Journal of Molecular Spectroscopy最新文献_第5页

The microwave spectrum of the low energy conformers of 1-ethylsilacyclopentane 1-ethylsilacyclopentane 低能构象的微波光谱

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2024-01-01 DOI: 10.1016/j.jms.2023.111872

Josie R. Glenn , J.E. Isert , Jacob D. Bethke , Gamil A. Guirgis , G.S. Grubbs II

引用次数: 0

The microwave spectrum of the low energy conformers of 1-ethylsilacyclopentane 1-ethylsilacyclopentane 低能构象的微波光谱

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-12-20 DOI: 10.1016/j.jms.2023.111872

Josie R. Glenn, J.E. Isert, Jacob D. Bethke, Gamil A. Guirgis, G.S. Grubbs II

引用次数: 0

Analysis of the calculated and observed X-X ro-vibrational transition intensities in molecular hydrogen 氢分子中X-X反振动跃迁强度的计算与观测分析

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-12-05 DOI: 10.1016/j.jms.2023.111863

V.G. Ushakov , S.A. Balashev , E.S. Medvedev

{"title":"Analysis of the calculated and observed X-X ro-vibrational transition intensities in molecular hydrogen","authors":"V.G. Ushakov , S.A. Balashev , E.S. Medvedev","doi":"10.1016/j.jms.2023.111863","DOIUrl":"10.1016/j.jms.2023.111863","url":null,"abstract":"<div>The potential-energy and quadrupole-moment functions of the H<math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math> ground electronic state are well known in literature (Komasa et al., 2019; Wolniewicz et al., 1998), and the line list of the vibrational–rotational transitions was calculated (Roueff et al., 2019). In this paper, we analyze the calculated intensities in order to learn how the intensities will change when analytic quadrupole-moment functions fitted to the ab initio and experimental data are used instead of spline-interpolated functions. We found that the use of splines does not deteriorate the intensities and does not lead to nonphysical saturation, as in heavier molecules, owing to the high precision of the ab initio data and the high density of the grid. The accuracy of the calculated intensities is estimated up to high overtones. Extraction of new spectroscopic information from the observational data that supplements the laboratory measurements is performed. The laboratory and observational data do not help increase the quality of the analytic functions. Numerous anomalies resulting from the destructive interference are identified in the calculated line lists, some of them being situated within the recently observed spectral regions, 1.5–<math><mrow><mn>2</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math>. The intensities of these anomalies can be sensitive to the form of the molecular functions as well as to the proton-to-electron mass ratio. In this connection, the similar Le Roy anomalies (Brown and LeRoy, 1973; Le Roy and Vrscay, 1975) also arising due to the destructive interference in the Lyman and Werner systems are discussed.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"399 ","pages":"Article 111863"},"PeriodicalIF":1.4,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138529739","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}

引用次数: 0

A Rare Case of Retropharyngeal Abscess in a 3 Month Old Male Infant: Case Report and Review of Literature. 罕见的3月龄男婴咽后脓肿1例报告及文献复习。

IF 0.6 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-12-01 Epub Date: 2023-07-11 DOI: 10.1007/s12070-023-04043-2

Lohith Rajanna, Sheetal Raina, Himanshu Chhagan Bayad, Shailendra Tripathi, Omvir Singh Chahar, Ombir Singh

{"title":"A Rare Case of Retropharyngeal Abscess in a 3 Month Old Male Infant: Case Report and Review of Literature.","authors":"Lohith Rajanna, Sheetal Raina, Himanshu Chhagan Bayad, Shailendra Tripathi, Omvir Singh Chahar, Ombir Singh","doi":"10.1007/s12070-023-04043-2","DOIUrl":"10.1007/s12070-023-04043-2","url":null,"abstract":"Retropharyngeal abscess (RPA) is a rare, potentially fatal condition found more frequently in young children usually who were having a history of Upper respiratory infection. RPA is an acute suppurative infection of the retropharyngeal space. In view of scarce literature availability and atypical presentation in infants, it poses a definitive diagnostic dilemma to the clinicians. Here, we are reporting a three-month-old male infant presented with feeding difficulty, obstructive sleep apnea and intermittent inspiratory stridor. Child was managed in a pediatric ICU with a multidisciplinary approach which involved pediatrician, otorhinolaryngologist pediatric anesthesiologist, microbiologist, and radiologist. With the recent advances, early radio imaging have a vital role in diagnosing the condition and also helps in planning of surgery. Prompt diagnosis and surgical management with appropriate antimicrobial therapy for this condition is imperative to prevent complications such as airway obstruction and mediastinitis. Timely surgical intervention, preferably intraoral transpharyngeal approach, to drain the abscess is recommended.","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"137 1","pages":"4066-4070"},"PeriodicalIF":0.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10646015/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74899031","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}

