Spectral editing in 13C solid-state NMR at high magnetic field using fast MAS and spin-echo dephasing

• Published in: Solid state nuclear magnetic resonance Vol. 47-48; pp. 19 - 22
• Main Authors: Mao, Kanmi, Kennedy, Gordon J., Althaus, Stacey M., Pruski, Marek
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.10.2012
• Subjects: Aromatic carbon; Carbon; Evolution; Fast MAS; Magnetic fields; Nuclear magnetic resonance; Rotating; Rotational; Solid-state NMR; Spectra; Spectral editing; Spin-echo dephasing; Strategy; Spectral editing; Solid-state NMR; Aromatic carbon; Spin-echo dephasing; Fast MAS
• ISSN: 0926-2040; 1527-3326
• DOI: 10.1016/j.ssnmr.2012.07.003

A simple method is proposed for separating NMR resonances from protonated and non-protonated aromatic carbons in solids under fast magic angle spinning (MAS). The approach uses a MAS-synchronized spin-echo to exploit the differences in rotational recoupling of the dipolar interactions while fully refocusing the isotropic chemical shifts. This strategy extends the relevant time scale of spin evolution to milliseconds and circumvents the limitation of the traditional dipolar dephasing method, which in fast rotating solids is disrupted by rotational refocusing. The proposed approach can be used for quantitative measurement of carbon aromaticities in complex solids with poorly resolved spectra, as demonstrated for model compounds. [Display omitted] ► We propose a simple method for distinguishing protonated and non-protonated aromatic carbons under fast MAS. ► The approach uses MAS-synchronized spin-echo to exploit the differences in rotational recoupling. This strategy circumvents the rotational echo problem in the traditional dipolar dephasing method. ► The approach can be used for quantification of carbon aromaticities in complex solids.