Pulsed Dynamic Nuclear Polarization with Trityl Radicals

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Solid-State Physics
• Quantum Information Science

Background:

• Continuous-wave (CW) dynamic nuclear polarization (DNP) enhances NMR sensitivity but faces limitations.
• There is a need for more efficient polarization transfer methods, especially for pulsed DNP.
• Pulsed DNP methods offer rapid polarization transfer and are less affected by high magnetic fields compared to CW DNP.

Purpose of the Study:

• To investigate the efficiency of nuclear spin orientation via electron spin-locking (NOVEL) for dynamic nuclear polarization.
• To demonstrate the capability of NOVEL for rapid and efficient polarization transfer in a relevant solid-state DNP system.
• To establish a foundation for the application of pulsed DNP at higher magnetic fields.

Main Methods:

• Implementation of nuclear spin orientation via electron spin-locking (NOVEL) experiments.
• Utilizing the trityl OX063 polarizing agent in a glycerol/water matrix.
• Conducting experiments at a temperature of 80 K and a magnetic field of 0.34 T.

Main Results:

• Achieved significant (1)H NMR signal enhancements up to 430-fold.
• Observed rapid buildup of local polarization within a few hundred nanoseconds.
• Demonstrated efficient dynamic polarization of (1)H nuclei using the NOVEL technique.

Conclusions:

• NOVEL is an effective pulsed DNP method for enhancing (1)H NMR sensitivity.
• The observed rapid polarization buildup and high signal enhancements are promising for solid-state DNP NMR.
• This study represents a crucial advancement towards the widespread application of pulsed DNP at higher magnetic fields.