scholarly journals The crystal structures of two chalcones: (2E)-1-(5-chlorothiophen-2-yl)-3-(2-methylphenyl)prop-2-en-1-one and (2E)-1-(anthracen-9-yl)-3-[4-(propan-2-yl)phenyl]prop-2-en-1-one

2016 ◽  
Vol 72 (8) ◽  
pp. 1153-1158 ◽  
Author(s):  
Marisiddaiah Girisha ◽  
Hemmige S. Yathirajan ◽  
Jerry P. Jasinski ◽  
Christopher Glidewell

In the crystal of compound (I), C14H11ClOS, molecules are linked by C—H...O hydrogen bonds to form simpleC(5) chains. Compound (II), C26H22O, crystallizes withZ′ = 2 in space groupP-1; one of the molecules is fully ordered but the other is disordered over two sets of atomic sites having occupancies 0.644 (3) and 0.356 (3). The two disordered components differ from one another in the orientation of the isopropyl substituents, and both differ from the ordered molecules in the arrangement of the central propenone spacer unit, so that the crystal of (II) contains three distinct conformers. The ordered and disordered conformers each form aC(8) chain built from a single type of C—H...O hydrogen bond but those formed by the disordered conformers differ from that formed by the ordered form.

2015 ◽  
Vol 71 (9) ◽  
pp. 1003-1009 ◽  
Author(s):  
Padmanabha S. Manjula ◽  
Balladka K. Sarojini ◽  
Hemmige S. Yathirajan ◽  
Mehmet Akkurt ◽  
Cem Cüneyt Ersanlı ◽  
...  

The structures of three 3-methyl-1H-1,2,4-triazole-5-thione derivatives are reported. The structure of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C3H6N4S, (I), has been redetermined with an improved model for the H atoms: the non-H atoms of (I) all lie on mirror planes in space groupPbcm, and the H atoms of the methyl group are disordered over two sets of reflection-related atomic sites having occupancy 0.5: two independent N—H...S hydrogen bonds link the molecules of compound (I) into complex sheets. The non-H atoms in the molecules of 4-[(E)-(3,4-dimethoxybenzylidene)amino]-3-methyl-1H-1,2,4-triazol-5(4H)-thione, C12H14N4O2S, (II), despite lying in general positions are close to planar, with a dihedral angle between the two rings of 6.31 (10)°: the molecules of compound (II) are linked by a three-centre N—H...(O)2hydrogen bond into aC(10)C(11)[R12(5)] chain of rings. A second polymorph of 4-[(E)-(5-bromo-2-hydroxy-5-bromobenzylidene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C10H9BrN4OS, (III), has been identified; the non-H atoms are nearly co-planar with a dihedral angle between the two rings of 1.9 (4)°. There is an intramolecular O—H...N hydrogen bond and the molecules are linked by N—H...S hydrogen bonds, forming centrosymmetricR22(8) dimers. Comparisons are made with some related structures.


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):  
Dilovan S. Cati ◽  
Helen Stoeckli-Evans

The title compounds, C32H28N10O4· unknown solvent, (I), and C32H28N10O4, (II), are pyrazine-2,3,5,6-tetracarboxamide derivatives. In (I), the substituents are (pyridin-2-ylmethyl)carboxamide, while in (II), the substituents are (pyridin-4-ylmethyl)carboxamide. Both compounds crystallize in the monoclinic space groupP21/n, withZ′ = 1 for (I), andZ′ = 0.5 for (II). The whole molecule of (II) is generated by inversion symmetry, the pyrazine ring being situated about a center of inversion. In (I), the four pyridine rings are inclined to the pyrazine ring by 83.9 (2), 82.16 (18), 82.73 (19) and 17.65 (19)°. This last dihedral angle involves a pyridine ring that is linked to the adjacent carboxamide O atom by an intramolecular C—H...O hydrogen bond. In compound (II), the unique pyridine rings are inclined to the pyrazine ring by 33.3 (3) and 81.71 (10)°. There are two symmetrical intramolecular C—H...O hydrogen bonds present in (II). In the crystal of (I), molecules are linked by N—H...O and N—H...N hydrogen bonds, forming layers parallel to (10-1). The layers are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional framework. In the crystal of (II), molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [010] direction. The chains are linked by a weaker N—H...N hydrogen bond, forming layers parallel to the (101) plane, which are in turn linked by C—H...O hydrogen bonds, forming a three-dimensional structure. In the crystal of compound (I), a region of disordered electron density was treated with the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst. C71, 9–18]. Their contribution was not taken into account during refinement. In compound (II), one of the pyridine rings is positionally disordered, and the refined occupancy ratio for the disordered Car—Car—Npyatoms is 0.58 (3):0.42 (3).


Author(s):  
Július Sivý ◽  
Dušan Bortňák ◽  
Daniel Végh ◽  
Erik Rakovský

The crystals, C11H4BrF5N2S, (I), 1-((4-bromothiophen-2-yl)methylene)-2-(perfluorophenyl)hydrazine and C12H6BrF5N2S, (II), 1-((4-bromo-5-methylthiophen-2-yl)methylene)-2-(perfluorophenyl)hydrazine are molecules with two rings and hydrazone part like a centre of the molecule. The compounds have been synthesized and characterized by elemental, spectroscopic (1H-NMR) analysis. The crystal structures of the solid phase were determined by single crystal X-ray diffraction method. They crystallize in the monoclinic space group with Z = 4 and Z = 2 molecules per unit-cell. The compound (I) crystallizes as a racemate in the centrosymmetric space group and the compound (II) crystallizes as a non-racemate in the non-centrosymmetric space group. The “absolute configuration and conformation for bond values” were derived from the anomalous dispersion (ad) for (II). The crystal structures are revealed diverse non-covalent interactions such as intra- and interhydrogen bonding, π-ring···π-ring, C-H···π-ring and they were investigated. The expected stereochemistry of hydrazones atoms C7, N2 and N1 were confirmed for (I) and (II). The hole molecule of the (I), and (II) possesses “a boat conformation” like a 6-membered ring. The results of the single crystal studies are reproduced with the help of Hirshfeld surface study and Gaussian software.