引用次数: 0

Microwave measurements and structure calculations for a glyoxylic acid – Water complex 乙醛酸-水复合物的微波测量和结构计算

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-29 DOI: 10.1016/j.jms.2023.111862

Adam M. Daly, Rhett P. Hill, Myla G. Gonzalez, Stephen G. Kukolich

引用次数: 0

Potential and kinetic interaction of two internal tops in molecules belonging to C2v(M) molecular symmetry group C2v(M)分子对称基分子中两个内顶的势和动力学相互作用

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-22 DOI: 10.1016/j.jms.2023.111860

George A. Pitsevich , Alex E. Malevich , Uladzimir U. Sapeshka

{"title":"Potential and kinetic interaction of two internal tops in molecules belonging to C2v(M) molecular symmetry group","authors":"George A. Pitsevich , Alex E. Malevich , Uladzimir U. Sapeshka","doi":"10.1016/j.jms.2023.111860","DOIUrl":"https://doi.org/10.1016/j.jms.2023.111860","url":null,"abstract":"<div>Fourier analysis of the kinetic and potential interactions of non-coaxial internal tops in the molecules C6H4(OH)2, HO(CH2)OH, HOOOH, HOSOH, HSSSH, and HSOSH was carried out. It was found that for the all six molecules, in which both tops are characterized by a period 2 <math><mi>π</mi></math>, the harmonics with a period of <math><mi>π</mi></math> are dominate, with its contribution to the Fourier representation of potential surfaces increasing in the sequence mentioned above. Contributions of internal tops interactions to the kinetic and potential energies were determined for analyzed molecules. The influence of potential and kinetic interactions of internal tops on 1) the features of tunneling splitting of the ground and excited torsional states of molecules, 2) the landscape of 2D potential energy surfaces, 3) frequencies of fundamental torsional vibrations of hydroxyl and thiol groups, 4) the ratio of trans - and cis - conformer energies is also analyzed.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"399 ","pages":"Article 111860"},"PeriodicalIF":1.4,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138447972","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}

引用次数: 0

The C2H4O isomers in the oxidation of ethylene 乙烯氧化过程中的C2H4O异构体

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-01 DOI: 10.1016/j.jms.2023.111847

