Radio-frequency (rf) field inhomogeneity is a common problem in NMR which leads to non-ideal rotations of spins in parts of the sample. Often, a physical volume restriction of the sample is used to reduce the effects of rf-field inhomogeneity, especially in solid-state NMR where spacers are inserted to reduce the sample volume to the centre of the coil. We show that band-selective pulses in the spin-lock frame can be used to apply B1-field selective inversions to spins that experience selected parts of the rf-field distribution. Any frequency band-selective pulse can be used for this purpose, but we chose the family of I-BURP pulses (Geen and Freeman, 1991) for the measurements demonstrated here. As an example, we show that the implementation of such pulses improves homonuclear frequency-switched Lee-Goldburg decoupling in solid-state NMR.

Department of Chemistry Faculty of Science Charles University Hlavova 8 12842 Prague 2 Czech Republic

Physical Chemistry ETH Zürich Vladimir Prelog Weg 2 8093 Zürich Switzerland

Zobrazit více v PubMed

Aebischer K, Wili N, Tošner Z, Ernst M. 2020. Using nutation-frequency-selective pulses to reduce radio-frequency field inhomogeneity in solid-state NMR. ETH Zürich. PubMed DOI PMC

Bielecki A, Kolbert A, Levitt MH. Frequency-Switched Pulse Sequences – Homonuclear Decoupling and Dilute Spin NMR in Solids. Chem Phys Lett. 1989;155:341–346.

Bielecki A, Kolbert A, de Groot HJM, Griffin RG. Frequency-switched Lee-Goldburg sequences in solids. Adv Magn Reson. 1990;14:111–124.

Bloch F, Siegert A. Magnetic resonance for nonrotating fields. Phys Rev. 1940;57:522–527.

Charmont P, Lesage A, Steuernagel S, Engelke F, Emsley L. Sample Restriction Using Magnetic Field Gradients in High-Resolution Solid-State NMR. J Magn Reson. 2000;145:334–339. doi: 10.1006/jmre.2000.2117. PubMed DOI

Charmont P, Sakellariou D, Emsley L. Sample restriction using radiofrequency field selective pulses in high-resolution solid-state NMR. J Magn Reson. 2002;154:136–141. doi: 10.1006/jmre.2001.2467. PubMed DOI

Emsley L. In: eMagRes. Harris RK, Wasylishen RE, editors. John Wiley & Sons, Ltd; Chichester, UK: 2007. Selective Pulses.

Ernst RR, Bodenhausen G, Wokaun A. Oxford University Press on Demand; 1990. Principles of Nuclear Magnetic Resonance in One and Two Dimensions.

Feng J, Reimer JA. Suppression of probe background signals via B PubMed DOI

Geen H, Freeman R. Band-Selective Radiofrequency Pulses. J Magn Reson. 1991;93:93–141. doi: 10.1016/0022-2364(91)90034-Q. DOI

Grzesiek S, Bax A. Audio-Frequency NMR in a Nutating Frame, Application to the Assignment of Phenylalanine Residues in Isotopically Enriched Proteins. J Am Chem Soc. 1995;117:6527–6531. doi: 10.1021/ja00129a016. DOI

Guenneugues M, Berthault P, Desvaux H. A method for determining B-1 field inhomogeneity. Are the biases assumed in heteronuclear relaxation experiments usually underestimated? J Magn Reson. 1999;136:118–126. doi: 10.1006/jmre.1998.1590. PubMed DOI

Gupta R, Hou G, Polenova T, Vega AJ. RF inhomogeneity and how it controls CPMAS. Solid State Nucl Magn Reson. 2015;72:17–26. doi: 10.1016/j.ssnmr.2015.09.005. PubMed DOI PMC

Hellwagner J, Grunwald L, Ochsner M, Zindel D, Meier BH, Ernst M. Origin of the residual line width under frequency-switched Lee–Goldburg decoupling in MAS solid-state NMR. Magn Reson. 2020;1:13–25. doi: 10.5194/mr-1-13-2020. PubMed DOI PMC

