scholarly journals Characterisation of contact twinning for cerussite, $$\hbox {PbCO}_3$$, by single-crystal NMR spectroscopy

2021 ◽  
Vol 48 (11) ◽  
Author(s):  
Otto E. O. Zeman ◽  
Jennifer Steinadler ◽  
Rupert Hochleitner ◽  
Thomas Bräuniger
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Single Crystal ◽  
Room Temperature ◽  
Relative Orientation ◽  
Chemical Shift Tensor ◽  
Global Fit

AbstractCerussite, $$\hbox {PbCO}_3$$ PbCO 3 , like all members of the aragonite group, shows a tendency to form twins, due to high pseudo-symmetry within the crystal structure. We here demonstrate that the twin law of a cerussite contact twin may be established using only $$^{207}$$ 207 Pb-NMR spectroscopy. This is achieved by a global fit of several sets of orientation-dependent spectra acquired from the twin specimen, allowing to determine the relative orientation of the twin domains. Also, the full $$^{207}$$ 207 Pb chemical shift tensor in cerussite at room temperature is determined from these data, with the eigenvalues being $$\delta _{11} = (-2315\pm 1)$$ δ 11 = ( - 2315 ± 1 )  ppm, $$\delta _{22} = (-2492 \pm 3)$$ δ 22 = ( - 2492 ± 3 )  ppm, and $$\delta _{33} = (-3071 \pm 3)$$ δ 33 = ( - 3071 ± 3 )  ppm.

scholarly journals The Chemical Shift of the 29Si Nuclear Magnetic Resonance in a Synthetic Single Crystal of Mg2SiO4

1985 ◽  
Vol 40 (2) ◽  
pp. 126-130 ◽  
Author(s):  
N. Weiden ◽  
H. Rager
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Single Crystal ◽  
Angular Dependence ◽  
Room Temperature ◽  
Bond Distance ◽  
Chemical Shift Tensor ◽  
The Individual ◽  
Nuclear Magnetic

The angular dependence of the chemical shift of the 29Si nuclear magnetic resonance has been measured in a synthetic single crystal of Mg2SiO4 (space group Pbnm, Z = 4). The measurements were performed at room temperature at a frequency of 39.758 MHz using the FT-NMR technique. The eigenvalues of the shift tensor with respect to 29Si in TMS are δx = - 38.8 ppm, δv = -55.3 ppm and δz = - 95.4 ppm, with the eigenvector y parallel to c and the eigenvector z forming an angle of 7.5° with a. The results show clearly the influence of the individual S i - O bonds on the chemical shift tensor. The chemical shift along the S i -O bond depends in good approximation exponentially on the S i - O bond distance.

The129Xe Chemical Shift Tensor in a Silicalite Single Crystal from Hyperpolarized129Xe NMR Spectroscopy

2001 ◽  
Vol 123 (42) ◽  
pp. 10399-10400 ◽  
Author(s):  
Victor V. Terskikh ◽  
Igor L. Moudrakovski ◽  
Hongbin Du ◽  
Christopher I. Ratcliffe ◽  
John A. Ripmeester
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Single Crystal ◽  
Chemical Shift Tensor

207Pb and 205Tl NMR on Perovskite Type Crystals APbX3 (A = Cs, Tl, X = Br, I)

1987 ◽  
Vol 42 (11) ◽  
pp. 1313-1320 ◽  
Author(s):  
Surendra Sharma ◽  
Norbert Weiden ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Chemical Shift ◽  
Single Crystals ◽  
Room Temperature ◽  
Saturated Aqueous Solution ◽  
Chemical Shift Tensor ◽  
Chemical Shift Tensors ◽  
Perovskite Type

By 205Tl and 207Pb NM R the chemical shift in polycrystalline samples of binary halides AX, BX2 and ternary halides ABX3 (A = Cs, Tl; B = Pb; X = Br, I) was studied at room temperature. The chemical shift tensors δ ( 205Tl) and δ (207Pb) were determined in magnitude and orientation on single crystals of the orthorhombic TlPbI3. The components of the δ(205Tl) tensor are δx (205Tl) || a = 611ppm; δy (205Tl) || b = 680 ppm; δZ(205Tl) || c = 1329 ppm; δiso(205Tl) = 873.3 ppm (with respect to 3.4 molar aqueous solution of TlOOCCH3). The chemical shift tensor of 207Pb in TlPbI3 shows two orientations. One of them is: δx (207Pb) = 3760 ppm, inclined 30° from b towards c, δy(207Pb) || a = 3485 ppm, δz(207Pb) = 2639 ppm inclined 120° from b towards c. δiso(207Pb) = 3295 ppm (with respect to saturated aqueous solution of Pb(NO3)2). The results are discussed with respect to the crystal structure and a model to explain orientation and anisotropy of the tensors δ(205Tl) and δ(207Pb) in TlPbI3 is proposed.In the system CsPbBr3-x Ix δ(207Pb) was studied on polycrystalline samples. The chemical shift increases with increasing x and negative excess shift is observed.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.