Nathan A. Seifert , Branko Ruscic , Raghu Sivaramakrishnan , Kirill Prozument

{"title":"The C2H4O isomers in the oxidation of ethylene","authors":"Nathan A. Seifert , Branko Ruscic , Raghu Sivaramakrishnan , Kirill Prozument","doi":"10.1016/j.jms.2023.111847","DOIUrl":"https://doi.org/10.1016/j.jms.2023.111847","url":null,"abstract":"<div>A combined rotational spectroscopy, thermochemistry, and kinetic modeling study explores the mechanism of acetaldehyde (ethanal), vinyl alcohol (ethenol), and ethylene oxide (oxirane) formation in the oxidation of ethylene (ethene). Multiplexed quantitative detection of oxidation intermediates and products exiting a SiO2/SiC microreactor at 1700 K is demonstrated with the BrightSpec W-band chirped-pulse Fourier transform millimeter-wave spectrometer. The broadband rotational spectrum contains transitions of formaldehyde (CH2O), methoxy (CH3O), methanol (CH3OH), ketene (CH2CO), acetaldehyde (CH3CHO), syn-vinyl alcohol (syn-CH2CHOH), anti-vinyl alcohol (anti-CH2CHOH), oxirane (c-CH2OCH2), propyne (CH3CCH), and syn-propanal (syn-CH3CH2CHO). We focus on the three C2H4O species and deduce their concentration ratio [CH3CHO]:[CH2CHOH]:[c-CH2OCH2] = 1:0.7(2):0.06(2) by comparing the observed line intensities to those simulated with the PGOPHER software. Detailed thermochemistry of the C2H4O isomers and conformers is provided by Active Thermochemical Tables. The observed excess concentrations of vinyl alcohol and oxirane relative to the more stable acetaldehyde compared to the equilibrium ratio at 1700 K (1:0.087:0.000024), point to direct chemical pathways to these higher energy isomers. The mechanism for the formation of the three C2H4O isomers is analyzed using a 0-D homogenous reactor kinetics simulation for ethylene oxidation. The ratios of the C2H4O isomers concentrations predicted by the kinetic model are compared to the experimental values.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"398 ","pages":"Article 111847"},"PeriodicalIF":1.4,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92100879","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}

引用次数: 0

Manifestation of binary collisions in the Raman-allowed bending vibrational band of the SF6 molecule SF6分子拉曼允许弯曲振动带中二元碰撞的表现

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-01 DOI: 10.1016/j.jms.2023.111857

Florent Rachet, Michael Chrysos

{"title":"Manifestation of binary collisions in the Raman-allowed bending vibrational band of the SF6 molecule","authors":"Florent Rachet, Michael Chrysos","doi":"10.1016/j.jms.2023.111857","DOIUrl":"https://doi.org/10.1016/j.jms.2023.111857","url":null,"abstract":"<div>A careful, principally experimental Raman study which puts the focus on the <math><msub><mrow><mi>ν</mi></mrow><mrow><mn>5</mn></mrow></msub></math> bending vibrational band by gaseous room-temperature sulfur hexafluoride is reported. In essence, our results boil down in the following two findings. Firstly, the anisotropic Raman-allowed spectrum by that band, which for the first time was isolated from the recordings and calibrated on an absolute scale. Secondly, an absolute-calibrated binary collision-induced component, which was also for the first time extracted from the crude measurements in the wavenumber range 475–570 cm−1. Both spectra are depolarized and lead to parameters in agreement with the existing literature. The reported findings bring us one step closer to understanding how vibration mechanisms work in S<math><msub><mrow><mi>F</mi></mrow><mrow><mn>6</mn></mrow></msub></math> and show among other things that, at the <math><msub><mrow><mi>ν</mi></mrow><mrow><mn>5</mn></mrow></msub></math> frequency, collisions between molecules enhance light scattering by 0.8% at 1 atm and by 13% at 15 atm of sulfur hexafluoride gas pressure.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"398 ","pages":"Article 111857"},"PeriodicalIF":1.4,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92046565","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}

引用次数: 0

The 130 – 750 GHz rotational spectrum of 2-cyanopyridine – Analysis of the ground vibrational state and the Coriolis-coupled dyad of its lowest-energy fundamental states 2-氰吡啶的130 - 750ghz旋转频谱。基态振动和其最低能量基本态的科里奥利耦合二极体分析

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-01 DOI: 10.1016/j.jms.2023.111842

