Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow
A new chirped-pulse/uniform flow (CPUF) spectrometer has been developed and used to determine product branching in a multichannel reaction. With this technique, bimolecular reactions can be initiated in a cold, thermalized, high-density molecular flow and a broadband microwave spectrum acquired for...
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| Format: | Article |
| Language: | en_US |
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American Chemical Society (ACS)
2016
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| Online Access: | http://hdl.handle.net/1721.1/105098 https://orcid.org/0000-0002-7609-4205 |
| _version_ | 1826211152297721856 |
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| author | Abeysekera, Chamara Joalland, Baptiste Ariyasingha, Nuwandi Zack, Lindsay N. Sims, Ian R. Suits, Arthur G. Field, Robert W |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Abeysekera, Chamara Joalland, Baptiste Ariyasingha, Nuwandi Zack, Lindsay N. Sims, Ian R. Suits, Arthur G. Field, Robert W |
| author_sort | Abeysekera, Chamara |
| collection | MIT |
| description | A new chirped-pulse/uniform flow (CPUF) spectrometer has been developed and used to determine product branching in a multichannel reaction. With this technique, bimolecular reactions can be initiated in a cold, thermalized, high-density molecular flow and a broadband microwave spectrum acquired for all products with rotational transitions within a chosen frequency window. In this work, the CN + CH3CCH reaction was found to yield HCN via a direct H-abstraction reaction, whereas indirect addition/elimination pathways to HCCCN, CH3CCCN, and CH2CCHCN were also probed. From these observations, quantitative branching ratios were established for all products as 12(5)%, 66(4)%, 22(6)%, and 0(8)% into HCN, HCCCN, CH3CCCN, and CH2CCHCN, respectively. The values are consistent with statistical calculations based on new ab initio results at the CBS-QB3 level of theory. This work is a demonstration of CPUF as a powerful technique for quantitatively determining the branching into polyatomic products from a bimolecular reaction. |
| first_indexed | 2024-09-23T15:01:43Z |
| format | Article |
| id | mit-1721.1/105098 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:01:43Z |
| publishDate | 2016 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1050982022-10-02T00:04:39Z Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow Abeysekera, Chamara Joalland, Baptiste Ariyasingha, Nuwandi Zack, Lindsay N. Sims, Ian R. Suits, Arthur G. Field, Robert W Massachusetts Institute of Technology. Department of Chemistry Field, Robert W A new chirped-pulse/uniform flow (CPUF) spectrometer has been developed and used to determine product branching in a multichannel reaction. With this technique, bimolecular reactions can be initiated in a cold, thermalized, high-density molecular flow and a broadband microwave spectrum acquired for all products with rotational transitions within a chosen frequency window. In this work, the CN + CH3CCH reaction was found to yield HCN via a direct H-abstraction reaction, whereas indirect addition/elimination pathways to HCCCN, CH3CCCN, and CH2CCHCN were also probed. From these observations, quantitative branching ratios were established for all products as 12(5)%, 66(4)%, 22(6)%, and 0(8)% into HCN, HCCCN, CH3CCCN, and CH2CCHCN, respectively. The values are consistent with statistical calculations based on new ab initio results at the CBS-QB3 level of theory. This work is a demonstration of CPUF as a powerful technique for quantitatively determining the branching into polyatomic products from a bimolecular reaction. National Science Foundation (U.S.) (Award MRI-ID1126380) United States. Dept. of Energy. Office of Basic Energy Sciences (Joint Center for Energy Storage Research (Award DE FG02-04ER15593) 2016-10-26T18:26:31Z 2016-10-26T18:26:31Z 2015-04 2015-03 Article http://purl.org/eprint/type/JournalArticle 1948-7185 http://hdl.handle.net/1721.1/105098 Abeysekera, Chamara, Baptiste Joalland, Nuwandi Ariyasingha, Lindsay N. Zack, Ian R. Sims, Robert W. Field, and Arthur G. Suits. "Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow." Journal of Physical Chemistry Letters 6:9 (2015), pp. 1599-1604. © 2015 American Chemical Society. https://orcid.org/0000-0002-7609-4205 en_US http://dx.doi.org/10.1021/acs.jpclett.5b00519 Journal of Physical Chemistry Letters Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Chemical Society (ACS) ACS |
| spellingShingle | Abeysekera, Chamara Joalland, Baptiste Ariyasingha, Nuwandi Zack, Lindsay N. Sims, Ian R. Suits, Arthur G. Field, Robert W Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title | Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title_full | Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title_fullStr | Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title_full_unstemmed | Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title_short | Product Branching in the Low Temperature Reaction of CN with Propyne by Chirped-Pulse Microwave Spectroscopy in a Uniform Supersonic Flow |
| title_sort | product branching in the low temperature reaction of cn with propyne by chirped pulse microwave spectroscopy in a uniform supersonic flow |
| url | http://hdl.handle.net/1721.1/105098 https://orcid.org/0000-0002-7609-4205 |
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