scholarly journals Crystal structure of 1,4-diethoxy-9,10-anthraquinone

2015 ◽  
Vol 71 (7) ◽  
pp. o504-o505 ◽  
Author(s):  
Chitoshi Kitamura ◽  
Sining Li ◽  
Munenori Takehara ◽  
Yoshinori Inoue ◽  
Katsuhiko Ono ◽  
...  

The asymmetric unit of the title compound, C18H16O4, contains two crystallographically independent molecules. The anthraquinone ring systems are slightly bent with dihedral angles of 2.33 (8) and 13.31 (9)° between the two terminal benzene rings. In the crystal, the two independent molecules adopt slipped-parallel π-overlap with an average interplanar distance of 3.45 Å, forming a dimer; the centroid–centroid distances of the π–π interactions are 3.6659 (15)–3.8987 (15) Å. The molecules are also linked by C—H...O interactions, forming a tape structure along thea-axis direction. The crystal packing is characterized by a dimer-herringbone pattern.

Author(s):  
S. Sathya ◽  
D. Reuben Jonathan ◽  
J. Sidharthan ◽  
R. Vasanthi ◽  
G. Usha

The title compound, C27H26O3, crystallized with two independent molecules (AandB) in the asymmetric unit. In moleculeA, the plane of the central benzene ring forms dihedral angles of 75.78 (14) and 52.75 (16)° with that of the terminal benzene rings, and the dihedral angle between the planes of the terminal benzene rings is 51.49 (17)°. The corresponding values for moleculeBare 75.18 (14), 58.11 (16) and 47.91 (16)°, respectively. The cyclohexene ring adopts an envelope conformation in both molecules, with the C atom to which is attached the central benzene ring as the flap. The crystal packing, is stabilized by C—H...π interactions.


2014 ◽  
Vol 70 (10) ◽  
pp. o1122-o1123
Author(s):  
Julio Zukerman-Schpector ◽  
I. Caracelli ◽  
Hélio A. Stefani ◽  
Amna N. Khan ◽  
Edward R. T. Tiekink

In the title compound, C15H20BrNO2, there are two independent molecules (AandB) comprising the asymmetric unit and these adopt very similar conformations. InA, the dihedral angle between the CO2and MeC=CMe2groups is 80.7 (3)°, and these make dihedral angles of 3.5 (3) and 84.09 (16)°, respectively, with the bromobenzene ring. The equivalent dihedral angles for moleculeBare 78.4 (3), 2.1 (3) and 78.37 (12)°, respectively. The most prominent interactions in the crystal packing are amine-N—H...O(carbonyl) hydrogen bonds between the two independent molecules, resulting in non-centrosymmetric ten-membered {...OC2NH}2synthons. Statistical disorder is noted for each of the terminal methyl groups of the ethyl residues.


2017 ◽  
Vol 73 (9) ◽  
pp. 1312-1315
Author(s):  
Hyunjin Park ◽  
Jineun Kim ◽  
Hojae Chiang ◽  
Tae Ho Kim

The title compound, C16H14F5N5O5S [systematic name: 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy-1,2,4-triazolo[1,5-c]pyrimidin-2-yl)-6-(trifluoromethyl)benzenesulfonamide], is used as a herbicide. The asymmetric unit of this structure comprises two independent molecules,AandB. The dihedral angles between the ring planes of the triazolopyrimidine ring systems and the benzene rings are 68.84 (7)° forAand 68.05 (6)° forB. In the crystal, weak intermolecular π–π interactions, with centroid–centroid separations of 3.4456 (17) and 3.5289 (15) Å and C—F...π [3.5335 (17) Å and 107.92 (13)°] contacts link adjacent molecules into chains along [001]. C—H...O and C—H...F hydrogen bonds link typeBmolecules into chains parallel to (100). Additional C—H...F hydrogen bonds together with short F...F contacts further aggregate the structure into a three-dimensional network.


2012 ◽  
Vol 68 (6) ◽  
pp. o1674-o1674 ◽  
Author(s):  
Xin Wu ◽  
Cai-Xia Yuan ◽  
Ling Ma ◽  
Kai-Lu Zhai ◽  
Miao-Li Zhu

The asymmetric unit of the title compound, C12H13BrN4OS, contains two independent molecules in which the dihedral angles between the triazole and benzene rings are 2.9 (3) and 7.5 (3)°. The thione group is of the form R 2C=S. An intramolecular O—H...N hydrogen bond occurs in each molecule. The crystal structure features weak N—H...S interactions and π–π stacking of the benzene rings [centroid–centroid distance = 3.667 (3) Å].