P. Matisha Dorman, Brian J. Esselman, Maria A. Zdanovskaia, R. Claude Woods, Robert J. McMahon

{"title":"The 130 – 750 GHz rotational spectrum of 2-cyanopyridine – Analysis of the ground vibrational state and the Coriolis-coupled dyad of its lowest-energy fundamental states","authors":"P. Matisha Dorman, Brian J. Esselman, Maria A. Zdanovskaia, R. Claude Woods, Robert J. McMahon","doi":"10.1016/j.jms.2023.111842","DOIUrl":"https://doi.org/10.1016/j.jms.2023.111842","url":null,"abstract":"<div>The millimeter-wave rotational spectrum of 2-cyanopyridine was collected from 130 to 750 GHz, and the ground and two lowest-energy excited vibrational states were analyzed. In total, over 20,000 rotational transitions were least-squares fit for the three vibrational states to partial-octic, distorted-rotor Hamiltonians with low error (σfit < 50 kHz). For the ground state, the many thousands of newly measured rotational transitions enabled substantial refinement of the rotational constants and determination of the centrifugal distortion constants. The rotational spectrum was collected at room temperature, permitting the observation of the two lowest-energy fundamental modes, ν30 (A″, 154 cm−1) and ν21 (A′, 175 cm−1), and determination of their spectroscopic constants. The two excited vibrational states are Coriolis coupled and require a two-state Hamiltonian. Eight Coriolis-coupling parameters (<math><mrow><msub><mi>G</mi><mi>a</mi></msub><mo>,</mo><msubsup><mi>G</mi><mrow><mi>a</mi></mrow><mi>J</mi></msubsup><mo>,</mo><msubsup><mi>G</mi><mrow><mi>a</mi></mrow><mi>K</mi></msubsup><mo>,</mo><msubsup><mi>G</mi><mrow><mi>a</mi></mrow><mrow><mi>JJ</mi></mrow></msubsup><mo>,</mo><msub><mi>F</mi><mrow><mi>bc</mi></mrow></msub><mo>,</mo><msubsup><mi>F</mi><mrow><mi>bc</mi></mrow><mi>J</mi></msubsup><mo>,</mo><msub><mi>G</mi><mi>b</mi></msub><mo>,</mo></mrow></math>and <math><mrow><msubsup><mi>G</mi><mrow><mi>b</mi></mrow><mi>J</mi></msubsup></mrow></math>) have been determined, as well as a precise energy difference of 26.524 312 6 (40) cm−1 between the vibrational states. A comparison of the ground-state spectroscopic constants, as well as the Coriolis coupling-related parameters of analogous dyads is presented for multiple cyanoarenes.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"398 ","pages":"Article 111842"},"PeriodicalIF":1.4,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91963766","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}

引用次数: 0

Taming semi-empirical methods for PAHs and vibrational spectra 多环芳烃的半经验方法与振动谱

IF 1.4 4区物理与天体物理

Journal of Molecular Spectroscopy Pub Date : 2023-11-01 DOI: 10.1016/j.jms.2023.111846

Brent R. Westbrook, Ryan C. Fortenberry

{"title":"Taming semi-empirical methods for PAHs and vibrational spectra","authors":"Brent R. Westbrook, Ryan C. Fortenberry","doi":"10.1016/j.jms.2023.111846","DOIUrl":"https://doi.org/10.1016/j.jms.2023.111846","url":null,"abstract":"<div>Semi-empirical methods offer a cost-effective means of computing explicit, anharmonic vibrational frequencies for large molecules, such as polycyclic aromatic hydrocarbons (PAHs), but their default parameters produce insufficiently accurate results for comparison to experiment, especially in the hydride stretching region where the NIRSpec instrument on JWST is most effective. This work delivers several reparameterized variants of the PM6 semi-empirical method trained to reproduce the experimental vibrational frequencies of 5 small hydrocarbon molecules. When benchmarked on the experimental frequencies of benzene and naphthalene, these reparameterized methods match the empirical values to within 38.7 cm<math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> on average. Combining these values with the default PM6 frequencies below 3000 cm<math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> brings the average deviation below 22 cm<math><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> for naphthalene, comparing favorably with the existing state of the art in B3LYP/4-31G, for a two order of magnitude decrease in the computational cost. As such, the present work offers a promising means of extending the computation of explicit, anharmonic vibrational frequencies to PAHs larger than those that can be examined anharmonically via B3LYP. Such large and accurate data sets are necessary to disentangle the unidentified spectral features observed around myriad astronomical bodies and the influx of observational data from JWST.</div>","PeriodicalId":16367,"journal":{"name":"Journal of Molecular Spectroscopy","volume":"398 ","pages":"Article 111846"},"PeriodicalIF":1.4,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91963767","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}

引用次数: 0