Structural Systematics of Rare Earth Complexes. VII. Crystal Structure of Bis(2,2'/6',2␛-Terpyridinium) Octaaquaterbium(III) Heptachloride Hydrate

1994 ◽  
Vol 47 (2) ◽  
pp. 391 ◽  
Author(s):  
CJ Kepert ◽  
BW Skeleton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Single Crystal ◽  
Structural Characterization ◽  
Title Compound ◽  
Room Temperature ◽  
Chloride Ions ◽  
Full Matrix ◽  
X Ray

The room-temperature single-crystal X-ray structural characterization of the title compound (tpyH2)2[Tb(OH2)8]Cl7.~2⅓H2O is recorded. Crystals are triclinic, Pī , a 17.063(5), b 16.243(3), c 7.878(3) Ǻ, α 84.78(2), β 84.39(3), γ 87.81(2)°, Z = 2 formula units; 3167 'observed' diffractometer reflections were refined by full-matrix least-squares procedures to a residual of 0.057. Notable features of interest of the compound are the 'chelation' of chloride ions by the terpyridinium cations , and the existence of a free [Tb(OH2)8]2+ cation in the presence of an abundance of chloride ions.

Evolution of crystal structure of dual layered molecular conductor (ET)4ZnBr4(C6H4Cl2) with temperature

CrystEngComm ◽  
2021 ◽  
Author(s):  
Gennady V. Shilov ◽  
Elena I. Zhilyaeva ◽  
Sergey M. Aldoshin ◽  
Alexandra M Flakina ◽  
Rustem B. Lyubovskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Resistivity ◽  
Single Crystal ◽  
Room Temperature ◽  
Organic Conductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Molecular Conductor ◽  
Abrupt Changes

Electrical resistivity measurements of a dual layered organic conductor (ET)4ZnBr4(1,2-C6H4Cl2) above room temperature show abrupt changes in resistivity at 320 K. Single-crystal X-ray diffraction studies in the 100-350 K range...

Intermolecular Interactions of Xe Atoms Confined in One-dimensional Nanochannels of Tris(o-phenylenedioxy)cyclotriphosphazene as Studied by High-pressure 129Xe NMR

2003 ◽  
Vol 58 (12) ◽  
pp. 727-734 ◽  
Author(s):  
Hirokazu Kobayashi ◽  
Takahiro Ueda ◽  
Keisuke Miyakubo ◽  
Taro Eguchi
Keyword(s):  
High Pressure ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Pressure Dependence ◽  
Average Distance ◽  
Chemical Shift Tensor ◽  
Axially Symmetric ◽  
One Dimensional ◽  
129Xe Nmr ◽  
The One

The pressure dependence of the 129Xe chemical shift tensor confined in the Tris(o-phenylenedioxy) cyclotriphosphazene (TPP) nanochannel was investigated by high-pressure 129Xe NMR spectroscopy. The observed 129Xe spectrum in the one-dimensional TPP nanochannel (0.45 nm in diameter) exhibits a powder pattern broadened by an axially symmetric chemical shift tensor. As the pressure increases from 0.02 to 7.0 MPa, a deshielding of 90 ppm is observed for the perpendicularcomponent of the chemical shift tensor δ⊥, whereas a deshielding of about 30 ppm is observed for the parallel one, δ‖. This suggests that the components of the chemical shift tensor, δ‖ and δ⊥, are mainly dominated by the Xe-wall and Xe-Xe interaction, respectively. Furthermore, the effect of helium, which is present along with xenon gas, on the 129Xe chemical shift is examined in detail. The average distance between the Xe atoms in the nanochannel is estimated to be 0.54 nm. This was found by using δ⊥ at the saturated pressure of xenon, and comparing the increment of the chemicalshift value in δ⊥ to that of a β -phenol/Xe compound.

scholarly journals Synthesis and Single Crystal X-Ray Structure of Bis[4-oxo-3- (2-ethoxycarbonylphenyl)-3,4-dihydroquinazolin-2-yl]disulfide

2009 ◽  
Vol 64 (9) ◽  
pp. 1065-1069 ◽  
Author(s):  
Mehdi Rimaz ◽  
Jabbar Khalafy ◽  
Khadijeh Tavana ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Elemental Analysis ◽  
Structure Determination ◽  
Room Temperature ◽  
Sodium Ethoxide ◽  
Reaction Conditions ◽  
X Ray ◽  
Ethyl Nitroacetate ◽  
C Nmr

Diethyl 2,2´-thiocarbonyl-bis(azanediyl)dibenzoate was synthesized from the reaction of ethyl anthranilate with thiophosgene. Its treatment with sodium ethoxide in ethanol at room temperature gave ethyl 2-(4-oxo-2-thioxo-1,2-dihydroquinazolin-3(4H)-yl) benzoate, whereas in the presence of ethyl nitroacetate and under the same reaction conditions, the corresponding bis(quinazolin)disulfide was formed. Its structure was confirmed by IR, 1H and 13C NMR spectroscopy elemental analysis and single crystal X-ray structure determination.

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