scholarly journals Crystal structures of 3-fluoro-N-[2-(trifluoromethyl)phenyl]benzamide, 3-bromo-N-[2-(trifluoromethyl)phenyl]benzamide and 3-iodo-N-[2-(trifluoromethyl)phenyl]benzamide

Author(s):  
P. A. Suchetan ◽  
E. Suresha ◽  
S. Naveen ◽  
N. K. Lokanath

In the title compounds, C14H9F4NO, (I), C14H9BrF3NO, (II), and C14H9F3INO, (III), the two benzene rings are inclined to one another by 43.94 (8)° in moleculeAand 55.66 (7)° in moleculeBof compound (I), which crystallizes with two independent molecules in the asymmetric unit, but by only 10.40 (12)° in compound (II) and 12.5 (2)° in compound (III). In the crystals of all three compounds, N—H...O hydrogen bonds link the molecules to form chains propagating along thea-axis direction for (I), and along theb-axis direction for (II) and (III). In the crystal of (I), –A–B–A–B– chains are linked by C—H...O hydrogen bonds, forming layers parallel to (010). Within the layers there are weak offset π–π interactions present [intercentroid distances = 3.868 (1) and 3.855 (1) Å]. In the crystals of (II) and (III), the chains are linkedviashort halogen–halogen contacts [Br...Br = 3.6141 (4) Å in (II) and I...I = 3.7797 (5) Å in (III)], resulting in the formation of ribbons propagating along theb-axis direction.

Author(s):  
Sadashivamurthy Shamanth ◽  
Kempegowda Mantelingu ◽  
Haruvegowda Kiran Kumar ◽  
Hemmige S. Yathirajan ◽  
Sabine Foro ◽  
...  

Three title compounds, namely, 2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]-6-phenylimidazo[2,1-b][1,3,4]thiadiazole, C26H19ClN4S, (I), 2-(4-chlorobenzyl)-6-(4-fluorophenyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazole, C26H18ClFN4S, (II), and 6-(4-bromophenyl)-2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazole, C26H18BrClN4S, (III), have been prepared using a reductive condensation of indole with the corresponding 6-aryl-2-(4-chlorobenzyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehydes (aryl = phenyl, 4-fluorophenyl or 4-bromophenyl), and their crystal structures have been determined. The asymmetric unit of compound (I) consists of two independent molecules and one of the molecules exhibits disorder of the 4-chlorobenzyl substituent with occupancies 0.6289 (17) and 0.3711 (17). Each type of molecule forms a C(8) chain motif built from N—H...N hydrogen bonds, which for the fully ordered molecule is reinforced by C—H...π interactions. In compound (II), the chlorobenzyl unit is again disordered, with occupancies 0.822 (6) and 0.178 (6), and the molecules form C(8) chains similar to those in (I), reinforced by C—H...π interactions involving only the major disorder component. The chlorobenzyl unit in compound (III) is also disordered with occupancies of 0.839 (5) and 0.161 (5). The molecules are linked by a combination of one N—H...N hydrogen bond and four C—H...π interactions, forming a three-dimensional framework.


Author(s):  
Sarah K. Zingales ◽  
Morgan E. Moore ◽  
Andrew D. Goetz ◽  
Clifford W. Padgett

The title compounds C17H14BrNO2, (I), and C17H15NO3, (II), were obtained from the reaction of 6-methoxy-3,4-dihydro-2H-naphthalen-1-one and 2-bromonicotinaldehyde in ethanol. Compound (I) was the expected product and compound (II) was the oxidation product from air exposure. In the crystal structure of compound (I), there are no short contacts or hydrogen bonds. The structure does display π–π interactions between adjacent benzene rings and adjacent pyridyl rings. Compound (II) contains two independent molecules,AandB, in the asymmetric unit; both are non-planar, the dihedral angles between the methoxybenzene and 1H-pyridin-2-one mean planes being 35.07 (9)° inAand 35.28 (9)°inB. In each molecule, the 1H-pyridin-2-one unit participates in intermolecular N—H...O hydrogen bonding to another molecule of the same type (AtoAorBtoB). The structure also displays π–π interactions between the pyridyl and the benzene rings of non-equivalent molecules (viz.,AtoBandBtoA).


