scholarly journals Thermodynamic Effect of Complementary Hydrogen Bond Base Pairing on Aromatic Stacking Interaction in the Guanine-X-Trp Complex (X=Adenine, Guanine, Cytosine, Thymin.

1996 ◽  
Vol 44 (11) ◽  
pp. 1998-2002 ◽  
Author(s):  
Mariko TARUI ◽  
Noriko NOMOTO ◽  
Yoko HASEGAWA ◽  
Katsuhiko MINOURA ◽  
Mitsunobu DOI ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Base Pairing ◽  
Stacking Interaction ◽  
Aromatic Stacking ◽  
Thermodynamic Effect

scholarly journals Isomers and polymorphs of (E,E)-1,4-bis(nitrophenyl)-2,3-diaza-1,3-butadienes

2006 ◽  
Vol 62 (4) ◽  
pp. 666-675 ◽  
Author(s):  
Christopher Glidewell ◽  
John N. Low ◽  
Janet M. S. Skakle ◽  
James L. Wardell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Stacking Interactions ◽  
Space Group ◽  
Stacking Interaction ◽  
Space Groups ◽  
Π Stacking ◽  
Π Stacking Interaction ◽  
Polymorphic Forms

The structures of five of the possible six isomers of (E,E)-1,4-bis(nitrophenyl)-2,3-diaza-1,3-butadiene are reported, including two polymorphs of one of the isomers. (E,E)-1,4-Bis(2-nitrophenyl)-2,3-diaza-1,3-butadiene, C14H10N4O4 (I), crystallizes in two polymorphic forms (Ia) and (Ib) in which the molecules lie across centres of inversion in space groups P21/n and P21/c, respectively: the molecules in (Ia) and (Ib) are linked into chains by aromatic π...π stacking interactions and C—H...π(arene) hydrogen bonds, respectively. Molecules of (E,E)-1-(2-nitrophenyl)-4-(3-nitrophenyl)-2,3-diaza-1,3-butadiene (II) are linked into sheets by two independent C—H...O hydrogen bonds. The molecules of (E,E)-1,4-bis(3-nitrophenyl)-2,3-diaza-1,3-butadiene (III) lie across inversion centres in the space group P21/n, and a combination of a C—H...O hydrogen bond and a π...π stacking interaction links the molecules into sheets. A total of four independent C—H...O hydrogen bonds link the molecules of (E,E)-1-(3-nitrophenyl)-4-(4-nitrophenyl)-2,3-diaza-1,3-butadiene (IV) into sheets. In (E,E)-1,4-bis(4-nitrophenyl)-2,3-diaza-1,3-butadiene (V) the molecules, which lie across centres of inversion in the space group P21/n, are linked by just two independent C—H...O hydrogen bonds into a three-dimensional framework.

scholarly journals 1-Benzyl-2-[(2RS,3SR,6SR)-3-methyl-4-oxo-2,6-diphenylpiperidin-1-ylcarbonyl]-2-phenylethenyl phenylacetate

2006 ◽  
Vol 62 (4) ◽  
pp. o1443-o1445
Author(s):  
Kanagasabapathy Thanikasalam ◽  
Ramasubbu Jeyaraman ◽  
Krishnaswamy Panchanatheswaran ◽  
John N. Low ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Title Compound ◽  
Stacking Interaction ◽  
Compound C ◽  
Π Stacking ◽  
Π Stacking Interaction

Molecules of the title compound, C42H37NO4, are weakly linked into chains by a C—H...O hydrogen bond and pairs of such chains are linked by a single aromatic π–π stacking interaction.

(2RS,4SR)-7-Bromo-2-exo-(2-chlorophenyl)-2,3,4,5-tetrahydro-1,4-epoxynaphtho[1,2-b]azepine: sheets built by the π-stacking of hydrogen-bonded chains

2012 ◽  
Vol 68 (3) ◽  
pp. o123-o125 ◽  
Author(s):  
Andrés F. Yépes ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Title Compound ◽  
Stacking Interaction ◽  
Compound C ◽  
Π Stacking ◽  
Sheet Structure ◽  
Π Stacking Interaction ◽  
Hydrogen Bonded

The molecules of the title compound, C20H15BrClNO, are linked into chains by a C—H...π(arene) hydrogen bond, in which the acceptor is the brominated ring of the naphthalene unit, and these chains are linked by an aromatic π–π stacking interaction, again involving the naphthalene unit, into a sheet structure.

scholarly journals Dependency of the regio- and stereoselectivity of intramolecular, ring-closing glycosylations upon the ring size

