Relaxation-induced dipolar exchange with recoupling-An MAS NMR method for determining heteronuclear distances without...

Area of Science:

• Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
• Materials Science
• Chemical Physics

Background:

• Determining distances between unlike spins in solid materials is crucial for structural analysis.
• Conventional methods often require complex experimental setups or are limited by specific nuclear properties.

Purpose of the Study:

• Introduce a novel magic-angle spinning NMR method for heteronuclear distance determination.
• Develop a technique that is less sensitive to quadrupolar interactions and relaxation properties.

Main Methods:

• Utilized Relaxation-Induced Dipolar Exchange with Recoupling (RIDER) experiments.
• Employed conventional double-resonance equipment and pi-pulse trains for recoupling heteronuclear dipolar interactions.
• Analyzed dephasing curves similar to the Rotational Echo Double Resonance (REDOR) experiment.

Main Results:

• Successfully measured distances between unlike spins, including (13)C with (14)N and (2)H.
• Demonstrated that RIDER dephasing curves depend on passive spin relaxation times, enabling their estimation.
• Showed the method is largely independent of quadrupolar interactions for the passive spin.

Conclusions:

• RIDER is an effective and versatile method for heteronuclear distance measurements in solid-state NMR.
• The technique offers an advantage for determining distances to quadrupolar nuclei.
• RIDER provides a pathway for estimating longitudinal relaxation times of passive spins.