2009 ◽  
Vol 65 (6) ◽  
pp. o1416-o1416 ◽  
Author(s):  
Jian-Cheng Zhou ◽  
Nai-Xu Li ◽  
Chuan-Ming Zhang ◽  
Zheng-Yun Zhang

The asymmetric unit of the title compound, C22H26N2O, contains three crystallographically independent molecules, in which the aromatic rings are oriented at dihedral angles of 21.74 (5), 27.59 (5) and 27.87 (5)°. Intramolecular O—H...N hydrogen bonds result in the formation of planar six-membered rings, and these are nearly coplanar with the adjacent rings. In the crystal structure, π–π contacts between the benzene rings [centroid–centroid distances = 3.989 (2), 3.802 (1) and 3.882 (1) Å] may stabilize the structure.


2012 ◽  
Vol 68 (8) ◽  
pp. o2445-o2446 ◽  
Author(s):  
Aliakbar Dehno Khalaji ◽  
Mahsa Nikookar ◽  
Karla Fejfarová ◽  
Michal Dušek

The crystal structure of the title compound, C14H12N2O4, contains four crystallographically independent molecules in the asymmetric unit. All the molecules have similar conformations; the dihedral angles between the aromatic rings are 33.1 (1), 33.76 (9), 31.41 (9) and 32.56 (10)°. Intramolecular O—H...N hydrogen bonds formS(6) ring motifs in each molecule. In the crystal, there are two pairs of pseudo-inversion-related molecules. Along thecaxis, molecules are stacked with π–π interactions between the 2-hydroxyphenyl and 4-methoxy-2-nitrophenyl rings [centroid–centroid distances = 3.5441 (12)–3.7698 (12) Å].


2014 ◽  
Vol 70 (8) ◽  
pp. o881-o882
Author(s):  
Cai-Xia Yuan ◽  
Shu-Fen Lan ◽  
Xin-Yu Liu ◽  
Miao-Li Zhu

The title compound, C11H11BrN4OS, crystallized as a racemic twin with two symmetry-independent molecules in the asymmetric unit. The dihedral angles between the benzene and triazole rings of the two independent molecules are 56.41 (18) and 54.48 (18)°. An intramolecular O—H...N hydrogen bond occurs in each molecule. In the crystal, pairs of symmetry-independent molecules are linked by pairs of almost linear N—H...S hydrogen bonds, forming cyclic dimers characterized by anR22(8) motif. There are weak π–π interactions between the benzene rings of symmetry-independent molecules, with a centroid–centroid distance of 3.874 (3) Å.


2012 ◽  
Vol 68 (6) ◽  
pp. o1607-o1607 ◽  
Author(s):  
H. C. Devarajegowda ◽  
S. Jeyaseelan ◽  
R. Sathishkumar ◽  
Agnes Sylvia D'souza ◽  
Alphonsus D'souza

In the asymmetric unit of the title compound, C10H9FN4S, there are two independent molecules in which the dihedral angles between the 1,2,4-triazole and benzene rings are 36.85 (10) and 7.81 (10)°. In the crystal, N—H...S interactions link pairs of independent molecules into dimers. There are also π–π interactions between the triazole and benzene rings of inversion-related pairs of the more planar molecule [centroid–centroid distance = 3.6430 (13) Å].


2013 ◽  
Vol 69 (2) ◽  
pp. o253-o253
Author(s):  
Thothadri Srinivasan ◽  
Panneerselvam Yuvaraj ◽  
Boreddy S. R. Reddy ◽  
Devadasan Velmurugan

The asymmetric unit of the title compound, C18H14ClNO3, contains two independent molecules (AandB). In both molecules, the cyclohexanone ring has a chair conformation. The dihedral angles between the pyran ring and the pyridine and chlorophenyl rings are 2.13 (9) and 2.19 (9)°, respectively, inA, and 0.82 (9) and 1.93 (9)°, respectively, inB. The carbonyl O atoms deviate from the pyran and benzene rings to which they are attached by −0.092 (2) and 0.064 (2) Å, respectively, inA, and by −0.080 (2) and −0.063 (2) Å, respectively, inB. In the crystal, theAmolecules are linkedviaC—H...O hydrogen bonds, forming double-stranded chains along [100]. They lie parallel to the double-stranded chains formed by theBmolecules, which are also linkedviaC—H...O hydrogen bonds. The chains stack up thecaxis in an –A–A–B–B–A–A– manner, with a number of π–π interactions involvingAandBmolecules; the centroid–centroid distances vary from 3.4862 (11) to 3.6848 (11) Å


2015 ◽  
Vol 71 (5) ◽  
pp. o309-o310
Author(s):  
Zhiwei Chen ◽  
Graeme J. Moxey

The title compound, C18H19I, crystallized with two independent molecules (AandB) in the asymmetric unit. Both molecules have anEconformation about the bridging C=C bond. They differ in the orientation of the two benzene rings; the dihedral angle being 12.3 (5)° in moleculeA, but only 1.0 (6)° in moleculeB. In the crystal, the individual molecules are linked by C—I...π interactions forming zigzagAand zigzagBchains propagating along [001]. The structure was refined as an inversion twin [Flack parameter = 0.48 (2)].


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