scholarly journals Hydrogen Bonds and Stacking Interactions on the DNA Structure: A Topological View of Quantum Computing

10.5772/36486 ◽  
2012 ◽  
Author(s):  
Boaz Galdino de Oliveira ◽  
Regiane de Cssia Maritan Ugulino de Arajo
2014 ◽  
Vol 70 (2) ◽  
pp. m35-m35
Author(s):  
Jing-Wei Dai ◽  
Zhao-Yang Li ◽  
Osamu Sato

In the title complex, [Fe(NCS)2(C18H18N4)], the FeIIcation is chelated by a tris(2-pyridylmethyl)amine ligand and coordinated by two thiocyanate anions in a distorted N6octahedral geometry. In the crystal, weak C—H...S hydrogen bonds and π–π stacking interactions between parallel pyridine rings of adjacent molecules [centroid–centroid distance = 3.653 (3) Å] link the molecules into a two-dimensional supramolecular architecture. The structure contains voids of 124 (9) Å3, which are free of solvent molecules.


2014 ◽  
Vol 70 (10) ◽  
pp. o1130-o1130 ◽  
Author(s):  
Wataru Furukawa ◽  
Munenori Takehara ◽  
Yoshinori Inoue ◽  
Chitoshi Kitamura

In an attempt to brominate 1,4-dipropoxy-9,10-anthraquinone, a mixture of products, including the title compound, C14H7BrO4, was obtained. The molecule is essentially planar (r.m.s. deviation = 0.029 Å) and two intramolecular O—H...O hydrogen bonds occur. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds, Br...O contacts [3.240 (5) Å], and π–π stacking interactions [shortest centroid–centroid separation = 3.562 (4) Å], generating a three-dimensional network.


2013 ◽  
Vol 69 (2) ◽  
pp. m73-m74 ◽  
Author(s):  
Sigurd Øien ◽  
David Stephen Wragg ◽  
Karl Petter Lillerud ◽  
Mats Tilset

In the title compound, [Cu2Cl4(C12H8N2O4)2]·4C3H7NO, which contains a chloride-bridged centrosymmetric CuIIdimer, the CuIIatom is in a distorted square-pyramidal 4 + 1 coordination geometry defined by the N atoms of the chelating 2,2′-bipyridine ligand, a terminal chloride and two bridging chloride ligands. Of the two independent dimethylformamide molecules, one is hydrogen bonded to a single –COOH group, while one links two adjacent –COOH groupsviaa strong accepted O—H...O and a weak donated C(O)—H...O hydrogen bond. Two of these last molecules and the two –COOH groups form a centrosymmetric hydrogen-bonded ring in which the CH=O and the –COOH groups by disorder adopt two alternate orientations in a 0.44:0.56 ratio. These hydrogen bonds link the CuIIcomplex molecules and the dimethylformamide solvent molecules into infinite chains along [-111]. Slipped π–π stacking interactions between two centrosymmetric pyridine rings (centroid–centroid distance = 3.63 Å) contribute to the coherence of the structure along [0-11].


2001 ◽  
Vol 58 (1) ◽  
pp. 94-108 ◽  
Author(s):  
Craig J. Kelly ◽  
Janet M. S. Skakle ◽  
James L. Wardell ◽  
Solange M. S. V. Wardell ◽  
John N. Low ◽  
...  

Molecules of N-(4′-iodophenylsulfonyl)-4-nitroaniline, 4-O2NC6H4NHSO2C6H4I-4′ (1), are linked by three-centre I...O2N interactions into chains and these chains are linked into a three-dimensional framework by C—H...O hydrogen bonds. In the isomeric N-(4′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4NHSO2C6H4NO2-4′ (2), the chains generated by the I...O2N interactions are again linked into a three-dimensional framework by C—H...O hydrogen bonds. Molecules of N,N-bis(3′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4N(SO2C6H4NO2-3′)2 (3), lie across twofold rotation axes in space group C2/c and they are linked into chains by paired I...O=S interactions: these chains are linked into sheets by a C—H...O hydrogen bond, and the sheets are linked into a three-dimensional framework by aromatic π...π stacking interactions. In N-(4′-iodophenylsulfonyl)-3-nitroaniline, 3-O2NC6H4NHSO2C6H4I-4′ (4), there are R^2_2(8) rings formed by hard N—H...O=S hydrogen bonds and R^2_2(24) rings formed by two-centre I...nitro interactions, which together generate a chain of fused rings: the combination of a C—H...O hydrogen bond and aromatic π...π stacking interactions links the chains into sheets. Molecules of N-(4′-iodophenylsulfonyl)-4-methyl-2-nitroaniline, 4-CH3-2-O2NC6H3NHSO2C6H4I-4′ (5), are linked by N—H...O=S and C—H...O(nitro) hydrogen bonds into a chain containing alternating R^2_2(8) and R^2_2(10) rings, but there are no I...O interactions of either type. There are two molecules in the asymmetric unit of N-(4′-iodophenylsulfonyl)-2-nitroaniline, 2-O2NC6H4NHSO2C6H4I-4′ (6), and the combination of an I...O=S interaction and a hard N—H...O(nitro) hydrogen bond links the two types of molecule to form a cyclic, centrosymmetric four-component aggregate. C—H...O hydrogen bonds link these four-molecule aggregates to form a molecular ladder. Comparisons are made with structures retrieved from the Cambridge Structural Database.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


2017 ◽  
Vol 73 (11) ◽  
pp. 1700-1703 ◽  
Author(s):  
Suk-Hee Moon ◽  
Joobeom Seo ◽  
Ki-Min Park

The asymmetric unit of the title compound, [Co(NO3)2(C12H12N2S)2]n, contains a bis(pyridin-3-ylmethyl)sulfane (L) ligand, an NO3−anion and half a CoIIcation, which lies on an inversion centre. The CoIIcation is six-coordinated, being bound to four pyridine N atoms from four symmetry-relatedLligands. The remaining coordination sites are occupied by two O atoms from two symmetry-related nitrate anions in a monodentate manner. Thus, the CoIIcentre adopts a distorted octahedral geometry. Two symmetry-relatedLligands are connected by two symmetry-related CoIIcations, forming a 20-membered cyclic dimer, in which the CoIIatoms are separated by 10.2922 (7) Å. The cyclic dimers are connected to each other by sharing CoIIatoms, giving rise to the formation of an infinite looped chain propagating along the [101] direction. Intermolecular C—H...π (H...ring centroid = 2.89 Å) interactions between one pair of correspondingLligands and C—H...O hydrogen bonds between theLligands and the nitrate anions occur in the looped chain. In the crystal, adjacent looped chains are connected by intermolecular π–π stacking interactions [centroid-to-centroid distance = 3.8859 (14) Å] and C—H...π hydrogen bonds (H...ring centroid = 2.65 Å), leading to the formation of layers parallel to (101). These layers are further connected through C—H...O hydrogen bonds between the layers, resulting in the formation of a three-dimensional supramolecular architecture.


Author(s):  
Vasant S. Naik ◽  
Venkataraya Shettigar ◽  
Tyler S. Berglin ◽  
Jillian S. Coburn ◽  
Jerry P. Jasinski ◽  
...  

In the molecules of the title compounds, (2E)-1-(3-bromo-thiophen-2-yl)-3-(2-methoxyphenyl)prop-2-en-1-one, C14H11BrO2S, (I), which crystallizes in the space groupP-1 with four independent molecules in the asymmetric unit (Z′ = 8), and (2E)-1-(3-bromothiophen-2-yl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one, C15H13BrO3S, (II), which crystallizes withZ′ = 8 in the space groupI2/a, the non-H atoms are nearly coplanar. The molecules of (I) pack with inversion symmetry stacked diagonally along thea-axis direction. Weak C—H...Br intramolecular interactions in each of the four molecules in the asymmetric unit are observed. In (II), weak C—H...O, bifurcated three-center intermolecular interactions forming dimers along with weak C—H...π and π–π stacking interactions are observed, linking the molecules into sheets along [001]. A weak C—H...Br intramolecular interaction is also present. There are no classical hydrogen bonds present in either structure.


2018 ◽  
Vol 74 (12) ◽  
pp. 1891-1894
Author(s):  
Priya Antony ◽  
S. Antony Inglebert ◽  
Jerald V. Ramaclus ◽  
S. John Sundaram ◽  
P. Sagayaraj

The title molecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S−·H2O, (II), are stilbazole, or 4-styrylpyridine, derivatives. The cation, (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic molecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetrahedral coordination sphere. In (II), the anion consists of a 4-methoxybenzenesulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π–π stacking interactions involving the pyridinium and benzene rings, with centroid–centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-methoxybenzenesulfonate anions are bridged by Owater—H...Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C—H...O hydrogen bonds, forming slabs lying parallel to the ab plane.


2012 ◽  
Vol 68 (6) ◽  
pp. o1884-o1884 ◽  
Author(s):  
Ísmail Çelik ◽  
Mehmet Akkurt ◽  
Makbule Yilmaz ◽  
Ahmet Tutar ◽  
Ramazan Erenler ◽  
...  

In the title compound, C11H10Br2O2, the cyclopentene ring fused to the benzene ring adopts an envelope conformation, with the C atom attached to the Br atom as the flap. The crystal structure does not exhibit any classical hydrogen bonds. The molecular packing is stabilized by van der Waals forces and π–π stacking interactions with a centroid–centroid distance of 3.811 (4) Å.


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