High-performance selective excitation pulses for solid- and liquid-state NMR spectroscopy

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Computational Chemistry
• Solid-State and Solution-State Chemistry

Background:

• Computer-optimized selective pulses are standard in solution-state NMR but underutilized in solid-state NMR.
• Designing effective selective pulses for solid-state applications remains a challenge.
• Existing methods lack the desired flexibility and performance for broad applicability.

Purpose of the Study:

• To introduce a novel computational strategy for designing soft selective pulses.
• To develop a new family of high-performance selective excitation pulses for NMR.
• To demonstrate the utility of these pulses in both solid-state and solution-state NMR.

Main Methods:

• A new computational approach was developed for designing soft selective pulses.
• The strategy was applied to the selective excitation problem, leading to the E-Family pulses.
• Theoretical treatment of chemical shift anisotropy (CSA) effects in magic-angle spinning (MAS) NMR was performed.
• The developed heuristics were integrated into the SPINEVOLUTION NMR simulation program.

Main Results:

• A new family of high-performance selective excitation pulses, termed E-Family, was designed.
• E-Family pulses offer greater flexibility and superior performance compared to existing pulses.
• Successful experimental validation of E-Family pulses in both solid-state and solution-state NMR.
• Theoretical framework for CSA effects on selective excitation in MAS NMR was established.

Conclusions:

• The new computational approach simplifies the design of effective soft selective pulses.
• The E-Family pulses represent a significant advancement in selective excitation for NMR.
• This work bridges the gap in the application of selective pulses between solution and solid states.