scholarly journals Electronic and Steric Control of n→π* Interactions: Stabilization of the α‐Helix Conformation without a Hydrogen Bond

ChemBioChem ◽  
2019 ◽  
Vol 20 (7) ◽  
pp. 963-967 ◽  
Author(s):  
Nicole A. Wenzell ◽  
Himal K. Ganguly ◽  
Anil K. Pandey ◽  
Megh R. Bhatt ◽  
Glenn P. A. Yap ◽  
...  
2014 ◽  
Vol 13 (3) ◽  
pp. 541 ◽  
Author(s):  
Elena V. Eremeeva ◽  
Ludmila P. Burakova ◽  
Vasilisa V. Krasitskaya ◽  
Alexander N. Kudryavtsev ◽  
Osamu Shimomura ◽  
...  

2015 ◽  
Vol 71 (9) ◽  
pp. o636-o636
Author(s):  
Nadiah Ameram ◽  
Farook Adam

In the title compound, C16H17N3OS, a benzoyl thiourea derivative, the planes of the pyridine and benzene rings are inclined to one another by 66.54 (9)°. There is an intramolecular N—H...O hydrogen bond present forming anS(6) ring motif. In the crystal, molecules are linkedviapairs of N—H...N hydrogen bonds, forming inversion dimers, which are reinforced by pairs of C—H...S hydrogen bonds. The dimers are linkedviaC—H...π interactions, forming ribbons along [010].


2012 ◽  
Vol 68 (4) ◽  
pp. o1083-o1083 ◽  
Author(s):  
Ali Ourari ◽  
Djouhra Aggoun ◽  
Sofiane Bouacida

In the title compound, C15H17NO3, the mean planes of the pyrrole and benzene rings form a dihedral angle of 81.92 (7)°. The molecule contains an intramolecular O—H...O hydrogen bond. In the crystal, weak C—H...π interactions link the molecules into chains along [010].


IUCrData ◽  
2016 ◽  
Vol 1 (12) ◽  
Author(s):  
Ahmed Moussaif ◽  
Youssef Ramli ◽  
Nada Kheira Sebbar ◽  
El Mokhtar Essassi ◽  
Joel T. Mague

The asymmetric unit of the title compound, C9H8N2S, consists of two independent molecules (AandB) differing in the conformation of the thiazole ring: twisted for moleculeAand planar for moleculeB. In the crystal, molecules stack along thecaxis in alternatingAandBlayers. Within the layers, molecules are linked by C—H...π interactions, and inversion-relatedBmolecules are linked by offset π–π interactions [inter-centroid distance = 3.716 (1) Å]. The two molecules are also linked by a C—H...N hydrogen bond, which results finally in the formation of a three-dimensional structure.


IUCrData ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Gamal A. El-Hiti ◽  
Bakr F. Abdel-Wahab ◽  
Rizk E. Khidre ◽  
Mohamed S. Mostafa ◽  
Amany S. Hegazy ◽  
...  

In the title compound, C24H22N4O2S, the dihedral angle between the triazole and thiophene rings is 4.83 (14)°. The dihedral angles between the triazole and tolyl rings and between the thiophene and phenyl rings are 48.42 (16) and 9.23 (13)°, respectively. An intramolecular N—H...O hydrogen bond closes anS(6) loop. In the crystal, molecules are stacked parallel to thea-axis direction with weak π–π interactions between adjacent thiophenyl and triazolyl groups within the stack [centroid–centroid separation = 3.9811 (16) Å].


Author(s):  
Ying Liang ◽  
Li-Qiao Shi ◽  
Zi-Wen Yang

In the title compound, C19H13ClF2N2O2, the conformation of the N—H bond in the amide segment isantito the C=O bond. The molecule is not planar, with dihedral angles between the central benzene ring and the outer benzene and pyridyl rings of 73.35 (7) and 81.26 (6)°, respectively. A weak intramolecular C—H...O hydrogen bond occurs. In the crystal, N—H...N, C—H...O and C—H...F hydrogen bonds lead to the formation of dimers. The N—H...N inversion dimers are linked by π–π contacts between adjacent pyridine rings [centroid–centroid = 3.8541 (12) Å] and C—H...π interactions. These contacts combine to stack the molecules along theaaxis.


Author(s):  
Qi-Di Zhong ◽  
Sheng-Quan Hu ◽  
Hong Yan

In the title compound, C13H12N2O2(I), the mean planes of the pyrrole and benzyl rings are approximately perpendicular, forming a dihedral angle of 87.07 (4) °. There is an intramolecular N—H...O hydrogen bond forming an S(7) ring motif. In the crystal, molecules are linkedviaa pair of N—H...O hydrogen bonds forming inversion dimers. C—H...O hydrogen bonds link the dimers into chains along direction [10-1]. The chains are further linked by weak C—H...π interactions forming layers parallel to theacplane.


2015 ◽  
Vol 71 (8) ◽  
pp. m152-m153 ◽  
Author(s):  
Liubov M. Lifshits ◽  
Charles Campana ◽  
Jeremy K. Klosterman

The structure of the polymeric title compound, {[Zn2(C20H11NO4)2(C3H7NO)2(CH3OH)]·C3H7NO}n, comprises carbazolylisophthalate moieties connecting dimetallic tetracarboxylate zinc secondary building units (SBUs) parallel to [100] and [010], leading to a layer-like arrangement parallel to (001). Each SBU consists of two Zn atoms in slightly distorted tetrahedral and octahedral coordination environments [Zn...Zn = 3.5953 (6) Å]. Three carboxylate groups bridge the two Zn atoms in a μ2-O:O′ mode, whereas the fourth coordinates through a single carboxylate O atom (μ1-O). The O atoms of two dimethylformamide (DMF) and one methanol molecule complete the Zn coordination spheres. The methanol ligand interacts with the noncoordinating DMF moleculeviaan O—H...O hydrogen bond of medium strength. Carbazoles between the layers interdigitate through weak C—H....π interactions to form a laminar solid stacked along [010]. Two kinds of C—H...π interactions are present, both with a distance of 2.64 Å, between the H atoms and the centroids, and a third C—H...π interaction, where the aromatic H atom is located above the carbazole N-atom lone pair (H...N = 2.89 Å). Several C—H...O interactions occur between the coordinating DMF molecule, the DMF solvent molecule, and ligating carboxylate O atoms.


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