(4R)-4-Hydroxy-1-nitroso-l-proline: synthesis, X-ray structure, ab initio and conformational calculations

Tetrahedron ◽  
2006 ◽  
Vol 62 (37) ◽  
pp. 8779-8786 ◽  
Author(s):  
Marina S. Fonari ◽  
Yurii M. Chumakov ◽  
Gheorghe G. Duca ◽  
Eduard V. Ganin ◽  
Arkadii A. Yavolovskii ◽  
...  
Keyword(s):  
Ab Initio ◽  
X Ray ◽  
Conformational Calculations

scholarly journals The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Alexandra Carvalho ◽  
Mariana C. F. Costa ◽  
Valeria S. Marangoni ◽  
Pei Rou Ng ◽  
Thi Le Hang Nguyen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ab Initio ◽  
State Of The Art ◽  
High Accuracy ◽  
Precise Determination ◽  
Photoemission Spectroscopy ◽  
Pristine Graphene ◽  
X Ray ◽  
Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

scholarly journals The influence of exocyclic lone pairs on the bonding and geometry of type A mesoionic rings

2021 ◽  
Author(s):  
Christopher Antony Ramsden ◽  
Wojciech Piotr Oziminski
Keyword(s):  
Ab Initio ◽  
Type A ◽  
Nbo Analysis ◽  
Ring Systems ◽  
X Ray ◽  
X Ray Crystallography ◽  
Bond Model ◽  
Lone Pairs ◽  
Mp2 Calculations ◽  
Good Agreement

AbstractBased on structures determined by X-ray crystallography, ab initio MP2 calculations on type A mesoionic rings give geometries in good agreement with observed values. A study of four mesoionic ring systems, each with exocyclic oxygen, nitrogen or carbon groups, shows that the presence and configuration of exocyclic lone pairs significantly influences the geometry and configurational preference. Using a localised bond model and NBO analysis, these effects are rationalised in terms of an anomeric interaction of lone pairs with the antibonding orbitals of adjacent σ bonds. In agreement with experiment, similar effects are calculated for pyran-2-imines.

Ab initio calculations of X-ray emission from C60

1994 ◽  
Vol 227 (1-2) ◽  
pp. 98-102 ◽  
Author(s):  
J.-H. Guo ◽  
Y. Luo ◽  
O. Vahtras ◽  
P. Skytt ◽  
N. Wassdahl ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document