Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study
© 2017, The Author(s). The doublet C4 peaks at ~ 85 and ~ 89 ppm in solid-state 13C NMR spectra of native cellulose have been attributed to signals of C4 atoms on the surface (solvent-exposed) and in the interior of microfibrils, designated as sC4 and iC4, respectively. The relative intensity ratios...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Springer Science and Business Media LLC
2022
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| Online Access: | https://hdl.handle.net/1721.1/141069.2 |
| _version_ | 1811093619541540864 |
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| author | Yang, Hui Wang, Tuo Oehme, Daniel Petridis, Loukas Hong, Mei Kubicki, James D. |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Yang, Hui Wang, Tuo Oehme, Daniel Petridis, Loukas Hong, Mei Kubicki, James D. |
| author_sort | Yang, Hui |
| collection | MIT |
| description | © 2017, The Author(s). The doublet C4 peaks at ~ 85 and ~ 89 ppm in solid-state 13C NMR spectra of native cellulose have been attributed to signals of C4 atoms on the surface (solvent-exposed) and in the interior of microfibrils, designated as sC4 and iC4, respectively. The relative intensity ratios of sC4 and iC4 observed in NMR spectra of cellulose have been used to estimate the degree of crystallinity of cellulose and the number of glucan chains in cellulose microfibrils. However, the molecular structures of cellulose responsible for the specific surface and interior C4 peaks have not been positively confirmed. Using density functional theory (DFT) methods and structures produced from classical molecular dynamics simulations, we investigated how the following four factors affect 13C NMR chemical shifts in cellulose: conformations of exocyclic groups at C6 (tg, gt and gg), H2O molecules H-bonded on the surface of the microfibril, glycosidic bond angles (Φ, Ψ) and the distances between H4 and HO3 atoms. We focus on changes in the δ13C4 value because it is the most significant observable for the same C atom within the cellulose structure. DFT results indicate that different conformations of the exocyclic groups at C6 have the greatest influence on δ13C4 peak separation, while the other three factors have secondary effects that increase the spread of the calculated C4 interior and surface peaks. |
| first_indexed | 2024-09-23T15:47:59Z |
| format | Article |
| id | mit-1721.1/141069.2 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T15:47:59Z |
| publishDate | 2022 |
| publisher | Springer Science and Business Media LLC |
| record_format | dspace |
| spelling | mit-1721.1/141069.22024-06-14T16:03:26Z Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study Yang, Hui Wang, Tuo Oehme, Daniel Petridis, Loukas Hong, Mei Kubicki, James D. Massachusetts Institute of Technology. Department of Chemistry © 2017, The Author(s). The doublet C4 peaks at ~ 85 and ~ 89 ppm in solid-state 13C NMR spectra of native cellulose have been attributed to signals of C4 atoms on the surface (solvent-exposed) and in the interior of microfibrils, designated as sC4 and iC4, respectively. The relative intensity ratios of sC4 and iC4 observed in NMR spectra of cellulose have been used to estimate the degree of crystallinity of cellulose and the number of glucan chains in cellulose microfibrils. However, the molecular structures of cellulose responsible for the specific surface and interior C4 peaks have not been positively confirmed. Using density functional theory (DFT) methods and structures produced from classical molecular dynamics simulations, we investigated how the following four factors affect 13C NMR chemical shifts in cellulose: conformations of exocyclic groups at C6 (tg, gt and gg), H2O molecules H-bonded on the surface of the microfibril, glycosidic bond angles (Φ, Ψ) and the distances between H4 and HO3 atoms. We focus on changes in the δ13C4 value because it is the most significant observable for the same C atom within the cellulose structure. DFT results indicate that different conformations of the exocyclic groups at C6 have the greatest influence on δ13C4 peak separation, while the other three factors have secondary effects that increase the spread of the calculated C4 interior and surface peaks. 2022-03-23T15:16:19Z 2022-03-08T20:28:58Z 2022-03-23T15:16:19Z 2017-11 2017-05 2022-03-08T20:23:33Z Article http://purl.org/eprint/type/JournalArticle 0969-0239 1572-882X https://hdl.handle.net/1721.1/141069.2 Yang, Hui, Wang, Tuo, Oehme, Daniel, Petridis, Loukas, Hong, Mei et al. 2018. "Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study." Cellulose, 25 (1). en http://dx.doi.org/10.1007/s10570-017-1549-6 Cellulose Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/octet-stream Springer Science and Business Media LLC Springer |
| spellingShingle | Yang, Hui Wang, Tuo Oehme, Daniel Petridis, Loukas Hong, Mei Kubicki, James D. Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title | Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title_full | Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title_fullStr | Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title_full_unstemmed | Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title_short | Structural factors affecting 13C NMR chemical shifts of cellulose: a computational study |
| title_sort | structural factors affecting 13c nmr chemical shifts of cellulose a computational study |
| url | https://hdl.handle.net/1721.1/141069.2 |
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