ChemInform Abstract: Crystal and Electronic Structures of ScAuGe, CeAuGe, and LuAuGe: a Transition from Two- to Three-Dimensional (AuGe) Polyanions.

ChemInform ◽  
2010 ◽  
Vol 27 (31) ◽  
pp. no-no
Author(s):  
R. POETTGEN ◽  
H. BORRMANN ◽  
C. FELSER ◽  
O. JEPSEN ◽  
R. HENN ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Three Dimensional

scholarly journals Three-dimensional electronic structures and the metal-insulator transition in Ruddlesden-Popper iridates

2016 ◽  
Vol 94 (11) ◽  
Author(s):  
A. Yamasaki ◽  
H. Fujiwara ◽  
S. Tachibana ◽  
D. Iwasaki ◽  
Y. Higashino ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Three Dimensional ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator

Six closely related 4,6-disubstituted 2-amino-5-formylpyrimidines: different ring conformations, polarized electronic structures, and hydrogen-bonded assembly in zero, one, two and three dimensions

2013 ◽  
Vol 69 (2) ◽  
pp. 162-171
Author(s):  
Lina M. Acosta ◽  
Andrés F. Yepes ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Electronic Structures ◽  
Three Dimensional ◽  
Pyrimidine Ring ◽  
Three Dimensions ◽  
Boat Conformation ◽  
A Chain ◽  
Dimeric Aggregates ◽  
Ring Conformations ◽  
Methyl Phenyl

In each of ethylN-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinate, C16H19N5O3, (I),N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}glycinamide, C14H16N6O2, (II), and ethyl 3-amino-N-{2-amino-5-formyl-6-[methyl(phenyl)amino]pyrimidin-4-yl}propionate, C17H21N5O3, (III), the pyrimidine ring is effectively planar, but in each of methylN-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}glycinate, C16H19N5O3, (IV), ethyl 3-amino-N-{2-amino-6-[benzyl(methyl)amino]-5-formylpyrimidin-4-yl}propionate, C18H23N5O3, (V), and ethyl 3-amino-N-[2-amino-5-formyl-6-(piperidin-4-yl)pyrimidin-4-yl]propionate, C15H23N5O3, (VI), the pyrimidine ring is folded into a boat conformation. The bond lengths in each of (I)–(VI) provide evidence for significant polarization of the electronic structure. The molecules of (I) are linked by paired N—H...N hydrogen bonds to form isolated dimeric aggregates, and those of (III) are linked by a combination of N—H...N and N—H...O hydrogen bonds into a chain of edge-fused rings. In the structure of (IV), molecules are linked into sheets by means of two hydrogen bonds, both of N—H...O type, in the structure of (V) by three hydrogen bonds, two of N—H...N type and one of C—H...O type, and in the structure of (VI) by four hydrogen bonds, all of N—H...O type. Molecules of (II) are linked into a three-dimensional framework structure by a combination of three N—H...O hydrogen bonds and one C—H...O hydrogen bond.

Symmetrically 4,6-disubstituted 2-aminopyrimidines and 2-amino-5-nitrosopyrimidines: interplay of molecular, molecular–electronic and supramolecular structures

2004 ◽  
Vol 60 (1) ◽  
pp. 76-89 ◽  
Author(s):  
Antonio Quesada ◽  
Antonio Marchal ◽  
Manuel Melguizo ◽  
John N. Low ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Electronic Structures ◽  
Three Dimensional ◽  
Supramolecular Structures ◽  
Nitroso Compounds ◽  
Stacking Interactions ◽  
Two Dimensional ◽  
Molecular Electronic ◽  
One Dimensional

The structures of six symmetrically 4,6-disubstituted 2-aminopyrimidines, four of them containing a 5-nitroso substituent, have been determined. The nitroso compounds, in particular, exhibit polarized molecular–electronic structures leading to extensive charge-assisted hydrogen bonding. The intermolecular interactions observed include hard hydrogen bonds of N—H...N and N—H...O types together with O—H...O and O—H...N types in 2-amino-4,6-bis(2-hydroxyethylamino)-5-nitrosopyrimidine; soft hydrogen bonds of the C—H...O type in both 2-amino-4,6-bis(morpholino)-5-nitrosopyrimidine (3) and 2-amino-4,6-bis(benzylamino)-5-nitrosopyrimidine (4), and of the C—H...π(arene) type in both 2-amino-4,6-bis(piperidino)pyrimidine (1) and 2-amino-5-nitroso-4,6-bis(3-pyridylmethoxy)pyrimidine (5); and aromatic π...π stacking interactions in 2-amino-5-nitroso-4,6-bis(3-pyridylmethoxy)pyrimidine. The supramolecular structures formed by the hard hydrogen bonds are finite, zero-dimensional in (1), one-dimensional in 2-amino-4,6-bis(3-pyridylmethoxy)pyrimidine (2), two-dimensional in both (3) and (4), and three-dimensional in both (5) and 2-amino-4,6-bis(2-hydroxyethylamino)-5-nitrosopyrimidine.

AB INITIO CALCULATIONS OF THE ELECTRONIC STRUCTURES AND BIOLOGICAL FUNCTIONS OF PROTEIN MOLECULES

2002 ◽  
Vol 16 (30) ◽  
pp. 1151-1162 ◽  
Author(s):  
HAOPING ZHENG
Keyword(s):  
Ab Initio ◽  
Trypsin Inhibitor ◽  
Electronic Structures ◽  
Biological Function ◽  
Three Dimensional ◽  
Protein Molecule ◽  
Computational Effort ◽  
Biological Functions ◽  
Protein Molecules

The self-consistent cluster-embedding (SCCE) calculation method reduces the computational effort from M3 to about M1 (M is the number of atoms in the system) with precise calculations. Thus the ab initio, all-electron calculation of the electronic structure and biological function of protein molecule has become a reality, which will promote new proteomics considerably. The calculated results of two real protein molecules, the trypsin inhibitor from the seeds of squash Cucurbita maxima (CMTI-I, 436 atoms) and the ascaris trypsin inhibitor (912 atoms, two three-dimensional structures), will be presented in this paper. The reactive sites of the inhibitors are determined and explained. The accuracy of structure determination of the inhibitors are tested theoretically.

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