The Experts below are selected from a list of 4668 Experts worldwide ranked by ideXlab platform

Jack H. Freed - One of the best experts on this subject based on the ideXlab platform.

  • NUCLEAR MODULATION EFFECTS IN 2+1 ELECTRON Spin-Echo CORRELATION Spectroscopy
    The Journal of Chemical Physics, 1995
    Co-Authors: Arnold Raitsimring, Richard H. Crepeau, Jack H. Freed
    Abstract:

    This work represents the synthesis of the 2+1 pulse sequence for the study of electron spin‐echo envelope modulation (ESEEM) with the technique of spin‐echo Correlated Spectroscopy (SECSY), which has previously been used to study nuclear modulation by two‐dimensional Fourier transform ESR methods. This example of ‘‘pulse adjustable’’ Spectroscopy, wherein the pulse width and pulse amplitude of the second pulse in a three pulse sequence are introduced as adjustable parameters, leads to enhanced resolution to the key features of the nuclear modulation that are important for structural studies. This is demonstrated in studies on (i) a single crystal of irradiated malonic acid and (ii) a frozen solution of diphenylpicrylhydrazyl in toluene. In particular, it is shown for (i) how the nuclear modulation cross peaks can be preferentially enhanced relative to the autopeaks and to the matrix proton peaks, and also how the autopeaks can be significantly suppressed to enhance resolution for low‐frequency cross peaks...

Zhong Chen - One of the best experts on this subject based on the ideXlab platform.

  • Improving spectral resolution in spatial encoding dimension of single-scan nuclear magnetic resonance 2D spin echo Correlated Spectroscopy
    Molecular Physics, 2014
    Co-Authors: Liangjie Lin, Zhiliang Wei, Jian Yang, Yanqin Lin, Zhong Chen
    Abstract:

    The spatial encoding technique can be used to accelerate the acquisition of multi-dimensional nuclear magnetic resonance spectra. However, with this technique, we have to make trade-offs between the spectral width and the resolution in the spatial encoding dimension (F1 dimension), resulting in the difficulty of covering large spectral widths while preserving acceptable resolutions for spatial encoding spectra. In this study, a selective shifting method is proposed to overcome the aforementioned drawback. This method is capable of narrowing spectral widths and improving spectral resolutions in spatial encoding dimensions by selectively shifting certain peaks in spectra of the ultrafast version of spin echo Correlated Spectroscopy (UFSECSY). This method can also serve as a powerful tool to obtain high-resolution Correlated spectra in inhomogeneous magnetic fields for its resistance to any inhomogeneity in the F1 dimension inherited from UFSECSY. Theoretical derivations and experiments have been carried out...

Arnold Raitsimring - One of the best experts on this subject based on the ideXlab platform.

  • NUCLEAR MODULATION EFFECTS IN 2+1 ELECTRON Spin-Echo CORRELATION Spectroscopy
    The Journal of Chemical Physics, 1995
    Co-Authors: Arnold Raitsimring, Richard H. Crepeau, Jack H. Freed
    Abstract:

    This work represents the synthesis of the 2+1 pulse sequence for the study of electron spin‐echo envelope modulation (ESEEM) with the technique of spin‐echo Correlated Spectroscopy (SECSY), which has previously been used to study nuclear modulation by two‐dimensional Fourier transform ESR methods. This example of ‘‘pulse adjustable’’ Spectroscopy, wherein the pulse width and pulse amplitude of the second pulse in a three pulse sequence are introduced as adjustable parameters, leads to enhanced resolution to the key features of the nuclear modulation that are important for structural studies. This is demonstrated in studies on (i) a single crystal of irradiated malonic acid and (ii) a frozen solution of diphenylpicrylhydrazyl in toluene. In particular, it is shown for (i) how the nuclear modulation cross peaks can be preferentially enhanced relative to the autopeaks and to the matrix proton peaks, and also how the autopeaks can be significantly suppressed to enhance resolution for low‐frequency cross peaks...

Liangjie Lin - One of the best experts on this subject based on the ideXlab platform.

  • Improving spectral resolution in spatial encoding dimension of single-scan nuclear magnetic resonance 2D spin echo Correlated Spectroscopy
    Molecular Physics, 2014
    Co-Authors: Liangjie Lin, Zhiliang Wei, Jian Yang, Yanqin Lin, Zhong Chen
    Abstract:

    The spatial encoding technique can be used to accelerate the acquisition of multi-dimensional nuclear magnetic resonance spectra. However, with this technique, we have to make trade-offs between the spectral width and the resolution in the spatial encoding dimension (F1 dimension), resulting in the difficulty of covering large spectral widths while preserving acceptable resolutions for spatial encoding spectra. In this study, a selective shifting method is proposed to overcome the aforementioned drawback. This method is capable of narrowing spectral widths and improving spectral resolutions in spatial encoding dimensions by selectively shifting certain peaks in spectra of the ultrafast version of spin echo Correlated Spectroscopy (UFSECSY). This method can also serve as a powerful tool to obtain high-resolution Correlated spectra in inhomogeneous magnetic fields for its resistance to any inhomogeneity in the F1 dimension inherited from UFSECSY. Theoretical derivations and experiments have been carried out...

Richard H. Crepeau - One of the best experts on this subject based on the ideXlab platform.

  • NUCLEAR MODULATION EFFECTS IN 2+1 ELECTRON Spin-Echo CORRELATION Spectroscopy
    The Journal of Chemical Physics, 1995
    Co-Authors: Arnold Raitsimring, Richard H. Crepeau, Jack H. Freed
    Abstract:

    This work represents the synthesis of the 2+1 pulse sequence for the study of electron spin‐echo envelope modulation (ESEEM) with the technique of spin‐echo Correlated Spectroscopy (SECSY), which has previously been used to study nuclear modulation by two‐dimensional Fourier transform ESR methods. This example of ‘‘pulse adjustable’’ Spectroscopy, wherein the pulse width and pulse amplitude of the second pulse in a three pulse sequence are introduced as adjustable parameters, leads to enhanced resolution to the key features of the nuclear modulation that are important for structural studies. This is demonstrated in studies on (i) a single crystal of irradiated malonic acid and (ii) a frozen solution of diphenylpicrylhydrazyl in toluene. In particular, it is shown for (i) how the nuclear modulation cross peaks can be preferentially enhanced relative to the autopeaks and to the matrix proton peaks, and also how the autopeaks can be significantly suppressed to enhance resolution for low‐frequency cross peaks...