Double-Quantum Filtered MAS NMR in the Presence of Chemical Shielding Anisotropies and Direct Dipolar and JCouplings

Efficiency of the Refocused 31P−29Si MAS-J-INEPT NMR Experiment for the Characterization of Silicophosphate Crystalline Phases and Amorphous Gels

“…The second category includes J -mediated experiments, where J stands for the heteronuclear or homonuclear isotropic scalar coupling. In the early 1990's, such NMR sequences were implemented by Fyfe and co-workers and Eckert and co-workers . In the late 1990's, Emsley and co-workers showed that the INADEQUATE (incredible natural abundance double quantum transfer experiment) and the HMQC (heteronuclear multiple quantum coherence) sequences could be safely transposed in solid-state NMR for the study of organic and bio-organic derivatives.…”

Double-Quantum-Filtered Rotational-Resonance MAS NMR in the Presence of Large Chemical Shielding Anisotropies

“…Both pulse sequences considerably expand the practical range of spin systems on which R 2 experiments may be successfully carried out in terms of lineshape simulations but where conventional R 2 lineshapes cannot be used. A general area of application where this is important is, for instance, MAS NMR applications on inorganic solids with spin-1/2 isotopes in low natural abundance (40).…”

Covalent Bonds in α‐SnF2 Monitored by J‐Couplings in Solid‐State NMR Spectra

“…Wiley-VCH ZAAC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 The shortest distances for heteronuclear and homonuclear pairs of nuclei reported for the X-ray structure [1] As a third contribution to line broadening, J-couplings have to be taken into account for 119 Sn, since it has been documented previously [9][10][11][12][13][14][15][16][17][18][19][20][21] that they may also be of the order of kHz. In fact, the J-couplings for 119 Sn can be so large that it has been possible to determine the anisotropy of this interaction in some organo-tin compounds [14] by using off-magic angle spinning.…”

“…Unlike dipolar couplings, which act through space, J-couplings are mediated by covalent bonds, and are difficult to observe in solid-state NMR, because they are usually much smaller than dipolar couplings [6][7][8]. For 119 Sn however, J-couplings tend to be comparatively large (in the range of kHz), and have been reported before in the literature for a variety of compounds [9][10][11][12][13][14][15][16][17][18][19][20][21]. The existence of J-couplings in α-SnF 2 shown here is further evidence for the existence of covalent Sn-F bonds in tin(II) fluoride.…”