The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1]
The ungerade vibrational levels of the [~ over A] [superscript 1]A[subscript u] (S[subscript 1]-trans) state of C[subscript 2]H[subscript 2] lying in the region 45,800–46,550 cm[superscript −1] have been assigned from IR–UV double resonance spectra. The aim has been to classify the complete manifold...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Taylor & Francis
2015
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| Online Access: | http://hdl.handle.net/1721.1/95912 https://orcid.org/0000-0002-7609-4205 |
| _version_ | 1826204291522625536 |
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| author | Merer, Anthony J. Field, Robert W. Baraban, Joshua H. Changala, Peter Bryan Steeves, Adam Bechtel, Hans A. |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Merer, Anthony J. Field, Robert W. Baraban, Joshua H. Changala, Peter Bryan Steeves, Adam Bechtel, Hans A. |
| author_sort | Merer, Anthony J. |
| collection | MIT |
| description | The ungerade vibrational levels of the [~ over A] [superscript 1]A[subscript u] (S[subscript 1]-trans) state of C[subscript 2]H[subscript 2] lying in the region 45,800–46,550 cm[superscript −1] have been assigned from IR–UV double resonance spectra. The aim has been to classify the complete manifold of S[subscript 1]-trans levels in this region, so as to facilitate the assignment of the bands of S[subscript 1]-cis C[subscript 2]H[subscript 2]. The rotational structure is complicated because of the overlapping of vibrational polyads with different Coriolis and Darling–Dennison parameters, but assignments have been possible with the help of predictions based on the properties of polyads at lower energy. An important result is that the analysis of the (1[superscript 1]4[superscript 1], 1[superscript 1]6[superscript 1]) polyad determines the anharmonicity constants x [subscript 14] and x [subscript 16], which will be needed to proceed to higher energies. Some regions of impressive complexity occur. Among these is the band given by the 3[superscript 3]6[superscript 1], K = 1 state at 45,945 cm[superscript −1], where a three-level interaction within the S[subscript 1] state is confused by triplet perturbations. Several probable S[subscript 1]-cis states have been observed, including cis-6[superscript 2], K = 1; this vibrational level appears to show a K-staggering, of the type that arises when quantum mechanical tunnelling through the barrier to cis-trans isomerization is possible. The total number of identified cis vibrational states is now 6 out of an expected 10 up to the energies discussed in this paper. |
| first_indexed | 2024-09-23T12:51:58Z |
| format | Article |
| id | mit-1721.1/95912 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:51:58Z |
| publishDate | 2015 |
| publisher | Taylor & Francis |
| record_format | dspace |
| spelling | mit-1721.1/959122022-09-28T10:33:01Z The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] Merer, Anthony J. Field, Robert W. Baraban, Joshua H. Changala, Peter Bryan Steeves, Adam Bechtel, Hans A. Massachusetts Institute of Technology. Department of Chemistry Field, Robert W. Baraban, Joshua H. Changala, Peter Bryan Steeves, Adam Bechtel, Hans A. Field, Robert W. The ungerade vibrational levels of the [~ over A] [superscript 1]A[subscript u] (S[subscript 1]-trans) state of C[subscript 2]H[subscript 2] lying in the region 45,800–46,550 cm[superscript −1] have been assigned from IR–UV double resonance spectra. The aim has been to classify the complete manifold of S[subscript 1]-trans levels in this region, so as to facilitate the assignment of the bands of S[subscript 1]-cis C[subscript 2]H[subscript 2]. The rotational structure is complicated because of the overlapping of vibrational polyads with different Coriolis and Darling–Dennison parameters, but assignments have been possible with the help of predictions based on the properties of polyads at lower energy. An important result is that the analysis of the (1[superscript 1]4[superscript 1], 1[superscript 1]6[superscript 1]) polyad determines the anharmonicity constants x [subscript 14] and x [subscript 16], which will be needed to proceed to higher energies. Some regions of impressive complexity occur. Among these is the band given by the 3[superscript 3]6[superscript 1], K = 1 state at 45,945 cm[superscript −1], where a three-level interaction within the S[subscript 1] state is confused by triplet perturbations. Several probable S[subscript 1]-cis states have been observed, including cis-6[superscript 2], K = 1; this vibrational level appears to show a K-staggering, of the type that arises when quantum mechanical tunnelling through the barrier to cis-trans isomerization is possible. The total number of identified cis vibrational states is now 6 out of an expected 10 up to the energies discussed in this paper. United States. Dept. of Energy (Grant DE-FG0287ER13671) Massachusetts Institute of Technology. Undergraduate Research Opportunities Program 2015-03-06T19:50:02Z 2015-03-06T19:50:02Z 2012-11 2012-04 Article http://purl.org/eprint/type/JournalArticle 0026-8976 1362-3028 http://hdl.handle.net/1721.1/95912 Baraban, Joshua H., P. Bryan Changala, Anthony J. Merer, Adam H. Steeves, Hans A. Bechtel, and Robert W. Field. “The [~ over A][superscript 1]A[subscript u] State of Acetylene: Ungerade Vibrational Levels in the Region 45,800–46,550 cm[superscript −1].” Molecular Physics 110, no. 21–22 (November 2012): 2707–2723. https://orcid.org/0000-0002-7609-4205 en_US http://dx.doi.org/10.1080/00268976.2012.706329 Molecular Physics Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Taylor & Francis Field |
| spellingShingle | Merer, Anthony J. Field, Robert W. Baraban, Joshua H. Changala, Peter Bryan Steeves, Adam Bechtel, Hans A. The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title | The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title_full | The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title_fullStr | The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title_full_unstemmed | The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title_short | The [~ over A][superscript 1]A[subscript u] state of acetylene: ungerade vibrational levels in the region 45,800-46,550 cm[superscript -1] |
| title_sort | over a superscript 1 a subscript u state of acetylene ungerade vibrational levels in the region 45 800 46 550 cm superscript 1 |
| url | http://hdl.handle.net/1721.1/95912 https://orcid.org/0000-0002-7609-4205 |
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