Precision Measurement of the Quadrupole Coupling and Chemical Shift Tensors of the Deuterons in α-Calcium Formate

X-ray, 31P CP/MAS, and Single-crystal NMR Studies, and 31P DFT GIAO Calculations of Inclusion Complexes of Bis[6-O,6-O′-(1,2:3,4-Diisopropylidene-α-D-galactopyranosyl)thiophosphoryl] Disulfide: The Importance of CbH⋅⋅⋅SdP Contacts in the Solid State

“…[21] Apart from shift data as in Figure 5, SUPERFIT needs as input (i) the orientation of the rotation axis R of each pattern specified by, for example, its polar angles W R and f R in the SOS and, ii) a reference angle f R for which rotation angle f the applied field B 0 is parallel to a specified reference direction in the plane perpendicular to the rotation axis. By inspection of the x c and z c patterns in Figure 5 we can safely conclude that the crossing of the two traces at the common value of about d 160 must correspond to B 0 , approximately parallel to b.…”

2H chemical shift anisotropies from high-field 2H MAS NMR spectroscopy

“…This is illustrated by a determination of the 2 H CSA and quadrupole coupling parameters for KD 2 PO 4 , ND 4 D 2 PO 4 , KDCO 3 , KDSO 4 , a-(COOD) 2 , a-(COOD) 2 Á 2D 2 O, and boehmite (AlOOD). With the exception of boehmite, 1 [32], a-glycine [33], and for the amide and carboxyl hydrogens of N-acetyl-D D ,L L -valine [34] in all cases employing single-crystal 2 H NMR spectroscopy.…”

The proton nuclear magnetic shielding tensors in biphenyl: Experiment and theory

“…Actually, proton shielding tensors are hardly anymore a reason to perform line-narrowing multiple pulse experiments. There are adequate, even superior, alternatives: first, single crystal deuteron NMR in very high applied fields [16] and, second, calculation by the quantum chemical method explored and tested against experiment here, perhaps supplemented by the old susceptibility method. After elimination of systematic errors, these theoretical methods allow with reasonable effort to access proton shielding tensors on a sub-ppm accuracy level not only in the isolated molecule but also in the natural crystal environment.…”

“…The reason is that intermolecular shielding contributions cause the measurable r-tensor to deviate significantly from that in the isolated molecule [6,15,16]. Note that, in general, the problem with intermolecular shielding contributions is particularly acute for protons because, first, protons usually sit, as they do in biphenyl, at the periphery of the molecule and are thus exposed to stronger fields arising from electron motions in neighboring molecules than nuclei located further inside such as carbons.…”