Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX
Three newly synthesized [Na+(221-Kryptofix)] salts containing AsCO–, PCO–, and PCS– anions were successfully electrosprayed into a vacuum, and these three ECX– anions were investigated by negative ion photoelectron spectroscopy (NIPES) along with high-resolution photoelectron imaging spectroscopy. F...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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American Chemical Society (ACS)
2018
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| Online Access: | http://hdl.handle.net/1721.1/116460 |
| _version_ | 1811077240092360704 |
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| author | Hou, Gao-Lei Chen, Bo Transue, Wesley J. Yang, Zheng Grützmacher, Hansjörg Driess, Matthias Cummins, Christopher C. Borden, Weston Thatcher Wang, Xue-Bin |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Hou, Gao-Lei Chen, Bo Transue, Wesley J. Yang, Zheng Grützmacher, Hansjörg Driess, Matthias Cummins, Christopher C. Borden, Weston Thatcher Wang, Xue-Bin |
| author_sort | Hou, Gao-Lei |
| collection | MIT |
| description | Three newly synthesized [Na+(221-Kryptofix)] salts containing AsCO–, PCO–, and PCS– anions were successfully electrosprayed into a vacuum, and these three ECX– anions were investigated by negative ion photoelectron spectroscopy (NIPES) along with high-resolution photoelectron imaging spectroscopy. For each ECX– anion, a well-resolved NIPE spectrum was obtained, in which every major peak is split into a doublet. The splittings are attributed to spin–orbit coupling (SOC) in the ECX• radicals. Vibrational progressions in the NIPE spectra of ECX– were assigned to the symmetric and the antisymmetric stretching modes in ECX• radicals. The electron affinities (EAs) and SO splittings of ECX• are determined from the NIPE spectra to be AsCO•: EA = 2.414 ± 0.002 eV, SO splitting = 988 cm–1; PCO•: EA = 2.670 ± 0.005 eV, SO splitting = 175 cm–1; PCS•: EA = 2.850 ± 0.005 eV, SO splitting = 300 cm–1. Calculations using the B3LYP, CASPT2, and CCSD(T) methods all predict linear geometries for both the anions and the neutral radicals. The calculated EAs and SO splittings for ECX• are in excellent agreement with the experimentally measured values. The simulated NIPE spectra, which are based on the calculated Franck–Condon factors, and the SO splittings nicely reproduce all of the observed spectral peaks, thus allowing unambiguous spectral assignments. The finding that PCS• has the greatest EA of the three triatomic molecules considered here is counterintuitive based upon simple electronegativity considerations, but this finding is understandable in terms of the movement of electron density from phosphorus in the HOMO of PCO– to sulfur in the HOMO of PCS–. Comparisons of the EAs of PCO• and PCS• with the previously measured EA values for NCO• and NCS• are made and discussed. |
| first_indexed | 2024-09-23T10:39:52Z |
| format | Article |
| id | mit-1721.1/116460 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:39:52Z |
| publishDate | 2018 |
| publisher | American Chemical Society (ACS) |
| record_format | dspace |
| spelling | mit-1721.1/1164602022-09-30T22:07:46Z Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX Hou, Gao-Lei Chen, Bo Transue, Wesley J. Yang, Zheng Grützmacher, Hansjörg Driess, Matthias Cummins, Christopher C. Borden, Weston Thatcher Wang, Xue-Bin Massachusetts Institute of Technology. Department of Chemistry Cummins, Christopher C. Cummins, Christopher C. Three newly synthesized [Na+(221-Kryptofix)] salts containing AsCO–, PCO–, and PCS– anions were successfully electrosprayed into a vacuum, and these three ECX– anions were investigated by negative ion photoelectron spectroscopy (NIPES) along with high-resolution photoelectron imaging spectroscopy. For each ECX– anion, a well-resolved NIPE spectrum was obtained, in which every major peak is split into a doublet. The splittings are attributed to spin–orbit coupling (SOC) in the ECX• radicals. Vibrational progressions in the NIPE spectra of ECX– were assigned to the symmetric and the antisymmetric stretching modes in ECX• radicals. The electron affinities (EAs) and SO splittings of ECX• are determined from the NIPE spectra to be AsCO•: EA = 2.414 ± 0.002 eV, SO splitting = 988 cm–1; PCO•: EA = 2.670 ± 0.005 eV, SO splitting = 175 cm–1; PCS•: EA = 2.850 ± 0.005 eV, SO splitting = 300 cm–1. Calculations using the B3LYP, CASPT2, and CCSD(T) methods all predict linear geometries for both the anions and the neutral radicals. The calculated EAs and SO splittings for ECX• are in excellent agreement with the experimentally measured values. The simulated NIPE spectra, which are based on the calculated Franck–Condon factors, and the SO splittings nicely reproduce all of the observed spectral peaks, thus allowing unambiguous spectral assignments. The finding that PCS• has the greatest EA of the three triatomic molecules considered here is counterintuitive based upon simple electronegativity considerations, but this finding is understandable in terms of the movement of electron density from phosphorus in the HOMO of PCO– to sulfur in the HOMO of PCS–. Comparisons of the EAs of PCO• and PCS• with the previously measured EA values for NCO• and NCS• are made and discussed. National Science Foundation (U.S.) (Grant CHE-1362118) 2018-06-21T13:41:10Z 2018-06-21T13:41:10Z 2017-07 2017-03 Article http://purl.org/eprint/type/JournalArticle 0002-7863 1520-5126 http://hdl.handle.net/1721.1/116460 Hou, Gao-Lei et al. “Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX– (E = As, P, and N; X = S and O) Anions.” Journal of the American Chemical Society 139, 26 (June 2017): 8922–8930 © 2017 American Chemical Society en_US http://dx.doi.org/10.1021/jacs.7b02984 Journal of the American Chemical Society 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) Prof. Cummins via Erja Kajosalo |
| spellingShingle | Hou, Gao-Lei Chen, Bo Transue, Wesley J. Yang, Zheng Grützmacher, Hansjörg Driess, Matthias Cummins, Christopher C. Borden, Weston Thatcher Wang, Xue-Bin Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title | Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title_full | Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title_fullStr | Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title_full_unstemmed | Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title_short | Spectroscopic Characterization, Computational Investigation, and Comparisons of ECX |
| title_sort | spectroscopic characterization computational investigation and comparisons of ecx |
| url | http://hdl.handle.net/1721.1/116460 |
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