Study Of High-resolution Two-dimensional Nuclear Magnetic Resonance Spectroscopy Via Homonuclear Broadband Decoupling Module

Due to the high gyromagnetic ratio and natural abundance,proton is chosen as the major target nucleus to analyze the structure of the molecules.However,narrow chemical shift distribution and complex coupling splits causing frequent overlap limit its application.Therefore,abundant and creative high-resolution spectroscopic methods have been proposed,such as multi-dimensional spectroscopic methods and pure shift methods.Pure shift techniques can acquire the spectra without coupling effects.Recently,pure shift techniques have been attracting increasing researchers' attention because of its ability to be utilized in the multi-dimensional spectra as a module to acquire the pure shift spectra in direct dimension or to achieve typical chemical shift and coupling evolution.This paper mainly proposes two kinds of high-resolution NMR spectroscopic techniques via homonuclear broadband decoupling modules,including high-resolution two-dimensional(2D)nuclear magnetic resonance(NMR)spectroscopy based on Radon transformation,and the localized 2D phase-sensitive J-resolved magnetic resonance spectroscopy(PS-JPRESS).The main works are listed as below:In the first part of this thesis,a method to obtain high-resolution two-dimensional NMR spectroscopy by Radon transformation is proposed.This new method combines pure shift method and Radon transformation,which cannot only map the peaks chemical shift change rate caused by temperature,pH value,solvent and other factors,but also improve the efficiency of the assignment and reduce the experimental time.These advantages have been testified by two series of experiments including changing temperature and solvent's concentration.In the second part of this thesis,a PS-JPRESS method which brings phase sensitive NMR spectroscopic technique in localized nuclear magnetic resonance spectroscopy(MRS)is proposed to improve the low resolution in JPRESS spectra.Subsequent theoretical derivation and experiments testify the effectiveness of the method and show great potentials for further researches.