Stereodynamics of 9,11-Diphenyl-10-azatetracyclo[6.3.0.0.4,110.5,9]undecanes. Highly Restricted Nitrogen Inversion and Isolated Phenyl Rotation. X-ray Crystallographic, Dynamic NMR, and Molecular Mechanics Studies

1996 ◽  
Vol 61 (13) ◽  
pp. 4319-4327 ◽  
Author(s):  
Gordon W. Gribble ◽  
Frank L. Switzer ◽  
John H. Bushweller ◽  
John G. Jewett ◽  
Jay H. Brown ◽  
...  
Keyword(s):  
Molecular Mechanics ◽  
Dynamic Nmr ◽  
X Ray ◽  
Nitrogen Inversion

Dynamic NMR and X-ray Studies of Chelated Lithium Phenolates. Tetramers with Pentacoordinate Lithium

1997 ◽  
Vol 62 (25) ◽  
pp. 8923-8927 ◽  
Author(s):  
Nikolai A. Khanjin ◽  
Fredric M. Menger
Keyword(s):  
Dynamic Nmr ◽  
X Ray

scholarly journals Structural Modeling of Glutathiones Containing Selenium and Tellurium

2016 ◽  
Vol 8 (1) ◽  
pp. 102
Author(s):  
Valter A. Nascimento ◽  
Petr Melnikov ◽  
André V. D. Lanoa ◽  
Anderson F. Silva ◽  
Lourdes Z. Z. Consolo
Keyword(s):  
Molecular Mechanics ◽  
Structural Characteristics ◽  
Structural Modeling ◽  
Structural Description ◽  
Ionic Radii ◽  
X Ray ◽  
Bond Angles ◽  
Bond Lengths ◽  
Available Information ◽  
Related Compounds

<p>The comparative structural modeling of reduced and oxidized glutathiones, as well as their derivatives containing selenium and tellurium in chalcogen sites (Ch = Se, Te) has provided detailed information about the bond lengths and bond angles, filling the gap in the structural characteristics of these tri-peptides. The investigation using the molecular mechanics technique with good approximation confirmed the available information on X-ray refinements for the related compounds. It was shown that Ch-H and Ch-C bond lengths grow in parallel with the increasing chalcogen ionic radii. Although the distances C-C, C-O, and C-N are very similar, the geometry of GChChG glutathiones is rich in conformers owing to the possibility of rotation about the bridge Ch-Ch. It is confirmed that the distances Ch-Ch are essentially independent of substituents in most of chalcogen compounds from elemental chalcogens to oxydized glutathiones. The standard program Hyperchem 7.5 has proved to be an appropriate tool for the structural description of less-common bioactive compositions when direct X-ray data are missing.</p>

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