The 1H and 13C chemical shifts of 5–5 lignin model dimers: An evaluation of DFT functionals
| Autor: | Thien T. Nguyen, Jussi Sipilä, Jussi Helminen, Phong Quoc Le |
|---|---|
| Přispěvatelé: | Department of Chemistry, Jussi Sipilä / Principal Investigator |
| Rok vydání: | 2021 |
| Předmět: |
NMR chemical shift
5-5 lignin model dimer 116 Chemical sciences 010402 general chemistry 01 natural sciences Spectral line Analytical Chemistry Inorganic Chemistry Ferulic acid chemistry.chemical_compound Generalized gradient DFT functionals Atomic orbital Computational chemistry SPECTRA Lignin EXCHANGE Spectroscopy 010405 organic chemistry Chemical shift HYDRODEOXYGENATION Organic Chemistry Oxidative coupling CORRELATION-ENERGY Carbon-13 NMR GENERALIZED GRADIENT APPROXIMATION 0104 chemical sciences chemistry ACID Oxidative coupling of methane BEHAVIOR |
| Zdroj: | Journal of Molecular Structure. 1226:129300 |
| ISSN: | 0022-2860 |
| DOI: | 10.1016/j.molstruc.2020.129300 |
| Popis: | The calculations of 1H and 13C NMR chemical shifts were performed on three 5–5 lignin dimers, prominent substructures in softwood lignins, to compare with experimental data. Initially, 10 DFT functionals (B3LYP, B3PW91, BPV86, CAM-B3LYP, HCTH, HSEH1PBE, mPW1PW91, PBEPBE, TPSSTPSS, and ωB97XD) combined with the gage-including atomic orbital (GIAO) method and basic set 6–31G(d,p) were tested on 3,3′-(6,6′-dihydroxy-5,5′-dimethoxy-[1,1′-biphenyl]-3,3′-diyl)dipropionic acid (1), efficiently synthesized from ferulic acid. HSEH1PBE, mPW1PW91, and ωB97XD were found to be the three best performing functionals with strong correlations (r2 ≥ 0.9988) and low errors (CMAEs ≤ 0.0611 ppm for 1H and CMAEs ≤ 1.19 ppm for 13C). These functionals were also well-performed for the 1H and 13C shift calculations of dimers 3,3′-dimethoxy-5,5′-dimethyl-[1,1′-biphenyl]-2,2′-diol (2) and 5,5′-diallyl-3,3′-dimethoxy-[1,1′-biphenyl]-2,2′-diol (3). Overall, the ωB97XD functional consistently provided the calculated 1H and 13C chemical shifts with a high level of accuracy. |
| Databáze: | OpenAIRE |
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