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Jiang J, Saladrigas CA, Erickson TJ, Keenan CL, Field RW. Probing the predissociated levels of the S 1 state of acetylene via H-atom fluorescence and photofragment fluorescence action spectroscopy. J Chem Phys 2018; 149:174309. [PMID: 30408969 DOI: 10.1063/1.5045046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report two new experimental schemes to obtain rotationally resolved high-resolution spectra of predissociated S1 acetylene levels in the 47 000-47 300 cm-1 energy region (∼1200 cm-1 above the predissociation threshold). The two new detection schemes are compared to several other detection schemes (employed at similar laser power, molecular beam temperature, and number of signal averages) that have been used in our laboratory to study predissociated S1 acetylene levels, both in terms of the signal-to-noise ratio (S/N) of the resultant spectra and experimental simplicity. In the first method, H-atoms from the predissociated S1 acetylene levels are probed by two-photon laser-induced fluorescence (LIF). The H-atoms are pumped to the 3d level by the two-photon resonance transition at 205.14 nm. The resulting 3d-2p fluorescence (654.5 nm) is collected by a photomultiplier. The S/N of the H-atom fluorescence action spectrum is consistently better by ∼3× than that of the more widely used H-atom resonance-enhanced multiphoton ionization (REMPI) detection. Laser alignment is also considerably easier in H-atom fluorescence detection than H-atom REMPI detection due to the larger number-density of molecules that can be used in fluorescence vs. REMPI detection schemes. In the second method, fluorescence from electronically excited C2 and C2H photofragments of S1 acetylene is detected. In contrast to the H-atom detection schemes, the detected C2 and C2H photofragments are produced by the same UV laser as is used for the à - X ̃ acetylene excitation. As a result, laser alignment is greatly simplified for the photofragment fluorescence detection scheme, compared to both H-atom detection schemes. Using the photofragment fluorescence detection method, we are able to obtain action spectra of predissociated S1 acetylene levels with S/N ∼2× better than the HCCH REMPI detection and ∼10× better than H-atom and HCCH LIF detection schemes.
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Affiliation(s)
- Jun Jiang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Catherine A Saladrigas
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Trevor J Erickson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Clare L Keenan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Roenitz KM, Hays BM, Powers CR, McCabe MN, Smith H, Widicus Weaver SL, Shipman ST. AC Stark Effect Observed in a Microwave-Millimeter/Submillimeter Wave Double-Resonance Experiment. J Phys Chem A 2018; 122:6321-6327. [PMID: 29993251 DOI: 10.1021/acs.jpca.8b02116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microwave-millimeter/submillimeter wave double-resonance spectroscopy has been developed with the use of technology typically employed in chirped pulse Fourier transform microwave spectroscopy and fast-sweep direct absorption (sub)millimeter-wave spectroscopy. This technique offers the high sensitivity provided by millimeter/submillimeter fast-sweep techniques with the rapid data acquisition offered by chirped pulse Fourier transform microwave spectrometers. Rather than detecting the movement of population as is observed in a traditional double-resonance experiment, instead we detected the splitting of spectral lines arising from the AC Stark effect. This new technique will prove invaluable when assigning complicated rotational spectra of complex molecules. The experimental design is presented along with the results from the double-resonance spectra of methanol as a proof-of-concept for this technique.
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Affiliation(s)
- Kevin M Roenitz
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Brian M Hays
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Carson R Powers
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Morgan N McCabe
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Houston Smith
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | | | - Steven T Shipman
- Division of Natural Sciences , New College of Florida , Sarasota , Florida 34243 , United States
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Laruelle F, Boyé-Péronne S, Gauyacq D, Liévin J. Revisiting Mulliken’s Concepts about Rydberg States and Rydberg−Valence Interactions from Large-Scale Ab Initio Calculations on the Acetylene Molecule. J Phys Chem A 2009; 113:13210-20. [DOI: 10.1021/jp903948k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fabrice Laruelle
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Séverine Boyé-Péronne
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Dolores Gauyacq
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Jacques Liévin
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
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Robert S, Amyay B, Fayt A, Di Lonardo G, Fusina L, Tamassia F, Herman M. Vibration−Rotation Energy Pattern in Acetylene: 13CH12CH up to 10 120 cm−1. J Phys Chem A 2009; 113:13251-9. [DOI: 10.1021/jp904000q] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S. Robert
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - B. Amyay
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - A. Fayt
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - G. Di Lonardo
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - L. Fusina
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - F. Tamassia
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
| | - M. Herman
- Service de Chimie Quantique et Photophysique CP160/09, Faculté des Sciences, Université Libre de Bruxelles, Av. Roosevelt, 50, B-1050 Bruxelles, Belgium, Laboratoire de Spectroscopie Moléculaire, Université Catholique de Louvain, Chemin du Cyclotron, 2, B-1348 Louvain-La-Neuve, Belgium, and Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento, 4, I-40136 Bologna, Italy
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