Khaneja N, Nielsen NC. Triple oscillating field technique for accurate distance measurements by solid-state NMR. J Chem Phys. 2008;128:015103. doi: 10.1063/1.2816140. PubMed DOI

Lindon JC, Beckonert OP, Holmes E, Nicholson JK. High-resolution magic angle spinning NMR spectroscopy: Application to biomedical studies. Prog NMR Spectr. 2009;55:79–100. doi: 10.1016/j.pnmrs.2008.11.004. DOI

Mithu VS, Tan KO, Madhu PK. Selective inversion of 1H resonances in solid-state nuclear magnetic resonance: Use of double-DANTE pulse sequence. J Magn Reson. 2013;237:11–16. doi: 10.1016/j.jmr.2013.09.010. PubMed DOI

Mote KR, Agarwal V, Madhu P. K. Five decades of homonuclear dipolar decoupling in solid-state NMR: Status and outlook. Prog NMR Spectr. 2016;97:1–39. doi: 10.1016/j.pnmrs.2016.08.001. PubMed DOI

Nishimura K, Fu R, Cross TA. The Effect of RF Inhomogeneity on Heteronuclear Dipolar Recoupling in Solid State NMR: Practical Performance of SFAM and REDOR. J Magn Reson. 2001;152:227–233. doi: 10.1006/jmre.2001.2410. DOI

Odedra S, Wimperis S. Imaging of the B1 distribution and background signal in a MAS NMR probehead using inhomogeneous B0 and B1 fields. J Magn Reson. 2013;231:95–99. doi: 10.1016/j.jmr.2013.04.002. PubMed DOI

Paruzzo FM, Walder BJ, Emsley L. Line narrowing in PubMed DOI

Paulson EK, Martin RW, Zilm KW. Cross polarization, radio frequency field homogeneity, and circuit balancing in high field solid state NMR probes. J Magn Reson. 2004;171:314–323. doi: 10.1016/j.jmr.2004.09.009. PubMed DOI

Smith SA, Levante TO, Meier BH, Ernst RR. Computer-Simulations in Magnetic-Resonance – an Object-Oriented Programming Approach. J Magn Reson Ser A. 1994;106:75–105.

States DJ, Haberkorn RA, Ruben DJ. A Two-Dimensional Nuclear Overhauser Experiment with Pure Absorption Phase in 4 Quadrants. J Magn Reson. 1982;48:286–292. doi: 10.1016/0022-2364(82)90279-7. DOI

Straasø LA, Bjerring M, Khaneja N, Nielsen NC. Multiple-oscillating-field techniques for accurate distance measurements by solid-state NMR. J Chem Phys. 2009;130:225103. doi: 10.1063/1.3147010. PubMed DOI

Tosner Z, Purea A, Struppe JO, Wegner S, Engelke F, Glaser SJ, Reif B. Radiofrequency fields in MAS solid state NMR probes. J Magn Reson. 2017;284:20–32. doi: 10.1016/j.jmr.2017.09.002. PubMed DOI

Tosner Z, Sarkar R, Becker-Baldus J, Glaubitz C, Wegner S, Engelke F, Glaser SJ, Reif B. Overcoming Volume Selectivity of Dipolar Recoupling in Biological Solid-State NMR Spectroscopy. Angew Chem Int Ed Engl. 2018;57:14514–14518. doi: 10.1002/anie.201805002. PubMed DOI

Vega AJ. Controlling the effects of pulse transients and RF inhomogeneity in phase-modulated multiple-pulse sequences for homonuclear decoupling in solid-state proton NMR. J Magn Reson. 2004;170:22–41. doi: 10.1016/j.jmr.2004.05.017. PubMed DOI

Wili N, Hintz H, Vanas A, Godt A, Jeschke G. Distance measurement between trityl radicals by pulse dressed electron paramagnetic resonance with phase modulation. Magn Reson. 2020;1:75–87. doi: 10.5194/mr-1-75-2020. PubMed DOI PMC

Effects of radial radio-frequency field inhomogeneity on MAS solid-state NMR experiments

Using nutation-frequency-selective pulses to reduce radio-frequency field inhomogeneity in solid-state NMR