The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field
Ammonia is special. It is nonplanar, yet in v = 1 of the umbrella mode (ν2) its inversion motion is faster than J = 0↔1 rotation. Does the simplicity of the Chemist’s concept of an electric dipole moment survive the competition between rotation, inversion, and a strong external electric field? NH3 i...
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
National Academy of Sciences
2020
|
| Online Access: | https://hdl.handle.net/1721.1/126151 |
| _version_ | 1826197430832463872 |
|---|---|
| author | Park, Youngwook Kang, Hani Field, Robert W Kang, Heon |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Park, Youngwook Kang, Hani Field, Robert W Kang, Heon |
| author_sort | Park, Youngwook |
| collection | MIT |
| description | Ammonia is special. It is nonplanar, yet in v = 1 of the umbrella mode (ν2) its inversion motion is faster than J = 0↔1 rotation. Does the simplicity of the Chemist’s concept of an electric dipole moment survive the competition between rotation, inversion, and a strong external electric field? NH3 is a favorite pedagogical example of tunneling in a symmetric double-minimum potential. Tunneling is a dynamical concept, yet the quantitative characteristics of tunneling are expressed in a static, eigenstate-resolved spectrum. The inverting-umbrella tunneling motion in ammonia is both large amplitude and profoundly affected by an external electric field. We report how a uniquely strong (up to 108 V/m) direct current (DC) electric field causes a richly detailed sequence of reversible changes in the frequency-domain infrared spectrum (the v = 0→1 transition in the ν2 umbrella mode) of ammonia, freely rotating in a 10 K Ar matrix. Although the spectrum is static, encoded in it is the complete inter- and intramolecular picture of tunneling dynamics. |
| first_indexed | 2024-09-23T10:47:33Z |
| format | Article |
| id | mit-1721.1/126151 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T10:47:33Z |
| publishDate | 2020 |
| publisher | National Academy of Sciences |
| record_format | dspace |
| spelling | mit-1721.1/1261512022-09-27T15:02:57Z The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field Park, Youngwook Kang, Hani Field, Robert W Kang, Heon Massachusetts Institute of Technology. Department of Chemistry Ammonia is special. It is nonplanar, yet in v = 1 of the umbrella mode (ν2) its inversion motion is faster than J = 0↔1 rotation. Does the simplicity of the Chemist’s concept of an electric dipole moment survive the competition between rotation, inversion, and a strong external electric field? NH3 is a favorite pedagogical example of tunneling in a symmetric double-minimum potential. Tunneling is a dynamical concept, yet the quantitative characteristics of tunneling are expressed in a static, eigenstate-resolved spectrum. The inverting-umbrella tunneling motion in ammonia is both large amplitude and profoundly affected by an external electric field. We report how a uniquely strong (up to 108 V/m) direct current (DC) electric field causes a richly detailed sequence of reversible changes in the frequency-domain infrared spectrum (the v = 0→1 transition in the ν2 umbrella mode) of ammonia, freely rotating in a 10 K Ar matrix. Although the spectrum is static, encoded in it is the complete inter- and intramolecular picture of tunneling dynamics. NSF (grant no. CHE-1800410) 2020-07-13T15:23:36Z 2020-07-13T15:23:36Z 2019-11 2019-12-17T17:30:22Z Article http://purl.org/eprint/type/JournalArticle 1091-6490 https://hdl.handle.net/1721.1/126151 Park, Youngwook, et al. "The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field." Proceedings of the National Academy of Science of the United States of America 116, 47 (2019): p. 23444-47 doi 10.1073/pnas.1914432116 ©2019 Author(s) en 10.1073/pnas.1914432116 Proceedings of the National Academy of Science of the United States of America 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 National Academy of Sciences PNAS |
| spellingShingle | Park, Youngwook Kang, Hani Field, Robert W Kang, Heon The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title | The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title_full | The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title_fullStr | The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title_full_unstemmed | The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title_short | The frequency-domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a DC electric field |
| title_sort | frequency domain infrared spectrum of ammonia encodes changes in molecular dynamics caused by a dc electric field |
| url | https://hdl.handle.net/1721.1/126151 |
| work_keys_str_mv | AT parkyoungwook thefrequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT kanghani thefrequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT fieldrobertw thefrequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT kangheon thefrequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT parkyoungwook frequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT kanghani frequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT fieldrobertw frequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield AT kangheon frequencydomaininfraredspectrumofammoniaencodeschangesinmoleculardynamicscausedbyadcelectricfield |