Journal of Molecular Spectroscopy最新文献

{"title":"Revisiting the microwave spectrum and molecular structure of 1-fluoronaphthalene","authors":"Surabhi Gupta ,&nbsp;Charlotte N. Cummings ,&nbsp;Nicholas R. Walker ,&nbsp;Elangannan Arunan","doi":"10.1016/j.jms.2024.111968","DOIUrl":"10.1016/j.jms.2024.111968","url":null,"abstract":"<div><div>Rotational spectra of 1-fluoronaphthalene isotopologues have been recorded using a chirped-pulse Fourier transform microwave spectrometer in the 2.0–8.0 GHz frequency range using neon as a carrier gas. Ten ¹³C isotopomers (each containing only a single ¹²C/¹³C substitution) of 1-fluoronaphthalene have been assigned in natural abundance for the first time. The rotational constants <em>A</em>₀, <em>B</em>₀, and <em>C</em>₀ and inertial defects are determined from experimentally measured transition frequencies. For all isotopologues, the measured values of inertial defects were observed to fall within the range from −0.142 to −0.145 u Ų. The negative inertial defects are attributed to the low frequency, out-of-plane bending mode of the 1-fluoronaphthalene ring, which is evidently of similar frequency in each isotopologue. The anharmonic frequency of this mode has been calculated to be 142.8 cm⁻¹ at the B3LYP-D3/cc-pVTZ level of theory, compared to 94 cm⁻¹ predicted from the inertial defect based on an empirical relation proposed by Oka. Recent, unpublished, THz Raman spectrum reveals a peak at 75 cm⁻¹, which is closer to the empirical prediction.</div></div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"407 ","pages":"Article 111968"},"PeriodicalIF":1.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171328","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":"Three-states model for calculating the X-X rovibrational transition intensities in hydroxyl radical","authors":"V.G. Ushakov ,&nbsp;A. Yu. Ermilov ,&nbsp;E.S. Medvedev","doi":"10.1016/j.jms.2024.111977","DOIUrl":"10.1016/j.jms.2024.111977","url":null,"abstract":"&lt;div&gt;&lt;div&gt;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 &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mi&gt;Π&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and first excited &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;Σ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; electronic states was treated by the perturbation theory. In this paper, we performed &lt;em&gt;ab initio&lt;/em&gt; calculations of all necessary molecular functions at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;-8.0 bohr, and then we construct fully analytic model functions entering the Hamiltonian. The model functions were fitted to both the &lt;em&gt;ab initio&lt;/em&gt; 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 &lt;span&gt;&lt;math&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; state plus the &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; state was solved to calculate the energy levels and the line intensities. The new set of the Einstein &lt;em&gt;A&lt;/em&gt; 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 &lt;span&gt;&lt;math&gt;&lt;mi&gt;Λ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; doublets for large &lt;span&gt;&lt;math&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; as observed by Noll et al. The &lt;span&gt;&lt;math&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-&lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; coupling fully modifies the Q-line intensities at high &lt;span&gt;&lt;math&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; by removing the well-known &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;J&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; dependence. A new line list is constructed where the transition frequencies are from Brooke et al. and the Einstein &lt;span&gt;&lt;math&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; 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 &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;Σ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;Σ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/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}

{"title":"Free-jet absorption millimeter-wave spectrum of 2’-aminoacetophenone","authors":"Salvatore Boi ,&nbsp;Sonia Melandri ,&nbsp;Luca Evangelisti ,&nbsp;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⁻¹ 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⁻¹. This difference increases to 150 cm⁻¹ 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}

{"title":"Study of HD17O spectrum. Theory and experiment","authors":"Leonid N. Sinitsa ,&nbsp;Nikolai F. Zobov ,&nbsp;Mikhail A. Rogov ,&nbsp;Jonathan Tennyson ,&nbsp;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 HD¹⁷O 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 – HD¹⁶O, 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 – HD¹⁷O, 151 – H<span><math><msubsup><mrow></mrow><mrow><mn>2</mn></mrow><mrow><mn>18</mn></mrow></msubsup></math></span>O, 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 <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 HD¹⁷O 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}

{"title":"Characterization of the pyrolysis products of 2-pyrone via matrix-isolation FTIR","authors":"Khaled El-Shazly,&nbsp;Heather R. Legg,&nbsp;Jayden Wilkinson,&nbsp;David Kapp,&nbsp;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}

{"title":"The rotational spectroscopy of dichloromethane (CH235Cl2) in the ground state and ν4 vibrationally excited state from 11 to 750 GHz","authors":"Manamu Kobayashi ,&nbsp;Kaori Kobayashi ,&nbsp;Brian J. Esselman ,&nbsp;R.Claude Woods ,&nbsp;Robert J. McMahon ,&nbsp;Satoshi Yamamoto ,&nbsp;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, 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 I<em>^r</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}

{"title":"Python control of a high-resolution near-infrared spectrometer for undergraduate use","authors":"Joshua Heuvel-Horwitz ,&nbsp;Eisen C. Gross ,&nbsp;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⁻¹ compared to 0.5 cm⁻¹) data, with significantly higher (10⁻⁴) 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}

{"title":"Corrigendum to “westerfit: A new program for spin–torsion–rotation spectra” [J. Mol. Spectrosc. 404 (2024) 111928]","authors":"J.H. Westerfield ,&nbsp;S.E. Worthington-Kirsch ,&nbsp;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}

{"title":"Spectral features for systematic aluminum replacement in N2H2 and c-N4H4 isomers","authors":"Jonathan R. Dotson,&nbsp;C. Zachary Palmer,&nbsp;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⁻¹ 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 ,&nbsp;A.S. Lipskaya ,&nbsp;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 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 &gt; 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}