15N NMR Chemical Shift Tensors of Substituted Hexaazaisowurtzitanes:  The Intermediates in the Synthesis of CL-20†

2004 ◽  
Vol 108 (14) ◽  
pp. 2638-2644 ◽  
Author(s):  
Jacalyn S. Clawson ◽  
Karen L. Anderson ◽  
Ronald J. Pugmire ◽  
David M. Grant
Keyword(s):  
Chemical Shift ◽  
15N Nmr ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

Measurement and calculation of 13C and 15N NMR chemical-shift tensors of a push–pull ethylene

2009 ◽  
Vol 87 (4) ◽  
pp. 563-570 ◽  
Author(s):  
Saeed K. Amini ◽  
Mohsen Tafazzoli ◽  
Hilary A. Jenkins ◽  
Gillian R. Goward ◽  
Alex D. Bain
Keyword(s):  
Double Bond ◽  
Chemical Shift ◽  
Charge Density ◽  
Density Functional ◽  
The Other ◽  
15N Nmr ◽  
Nmr Chemical Shift ◽  
Strong Electron ◽  
Chemical Shift Tensors ◽  
Donor And Acceptor

Methyl 3-dimethylamino-2-cyanocrotonate (MDACC) has a remarkably weak carbon–carbon double bond. It has strong electron-withdrawing groups on one end and electron-donating groups on the other: a so-called push–pull ethylene. To investigate this unusual electronic structure, we have determined the crystal structure and measured both the 13C and 15N NMR chemical-shift tensors. These measurements are supplemented by shielding-tensor calculations done with density functional methods. The large difference (approximately 100 ppm) between isotropic chemical shifts of the two alkenyl carbons reflects a large charge release from the electron-donating side of C=C double bond to the electron-withdrawing groups. Comparison of the calculated orientations of the principal components of the alkenyl carbons obtained from ab initio calculations shows that the primary changes in charge density occur in the molecular plane. On the other hand, smaller charge density changes above and below the plane of the C=C double bond establish the conjugation of donor and acceptor groups with π* and π molecular orbitals of the central double bond, respectively, which lowers the barrier to rotation about this bond.

scholarly journals Modeling Small Structural and Environmental Differences in Solids with 15 N NMR Chemical Shift Tensors

ChemPhysChem ◽  
2021 ◽  
Author(s):  
Luther Wang ◽  
Alexander B. Elliott ◽  
Sean D. Moore ◽  
Gregory J. O. Beran ◽  
Joshua D. Hartman ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

Local-structure effects on 31P NMR chemical shift tensors in solid state

2019 ◽  
Vol 150 (14) ◽  
pp. 144706 ◽  
Author(s):  
Ivan Yu. Chernyshov ◽  
Mikhail V. Vener ◽  
Ilya G. Shenderovich
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Local Structure ◽  
31P Nmr ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

119Sn NMR chemical shift tensors in anhydrous and hydrated Si8O20(SnMe3)8 crystals

2008 ◽  
Vol 46 (7) ◽  
pp. 690-692 ◽  
Author(s):  
Jian Jiao ◽  
Ming-Yung Lee ◽  
Craig E. Barnes ◽  
Edward W. Hagaman
Keyword(s):  
Chemical Shift ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors ◽  
119Sn Nmr

Interpretation of Crystal Effects on NMR Chemical Shift Tensors: Electron and Shielding Deformation Densities

2013 ◽  
Vol 117 (2) ◽  
pp. 497-503 ◽  
Author(s):  
Martin Babinský ◽  
Kateřina Bouzková ◽  
Matej Pipíška ◽  
Lucie Novosadová ◽  
Radek Marek
Keyword(s):  
Chemical Shift ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

Hydrogen Bonding Effects on the13C NMR Chemical Shift Tensors of Some Amino Acids in the Solid State

1997 ◽  
Vol 35 (9) ◽  
pp. 606-608 ◽  
Author(s):  
Guang Zheng ◽  
Liming Wang ◽  
Jianzhi Hu ◽  
Xiaodong Zhang ◽  
Lianfang Shen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Chemical Shift ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

1H, 13C and 15N NMR chemical shift assignments of A. thaliana RCD1 RST

2017 ◽  
Vol 11 (2) ◽  
pp. 207-210 ◽  
Author(s):  
Helena Tossavainen ◽  
Maarit Hellman ◽  
Julia P. Vainonen ◽  
Jaakko Kangasjärvi ◽  
Perttu Permi
Keyword(s):  
Chemical Shift ◽  
15N Nmr ◽  
Chemical Shift Assignments ◽  
Nmr Chemical Shift ◽  
Nmr Chemical Shift Assignments
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