2015 ◽  
Vol 71 (9) ◽  
pp. 1036-1041
Author(s):  
S. Gopinath ◽  
K. Sethusankar ◽  
Bose Muthu Ramalingam ◽  
Arasambattu K. Mohanakrishnan

The title compounds, C17H13NO2S, (I), C17H13NO3S, (II), and C24H17ClN2O5S·CHCl3, (III), are indole derivatives. Compounds (I) and (II) crystalize with two independent molecules in the asymmetric unit. The indole ring systems in all three structures deviate only slightly from planarity, with dihedral angles between the planes of the pyrrole and benzene rings spanning the tight range 0.20 (9)–1.65 (9)°. These indole ring systems, in turn, are almost orthogonal to the phenylsulfonyl rings [range of dihedral angles between mean planes = 77.21 (8)–89.26 (8)°]. In the three compounds, the molecular structure is stabilized by intramolecular C—H...O hydrogen bonds, generatingS(6) ring motifs with the sulfone O atom. In compounds (I) and (II), the two independent molecules are linked by C—H...O hydrogen bonds and C—H...π interactions, while in compound (III), the molecules are linked by C—H...O hydrogen bonds, generatingR22(22) inversion dimers.


2019 ◽  
Vol 74 (9) ◽  
pp. 649-663
Author(s):  
Ligia R. Gomes ◽  
John N. Low ◽  
Alan B. Turner ◽  
Alexander W. Nowicki ◽  
Thomas C. Baddeley ◽  
...  

AbstractThe crystal structures and Hirshfeld surface analyses of the des-A-B-aromatic steroid derivative, (3a,9b)-1,2,3a,4,5,9b-hexahydro-7-methoxy-3a-methyl-3H-benz[e]-inden-3-one (or 5-methoxy-des-A-estra-5,7,9-triene-17-one) 1, its acetohydrazide derivative, 2, and its hydrazone derivative, 3, are reported. All three compounds crystallize in chiral space groups: compounds 1 and 2 in the orthorhombic space group P212121 each with one molecule in the asymmetric unit, and compound 3 in the monoclinic space group P21 with two similar but independent molecules, Mol A and Mol B, in the asymmetric unit. Both the five-membered and six-membered non-aromatic rings in all three compounds have envelope or near envelope shapes. In compounds 2 and 3 the N=N units have (E)-arrangements. The intermolecular interactions in crystals of compound 1 are C–H · · · O hydrogen bonds and C–H · · · π interactions, in compound 2 N–H · · · O and C–H · · · O hydrogen bonds and C–H · · · π interactions are present, while in compound 3 there are just C–H · · · π interactions. An important substructure in 1 is a sheet of molecules, composed of ${\rm{R}}_6^6(44)$ rings, formed from C–H · · · O(methoxy) and C–H · · · O(carbonyl) hydrogen bonds, the molecules of which form columns linked via the B and D rings, i.e. in a head-to-tail fashion. Compound 2 is an acylhydrazonyl compound, in which the two independent molecules are linked into asymmetric dimers via strong classical N–H · · · O hydrogen bonds, with the formation of ${\rm{R}}_2^2(8)$ rings. In both 1 and 2, further intermolecular interactions result in 3-dimensional structures, while compound 3 has a 1-dimensional structure arising from C–H · · · O interactions generating spiral chains. The results have been compared with existing data.


2014 ◽  
Vol 70 (5) ◽  
pp. o589-o590 ◽  
Author(s):  
Pumsak Ruanwas ◽  
Suchada Chantrapromma ◽  
Hazem A. Ghabbour ◽  
Hoong-Kun Fun

There are two crystallograpically independent molecules in the asymmetric unit of the title bischalcone derivative, C25H32N2O. Both molecules are twisted with a dihedral angle between the two substituted benzene rings of 11.19 (16)° in one molecule and 14.40 (15)° in the other. The central penta-1,4-dien-3-one fragments make dihedral angles of 8.49 (17) and 4.26 (17)° with the two adjacent benzene rings in one molecule, whereas the corresponding values are 8.42 (16) and 6.18 (16)° in the other. In the crystal, molecules are arranged into chains along thec-axis direction. Adjacent chains are inter-linked by weak intermolecular C—H...O interactions. The crystal is further stabilized by C—H...π interactions.


