Single-crystal 207Pb-NMR of wulfenite, PbMoO4, aided by simultaneous measurement of phosgenite, Pb2Cl2CO3

Single-Crystal NMR Spectroscopy

“…Although 207 Pb NMR has been extensively used to study different lead-containing solids [108], to our knowledge there have only been few 207 Pb SC NMR studies in the past [109,110], until this has recently been brought up by Bräuniger and co-workers [48,[111][112][113]. In their combined 51 V and 207 Pb SC NMR study of Pb 5 (VO 4 ) 3 Cl [48], they observed the expected 207 Pb resonances originating from three magnetically inequivalent lead atoms in pos 6h and two in pos 4f.…”

Determination of the 31P and 207Pb Chemical Shift Tensors in Pyromorphite, Pb5(PO4)3Cl, by Single‐Crystal NMR Measurements and DFT Calculations

“…The two 207 Pb at Wyckoff position 4f are related by the mirror plane parallel to ab at 1/4c, which can be realized by the transformation S -1 • δ LAB • S, using a reflection matrix S. A more detailed exposition of these symmetry transformations, including the definitions of the K and S matrices, can be found in the literature. [1] The two harmonics of the 207 Pb at 4f (which are never resolved for our rotation axis) do however not deliver a sufficient number of independent parameters to determine the full tensor. Therefore, we had to include the value of the isotropic chemical shift, δ iso , derived from the MAS NMR spectroscopic experiments described below, as an additional parameter.…”

“…In an identical procedure to that employed for vanadinite, [1] a multiparameter fit for the chemical shift tensors of 31 P and 207 Pb at 6h, and 207 Pb at 4f was implemented (see Experimental Section for details). Two free parameters remained to also fit the initial orientation of the crystallographic c axis, expressed by the angles θ and φ in spherical coordinates.…”

“…We have recently conducted a study of vanadinite single crystals using Nuclear Magnetic Resonance (NMR) spectroscopy. [1] Since NMR spectroscopy probes the local surrounding of the observed nuclei, it is capable of providing information about structure and dynamics, which is complementary to that obtained from X-ray diffraction methods. [2][3][4][5] In solid-state NMR spectroscopy, information about the electronic distribution is encapsulated in the orientation dependence of the chemical shift (and for spin I Ͼ 1/2, the quadrupolar coupling), with the dependence customarily expressed using second-rank tensor notation.…”

“…NMR spectroscopy of single crystals using only one rotation axis. Since this method has been described extensively in a recent publication, [1] only a brief outline will be given here. Friedrichssegen near Bad Ems, Germany.…”