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

Proton Distributions and Hydrogen Bonding in Crystalline and Glassy Hydrous Silicates and Related Inorganic Materials: Insights from High‐Resolution Solid‐State Nuclear Magnetic Resonance Spectroscopy

“…More recently reported 1 H DQ-1Q correlation spectra using proton homonuclear decoupling with the SAM3 and wSAMP3 schemes at a spinning speed of 35 kHz and a magnetic field of 9.4 T similarly revealed four 1 H peaks (although less resolved). 114 First principles calculation results of the 1 H chemical shifts 114 are also in agreement with the above assignment. The 1 H MAS NMR spectra acquired at a spinning speed of 40 kHz, and the total projection to the CRAMPS dimension of 2D 1 H CRAMPS (FSLG)-MAS NMR spectra acquired at a spinning speed of 15 kHz are shown in Fig.…”

Probing Intermolecular Crystal Packing in γ-Indomethacin by High-Resolution 1H Solid-State NMR Spectroscopy

“…[21][22][23] In particular, 1 H-1 H double-quantum spectroscopy is a powerful method for identifying proton-proton proximities up to~3.5 Å, be they intra-or intermolecular proximities. 24,25 By employing advances in homonuclear 1 H decoupling that deliver high-resolution 1 H spectra, 26,27 the 1 H-1 H DQ CRAMPS technique [28][29][30][31][32] has been applied to the potassium salt of penicillin characterised anhydrous polymorphs (that are labelled ,  and )  crystal structures are available for the  and  forms. 38,39 13 C CP MAS spectra have been reported for the crystalline polymorphs as well as amorphous forms of indomethacin, 13,[40][41][42] while a recent study has presented 1 H- 13 C and 1 H-1 H DQ twodimensional spectra for an indomethacin-polymer dispersion together with a 1 H-1 H DQ MAS spectrum of -indomethacin.…”

Solid state NMR study of hydrogen bonding, miscibility, and dynamics in multiphase polymer systems

“…Oxygen atoms are usually optimally located to monitor any hydrogen bonds, and due to its quadrupolar nature, it should be very sensitive to any changes of the strength of such interactions [110]. X-ray crystallographers have stated that the N-H…O-C hydrogen bond is a universal feature of amino acid aggregation in the [108]; b) Schematic system of four dipolar coupled (close in space) 1 H nuclei (H 1 …H 1 , H 1 …H 2 and H 2 …H 2 ). For identical chemical shifts, a unique on-diagonal correlation peak is observed.…”