2015 ◽  
Vol 71 (10) ◽  
pp. 1117-1120 ◽  
Author(s):  
Dmitrijs Stepanovs ◽  
Daniels Posevins ◽  
Maris Turks

The title compounds consist of a bornane skeleton with attached acetamide, C12H21NO (±)-(1) {systematic name: (±)-N-[(1RS,2RS,4RS)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, and chloroacetamide, C12H20ClNO (±)-(2) {systematic name: (±)-2-chloro-N-[(1RS,2RS,4RS)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl]acetamide}, functionalities to the 2-exo-position. The crystal structure of the first monoclinic polymorph of (±)-(1) has been reported previously [Unget al.(2014).Monatsh. Chem.145, 983–992]. Compound (±)-(1) crystallizes in the space groupP21/nwith two independent molecules in the asymmetric unit, in contrast to the above-mentioned polymorph which crystallized in the space groupC2/cwith one molecule in the asymmetric unit. In the title compounds, the bicyclic bornane moieties have normal geometries. In the crystals of both compounds, molecules are linked by N—H...O hydrogen bonds, reinforced by C—H...O contacts, formingtrans-amide chains propagating along thea-axis direction. In the case of compound (±)-(1), neighbouring chains are linked by further C—H...O contacts, forming double-chain ribbons along [100].


2015 ◽  
Vol 71 (12) ◽  
pp. 1488-1492 ◽  
Author(s):  
Yum Eryanti ◽  
Adel Zamri ◽  
Tati Herlina ◽  
Unang Supratman ◽  
Mohd Mustaqim Rosli ◽  
...  

The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hydroxybenzylidene and 2-chlorobenzylidene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O—H...N and O—H...O hydrogen bonds link the molecules, forming chains along [10-1]. The chains are linkedviaC—H...O hydrogen bonds, forming undulating sheets parallel to theacplane. In the crystal of (2), molecules are linked by weak C—H...Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along thea-axis direction by π–π interactions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).


Author(s):  
Md. Serajul Haque Faizi ◽  
Ashanul Haque ◽  
Musheer Ahmad ◽  
Irina A. Golenya

The title compound, C27H20N2, a Schiff base synthesizedviaa condensation reaction between anthracene-9-carbaldehyde andN-phenyl-p-phenylenediamine, crystallizes with three independent molecules in the asymmetric unit. The three molecules have slightly varying overall conformations, all havingtransconformations with respect to the C=N bond. In the crystal, the packing features N—H...N hydrogen bonds, which connect molecules into chains extending along thec-axis direction, interlinked by C—H...π interactions (minimum H...Cg= 2.65 Å) into sheets lying parallel to (001).


Author(s):  
S. Naveen ◽  
A. G. Sudha ◽  
E. Suresha ◽  
N. K. Lokanath ◽  
P. A. Suchetan ◽  
...  

The syntheses and crystal structures of the isomeric 4-bromo-N-[(2-nitrophenyl)sulfonyl]benzamide, (I), and 4-bromo-N-[(4-nitrophenyl)sulfonyl]benzamide, (II), are described (molecular formula = C13H9BrN2O5S in each case). The asymmetric unit of (I) contains two independent molecules [(IA) and (IB)], while that of (II) contains one molecule. The benzoic acid aromatic ring of molecule (IA) is disordered due to rotation about the Car—C(=O) bond over two orientations in a 0.525 (9):0.475 (9) ratio. The dihedral angle between the benzene rings is 85.9 (3)° in (IA) and 65.22 (19)° in (IB), while in (II), the corresponding value is 56.7 (7)°. In the crystals of (I) and (II), N—H...O, C—H...O and C—H...π interactions generate three-dimensional networks.


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.


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