Chrome Extension
WeChat Mini Program
Use on ChatGLM

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.

JOURNAL OF PHYSICAL CHEMISTRY B(2018)

Cited 23|Views38
No score
Abstract
The F-19 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. Significant narrowing of the 19F lines was observed under fast MAS conditions, at spinning frequencies above 50 kHz. The parameters characterizing the 19F 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 F-19 magnetic shielding tensors require the PBEO 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 19F based MAS NMR structural analysis of proteins and protein assemblies.
More
Translated text
Key words
fluorosubstituted tryptophans,nmr,density functional theory calculations,spectroscopy
AI Read Science
Must-Reading Tree
Example
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined