3-Ferrocenyl-6-nitro-2-phenylquinoxaline: Cyclic Centrosymmetric Dimers Depending on both C—H...O Hydrogen Bonds and π-π Stacking Interactions

1998 ◽  
Vol 54 (12) ◽  
pp. 1839-1842 ◽  
Author(s):  
S. Z. Ahmed ◽  
G. Ferguson ◽  
C. Glidewell
2002 ◽  
Vol 58 (4) ◽  
pp. 701-709 ◽  
Author(s):  
Simon J. Garden ◽  
Silvia P. Fontes ◽  
James L. Wardell ◽  
Janet M. S. Skakle ◽  
John N. Low ◽  
...  

Molecules of 2-iodo-5-nitroaniline (I) are linked by N—H...O hydrogen bonds into centrosymmetric dimers and by asymmetric three-centre iodo...nitro interactions into chains, so forming chains of fused centrosymmetric rings: these chains are linked by aromatic π...π stacking interactions to form a three-dimensional structure. In the isomeric 4-iodo-2-nitroaniline (II), each of the two independent molecules forms hydrogen-bonded chains that are linked by two-centre iodo...nitro interactions into sheets of two types, each containing only a single type of molecule: π...π stacking interactions are absent. In 2,4-diiodo-3-nitroaniline (III), where the nitro group is almost orthogonal to the aryl ring, a combination of N—H...O hydrogen bonds and two distinct two-centre iodo...nitro interactions links the molecules into a three-dimensional framework that is reinforced by aromatic π...π stacking interactions. Bond lengths and conformations are discussed and comparisons are drawn with related compounds.


2017 ◽  
Vol 73 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Marisiddaiah Girisha ◽  
Belakavadi K. Sagar ◽  
Hemmige S. Yathirajan ◽  
Ravindranath S. Rathore ◽  
Christopher Glidewell

It has been observed that when electron-rich naphthyl rings are present in chalcones they can participate in π–π stacking interactions, and this can play an important role in orientating inhibitors within the active sites of enzymes, while chalcones containing heterocyclic substituents additionally exhibit fungistatic and fungicidal properties. With these considerations in mind, three new chalcones containing 2-naphthyl substituents were prepared. 3-(4-Fluorophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C19H13FO, (I), crystallizes withZ′ = 2 in the space groupP-1 and the four molecules in the unit cell adopt an arrangement which resembles that in the space groupP21/a. Although 3-(4-bromophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C19H13BrO, (II), withZ′ = 1, is not isostructural with (I), the molecules of (I) and (II) adopt very similar conformations. In 1-(naphthalen-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one, C17H12OS, (III), the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.780 (3) and 0.220 (3), which are related by a near 180° rotation of the thiophene unit about its exocyclic C—C bond. The molecules of compound (I) are linked by three independent C—H...π(arene) hydrogen bonds to form centrosymmetric octamolecular aggregates, whereas the molecules of compound (II) are linked into molecular ladders by a combination of C—H...π(arene) and C—Br...π(arene) interactions, and those of compound (III) are linked into centrosymmetric dimers by C—H...π(thiophene) interactions.


2014 ◽  
Vol 70 (9) ◽  
pp. 920-926 ◽  
Author(s):  
Aletti S. Praveen ◽  
Hemmige S. Yathirajan ◽  
Manpreet Kaur ◽  
Badiadka Narayana ◽  
Eric C. Hosten ◽  
...  

Four imidazo[2,1-b][1,3,4]thiadiazoles containing a simply-substituted 6-aryl group have been synthesized by reaction of 2-amino-1,3,4-thiadiazoles with bromoacetylarenes using microwave irradiation and brief reaction times. 6-(2-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C10H6ClN3S, (I), 6-(2-chlorophenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C11H8ClN3S, (II), 6-(3,4-dichlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C10H5Cl2N3S, (III), and 6-(4-fluoro-3-methoxyphenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C12H10FN3OS, (IV), crystallize withZ′ values of 2, 1, 1 and 2 respectively. The molecular skeletons are all nearly planar and the dihedral angles between the imidazole and aryl rings are 1.51 (8) and 7.28 (8)° in (I), 9.65 (7)° in (II), 10.44 (8)° in (III), and 1.05 (8) and 7.21 (8)° in (IV). The molecules in (I) are linked by three independent C—H...N hydrogen bonds to form ribbons containing alternatingR22(8) andR44(18) rings, and these ribbons are linked into a three-dimensional array by three independent π-stacking interactions. Both (II) and (III) contain centrosymmetric dimers formed by π-stacking interactions but hydrogen bonds are absent, and the molecules of (IV) are linked into centrosymmetricR22(8) dimers by C—H...N hydrogen bonds. Comparisons are made with a number of related compounds.


2013 ◽  
Vol 69 (9) ◽  
pp. 1039-1042
Author(s):  
Jairo Quiroga ◽  
Dayana Pantoja ◽  
Justo Cobo ◽  
Christopher Glidewell

The title compound, C27H25Cl2N3, is an unexpected but high-yield product from the microwave-mediated reaction between 3-tert-butyl-N-4-chlorobenzyl-1-phenyl-1H-pyrazol-5-amine and 4-chlorobenzaldehyde. Inversion-related pairs of molecules are linked by C—H...π(arene) hydrogen bonds to form cyclic centrosymmetric dimers, and dimers of this type are linked into sheets by two independent π–π stacking interactions.


IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Mohamed Samba ◽  
Bahia Djerrari ◽  
Mohamed Said Minnih ◽  
Youssef Ramli ◽  
El Mokhtar Essassi ◽  
...  

The conformation of the title compound, C18H18N4O, is partly determined by an intramolecular N—H...O hydrogen bond that imposes planarity on the central aminoethylidene-3-methylpyrazol-5-one segment of the molecule. In the crystal, N—H...O hydrogen and N—H...N hydrogen bonds both form centrosymmetric dimers that encloseR22(18) rings. These, together with C—H...N and π–π stacking interactions between centrosymmetrically related pyrazalone rings, stack the molecules along theb-axis direction.


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.


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.


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