(19)F Magic Angle Spinning NMR Spectroscopy and Density Functional Theory Calculations of Fluorosubstituted Tryptophans: Integrating Experiment and Theory for Accurate Determination of Chemical Shift Tensors
| Autor: | Tatyana Polenova, Cecil Dybowski, Angela M. Gronenborn, Sucharita Sarkar, Manman Lu, Jodi Kraus, Sean T. Holmes, Werner E. Maas, Ivan V. Sergeyev, Jochem Struppe, Matthew Fritz, Caitlin M. Quinn, Mingzhang Wang, Shi Bai, Glenn P. A. Yap |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
010405 organic chemistry Nuclear magnetic resonance spectroscopy Crystal structure 010402 general chemistry 01 natural sciences Article 0104 chemical sciences Surfaces Coatings and Films Chemical physics Materials Chemistry Magic angle spinning Molecule Density functional theory Tensor Physical and Theoretical Chemistry Chirality (chemistry) Spinning |
| Popis: | The (19)F chemical shift is a sensitive NMR probe of structure and electronic environment in organic and biological molecules. In this report we examine chemical shift parameters of 4F-, 5F-, 6F-, and 7F-substituted crystalline tryptophan by magic angle spinning (MAS) solid-state NMR spectroscopy and density functional theory (DFT). Significant narrowing of the (19)F lines was observed under fast MAS conditions, at spinning frequencies above 50 kHz. The parameters characterizing the (19)F chemical shift tensor are sensitive to the position of the fluorine in the aromatic ring and, to a lesser extent, the chirality of the molecule. Accurate calculations of (19)F magnetic shielding tensors require the PBE0 functional with a 50% admixture of a Hartree-Fock exchange term, as well as taking account of the local crystal symmetry. The methodology developed will be beneficial for (19)F-based MAS NMR structural analysis of proteins and protein assemblies. |
| Databáze: | OpenAIRE |
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