of tellurium iodide cation","authors":"Nan Fang , Chuan-Yu Zhang , Ming-Jie Wan , Xiao-Peng Huang","doi":"10.1016/j.jms.2024.111951","DOIUrl":"10.1016/j.jms.2024.111951","url":null,"abstract":"<div><div>The molecular potential energy function plays an important role in many fields. In this paper, the icMRCI + Q method was utilized to compute the potential energy and dipole moments for 22 Λ-S states and 51 Ω states of the TeI<sup>+</sup> system. Two basis sets (AVQZ-PP and AWCVQZ-PP) were employed to compute the TeI<sup>+</sup> system, with the results indicating that the AVQZ-PP basis set yielded more accurate results. Therefore, all calculations in this paper are based on this basis set. Furthermore, to ensure the accuracy of the results, a comparison was conducted on the spectral parameters of the ground state and two excited states of the molecular ion within the same main group. Given the significant impact of spin–orbit coupling, as indicated by the calculated SO matrix elements, our discussion will predominantly center on the avoidance of crossovers in the Ω states. Finally, the Franck-Condon factors, Einstein coefficients and radiative lifetime between these two states were calculated from the data of the transition between the <span><math><mrow><msup><mi>X</mi><mn>3</mn></msup><msubsup><mi>Σ</mi><mrow><msup><mn>0</mn><mo>+</mo></msup></mrow><mo>-</mo></msubsup><mo>↔</mo><msup><mn>1</mn><mn>1</mn></msup><msubsup><mi>Σ</mi><mrow><msup><mn>0</mn><mo>+</mo></msup></mrow><mo>+</mo></msubsup></mrow></math></span> of the TeI<sup>+</sup> molecule.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"405 ","pages":"Article 111951"},"PeriodicalIF":1.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142426406","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}