NMR interaction tensors of 51V and 207Pb in vanadinite, Pb5(VO4)3Cl, determined from DFT calculations and single-crystal NMR measurements, using only one general rotation axis

2018 ◽  
Vol 89 ◽  
pp. 11-20 ◽  
Author(s):  
Otto E.O. Zeman ◽  
Constantin Hoch ◽  
Rupert Hochleitner ◽  
Thomas Bräuniger
2007 ◽  
Vol 129 (14) ◽  
pp. 4240-4252 ◽  
Author(s):  
Raanan Carmieli ◽  
Todd M. Larsen ◽  
George H. Reed ◽  
Samir Zein ◽  
Frank Neese ◽  
...  

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.


Author(s):  
Zhi song Yang ◽  
Xiangzhi Cai ◽  
Junjiang Chen ◽  
Yuan Shi ◽  
Pengyue Huang ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 302
Author(s):  
Otto E. O. Zeman ◽  
Viktoria Kainz ◽  
Thomas Bräuniger

The electronic surroundings of phosphorus and lithium atoms in the ionic conductor lithium dihydrogen phosphate (LDP) have been studied by single-crystal nuclear magnetic resonance (NMR) spectroscopy at room temperature. From orientation-dependent NMR spectra of a large homegrown LDP single crystal, the full 31P chemical shift (CS) and 7Li quadrupole coupling (QC) tensor was determined, using a global fit over three rotation patterns. The resulting CS tensor is characterized by its three eigenvalues: δ 11 P A S = ( 67.0 ± 0.6 ) ppm, δ 22 P A S = ( 13.9 ± 1.5 ) ppm, and δ 33 P A S = ( − 78.7 ± 0.9 ) ppm. All eigenvalues have also been verified by magic-angle spinning NMR on a polycrystalline sample, using Herzfeld–Berger analysis of the rotational side band pattern. The resulting 7Li QC tensor is characterized by its quadrupolar coupling constant χ = Q 33 P A S = ( − 71 ± 1 ) kHz and the two eigenvalues Q 11 P A S = ( 22.3 ± 0.9 ) kHz, and Q 22 P A S = ( 48.4 ± 0.8 ) kHz. The initially unknown orientation of the mounted crystal, expressed by the orientation of the rotation axis in the orthorhombic crystal frame, was included in the global data fit as well, thus obtaining it from NMR data only.


2020 ◽  
Vol 73 (6) ◽  
pp. 579
Author(s):  
Hamzé Almallah ◽  
Eric Brenner ◽  
Dominique Matt ◽  
Mohamad Jahjah ◽  
Akram Hijazi ◽  
...  

Two imidazolylidene (Im) complexes of the general formula trans-[PdX2(Im)(pyridine)] (X=Cl (2), Br (3)), in which the N-heterocyclic carbene ligand has one of its nitrogen atoms substituted by a bulky 9-propyl-9-fluorenyl group (PrF), have been prepared and fully characterised by spectroscopic methods and single-crystal X-ray structure analyses. In the solid state, the Im ring plane and the coordination plane of each complex are nearly orthogonal, thereby minimising the steric interactions between the N-substituents and the halide atoms. In both structures two methylenic C–H bonds sit near the dz2 axis point to the palladium atom, resulting in CH⋯Pd separations of 2.58/2.95Å in 2 and 2.74/2.74Å in 3. NMR measurements and DFT calculations indicate that these methylene groups are involved in anagostic CH⋯M interactions but not in significant H⋯X bonding.


2019 ◽  
Vol 7 (22) ◽  
pp. 6767-6778 ◽  
Author(s):  
Man Wang ◽  
Caiqi Cheng ◽  
Chunbo Li ◽  
Dehua Wu ◽  
Jintong Song ◽  
...  

Multidentate and environmentally sensitive dyes show turn-on, ratiometric, and thermochromic fluorescence.


2014 ◽  
Vol 1067 ◽  
pp. 210-215 ◽  
Author(s):  
Raj Pal Sharma ◽  
Anju Saini ◽  
Santosh Kumar ◽  
Paloth Venugopalan ◽  
Valeria Ferretti

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ataf A. Altaf ◽  
Adnan Shahzad ◽  
Zarif Gul ◽  
Sher A. Khan ◽  
Amin Badshah ◽  
...  

1,3-Diisobutyl thiourea was synthesized and characterized by single crystal X-ray diffraction. It gives a monoclinic (α=γ= 90 andβ  ≠90) structure with the space group P21/c. The unit cell dimensions area= 11.5131 (4) Å,b= 9.2355 (3) Å,c= 11.3093 (5) Å,α= 90°,β= 99.569° (2),γ= 90°,V= 1185.78 (8) Å3, andZ= 4. The crystal packing is stabilized by intermolecular (N–H⋯S) hydrogen bonding in the molecules. The optimized geometry and Mullikan's charges of the said molecule calculated with the help of DFT using B3LYP-6-311G model support the crystal structure.


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