An automated multi-order phase correction routine for processing ultra-wideline NMR spectra

Area of Science:

• Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
• Advanced Spectroscopic Data Processing
• Materials Characterization

Background:

• Wideline solid-state NMR spectra often suffer from inhomogeneous broadening, leading to complex phase distortions.
• Conventional processing discards phase information by using magnitude calculations, limiting spectral accuracy.
• Frequency-swept pulses in broadband sequences exacerbate phase distortions due to interactions with anisotropic resonance frequencies.

Purpose of the Study:

• To develop a fully automated phasing routine for processing and phase correcting wideline solid-state NMR spectra.
• To address the challenges of multi-order non-linear phase corrections in NMR data.
• To improve the quality and interpretability of NMR spectra affected by significant broadening and phase distortions.

Main Methods:

• Development and implementation of a fully automated phase correction algorithm.
• Validation using simulated and experimental NMR datasets across various nuclei (¹¹⁹Sn, ¹⁹⁵Pt, ³⁵Cl, ⁸⁷Rb, ¹⁴N).
• Testing with data acquired using WURST-CPMG and BRAIN-CP broadband pulse sequences.

Main Results:

• The automated routine successfully performs phase corrections up to second order without requiring prior information.
• Processed spectra exhibit improved signal-to-noise ratios compared to conventional magnitude calculations.
• Obtained powder patterns more closely resemble ideal NMR spectra, even for low signal-to-noise or artifact-affected datasets.

Conclusions:

• The automated phasing routine provides an effective solution for processing challenging wideline solid-state NMR spectra.
• This method enhances spectral fidelity and quantitative analysis capabilities in solid-state NMR.
• The routine is robust and applicable across different nuclei and acquisition methods, simplifying data analysis.