2011 ◽  
Vol 7 ◽  
pp. 1609-1619 ◽  
Author(s):  
Patrick Claude ◽  
Christian Lehmann ◽  
Thomas Ziegler
Keyword(s):  
Molecular Modeling ◽  
Protecting Groups ◽  
Ring Size ◽  
Stacking Interaction ◽  
Aromatic Stacking ◽  
Pentafluorophenyl Ester ◽  
Intramolecular Ring

Phenyl 3,4,6-tri-O-benzyl-2-O-(3-carboxypropionyl)-1-thio-β-D-galactopyranoside (1) was condensed via its pentafluorophenyl ester 2 with 5-aminopentyl (4a), 4-aminobutyl (4b), 3-aminopropyl (4c) and 2-aminoethyl 4,6-O-benzylidene-β-D-glucopyranoside (4d), prepared from the corresponding N-Cbz protected glucosides 3a–d, to give the corresponding 2-[3-(alkylcarbamoyl)propionyl] tethered saccharides 5a–d. Intramolecular, ring closing glycosylation of the saccharides with NIS and TMSOTf afforded the tethered β(1→3) linked disaccharides 6a–c, the α(1→3) linked disaccharides 7a–d and the α(1→2) linked disaccharide 8d in ratios depending upon the ring size formed during glycosylation. No β(1→2) linked disaccharides were formed. Molecular modeling of saccharides 6–8 revealed that a strong aromatic stacking interaction between the aromatic parts of the benzyl and benzylidene protecting groups in the galactosyl and glucosyl moieties was mainly responsible for the observed regioselectivity and anomeric selectivity of the ring-closing glycosylation step.

The formation of paracetamol (acetaminophen) adducts with hydrogen-bond acceptors

2002 ◽  
Vol 58 (6) ◽  
pp. 1057-1066 ◽  
Author(s):  
Iain D. H. Oswald ◽  
David R. Allan ◽  
Pamela A. McGregor ◽  
W. D. Samuel Motherwell ◽  
Simon Parsons ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Systematic Study ◽  
Guest Molecule ◽  
Guest Molecules ◽  
Oh Groups ◽  
Stacking Interaction ◽  
Hydrogen Bond Interactions ◽  
Π Stacking Interaction ◽  
Graph Set

The crystal structures of five hemiadducts of paracetamol with 1,4-dioxane, N-methylmorpholine, morpholine, N,N-dimethylpiperazine and piperazine and a related 1:1 adduct of paracetamol with 4,4′-bipyridine are described. All structures are characterized by the formation of chains of paracetamol molecules, which are linked via either OH...O=C interactions [C(9) chains in graph-set notation] or NH...O=C interactions [C(4) chains], depending on the presence or absence of substituent groups on the guest molecule. In all cases except for the morpholine and bipyridine adducts these chains are connected by hydrogen-bond interactions with the guest molecules, which reside on crystallographic inversion centres. In the bipyridine adduct this linkage also involves a π-stacking interaction; in the morpholine adduct it is formed between the OH groups of two opposed paracetamol molecules. Most adducts (that with 4,4′-bipyridine is an exception) decompose on heating to give monoclinic paracetamol. This is the first systematic study of a series of co-crystals containing paracetamol.

scholarly journals A world beyond double-helical nucleic acids: the structural diversity of tetra-stranded G-quadruplexes

ChemTexts ◽  
2021 ◽  
Vol 7 (4) ◽  
Author(s):  
Klaus Weisz
Keyword(s):  
Hydrogen Bond ◽  
Nucleic Acids ◽  
Genetic Information ◽  
Structural Diversity ◽  
Base Pairing ◽  
Rna Sequences ◽  
Dna And Rna ◽  
Regulatory Functions ◽  
Insight Into

AbstractNucleic acids can adopt various secondary structures including double-, triple-, and tetra-stranded helices that differ by the specific hydrogen bond mediated pairing pattern between their nucleobase constituents. Whereas double-helical DNA relies on Watson–Crick base pairing to play a prominent role in storing genetic information, G-quadruplexes are tetra-stranded structures that are formed by the association of guanine bases from G-rich DNA and RNA sequences. During the last few decades, G-quadruplexes have attracted considerable interest after the realization that they form and exert regulatory functions in vivo. In addition, quadruplex architectures have also been recognized as versatile and powerful tools in a growing number of technological applications. To appreciate the astonishing structural diversity of these tetra-stranded structures and to give some insight into basic interactions that govern their folding, this article gives an overview of quadruplex structures and rules associated with the formation of different topologies. A brief discussion will also focus on nonconventional quadruplexes as well as on general principles when targeting quadruplexes with ligands. Graphic abstract

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