Enhanced resolution in proton solid-state NMR with very-fast MAS experiments

1H line width dependence on MAS speed in solid state NMR – Comparison of experiment and simulation

“…For other systems where deuterated derivatives need to be synthesized chemically, this route is less common due to a more resource intensive nature of the approach. On the other hand, CRAMPS methods achieved a remarkable feat of efficient averaging of the 1 H-1 H dipolar couplings even under moderate spinning frequencies [16][17][18][19][20][21][22][23][24][25]. Thanks to this, investigations on uniformly protonated compounds have become increasingly popular in the recent years [18,21,[26][27][28][29][30][31][32][33][34].…”

1H–1H double-quantum CRAMPS NMR at very-fast MAS (νR=35kHz): A resolution enhancement method to probe 1H–1H proximities in solids

“…SAM is a smooth version of CN N=2 n rotor-synchronized pulse sequence, which uses a Zero (instead of 360°) rotation basic element that corresponds to a z-rotation for chemical shift and does not cancel it. In our case, we have employed the SAM 3 [11] and wSAM 3 [12] decoupling versions during t 1 and t 2 evolutions, respectively. SAM 3 corresponds to a continuous version of the C6 3 1 symmetry sequence using three rf cosine modulation periods every rotor period s R .…”

Robust and efficient spin-locked symmetry-based double-quantum homonuclear dipolar recoupling for probing 1H–1H proximity in the solid-state

“…The SPIP spectrum is similar to that published by Madhu and co-workers [9], who used the C9 4 1 DQ-SQ sequence, but it reveals more correlations (13 instead of 8) despite the fact that a PMLG decoupling method was used along F1 and F2 in ref [9], which increased the S/N ratio. Obviously, our spectra would have been quite improved by also using an homonuclear decoupling along F1 and F2 [32][33][34].…”