Author(s):  
Julian Radtke ◽  
Hans-Wolfram Lerner ◽  
Michael Bolte

We have encountered two polymorphs of the title compound, C24H16B2OS2, both of which display almost the same unit-cell parameters. Compound (I) crystallizes in the non-centrosymmetric space group P21 with four molecules in the asymmetric unit. These molecules are related by pseudosymmetry. As a result, the space group looks like P21/c, but the structure cannot be refined successfully in that space group. Compound (II) on the other hand crystallizes in the centrosymmetric space group P21/c with only two molecules in the asymmetric unit. The crystals studied for (I) and (II) were both non-merohedral twins.


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.


2017 ◽  
Vol 73 (3) ◽  
pp. 287-297 ◽  
Author(s):  
Farahnaz Hamzehee ◽  
Mehrdad Pourayoubi ◽  
Marek Nečas ◽  
Duane Choquesillo-Lazarte

The N—H...O hydrogen bond is the characteristic interaction in the crystal structures of N-benzyl-P-phenyl-N′-(p-tolyl)phosphonic diamide, C20H21N2OP or (C6H5)P(O)(NHCH2C6H5)(NHC6H4-p-CH3), (I), diphenylphosphinic 1-methylpropylamide, C16H20NOP or (C6H5)2P(O)[NHCH(CH3)(C2H5)], (II), (S)-1-phenylethylammonium N-[(S)-1-phenylethyl]phenylphosphonamidate, C8H12N+·C14H15NO2P− or [S-(C6H5)CH(CH3)NH3][(C6H5)P(O){S-NHCH(CH3)(C6H5)}(O)], (III), and (4-methylbenzyl)ammonium diphenylphosphinate, C8H12N+·C12H10O2P− or [4-CH3-C6H4CH2NH3][(C6H5)2P(O)(O)], (IV). This article focuses on the N—H...O hydrogen bonds by considering the structures of (I), (II), (III) and (IV), and reviewing their analogous compounds, including 43 (C)P(O)(N)2, 102 (C)2P(O)(N), 31 (C)P(O)(N)(O) and 96 (C)2P(O)(O) structures, deposited in the Cambridge Structural Database (CSD). For the structures with a (C)P(O)(N)2 segment, only neutral hydrogen bonds were found in the CSD. The other three classes of compounds included both neutral and `charge-assisted' hydrogen bonds, and the (C)2P(O)(O) structures were particularly noticeable for a high number of cation–anion compounds. The overall tendencies of N...O distances in neutral and cation–anion compounds were compared. The N—H...O hydrogen-bond angles were also analyzed for the four classes of phosphorus compounds.


2006 ◽  
Vol 62 (4) ◽  
pp. 651-665 ◽  
Author(s):  
Silvia Cuffini ◽  
Christopher Glidewell ◽  
John N. Low ◽  
Aline G. de Oliveira ◽  
Marcus V. N. de Souza ◽  
...  

Structures are reported here for eight further substituted N-aryl-2-chloronicotinamides, 2-ClC5H3NCONHC6H4 X-4′. When X = H, compound (I) (C12H9ClN2O), the molecules are linked into sheets by N—H...N, C—H...π(pyridyl) and C—H...π(arene) hydrogen bonds. For X = CH3, compound (II) (C13H11ClN2O, triclinic P\bar 1 with Z′ = 2), the molecules are linked into sheets by N—H...O, C—H...O and C—H...π(arene) hydrogen bonds. Compound (III), where X = F, crystallizes as a monohydrate (C12H8ClFN2O·H2O) and sheets are formed by N—H...O, O—H...O and O—H...N hydrogen bonds and aromatic π...π stacking interactions. Crystals of compound (IV), where X = Cl (C12H8Cl2N2O, monoclinic P21 with Z′ = 4) exhibit inversion twinning: the molecules are linked by N—H...O hydrogen bonds into four independent chains, linked in pairs by C—H...π(arene) hydrogen bonds. When X = Br, compound (V) (C12H8BrClN2O), the molecules are linked into sheets by N—H...O and C—H...N hydrogen bonds, while in compound (VI), where X = I (C12H8ClIN2O), the molecules are linked into a three-dimensional framework by N—H...O and C—H...π(arene) hydrogen bonds and an iodo...N(pyridyl) interaction. For X = CH3O, compound (VII) (C13H11ClN2O2), the molecules are linked into chains by a single N—H...O hydrogen bond. Compound (VIII) (C13H8ClN3O, triclinic P\bar 1 with Z′ = 2), where X = CN, forms a complex three-dimensional framework by N—H...N, C—H...N and C—H...O hydrogen bonds and two independent aromatic π...π stacking interactions.


2016 ◽  
Vol 72 (9) ◽  
pp. 670-678 ◽  
Author(s):  
Tholappanavara H. Suresha Kumara ◽  
Gopalpur Nagendrappa ◽  
Nanjappa Chandrika ◽  
Haliwana B. V. Sowmya ◽  
Manpreet Kaur ◽  
...  

Hydrazone derivatives exhibit a wide range of biological activities, while pyrazolo[3,4-b]quinoline derivatives, on the other hand, exhibit both antimicrobial and antiviral activity, so that all new derivatives in these chemical classes are potentially of value. Dry grinding of a mixture of 2-chloroquinoline-3-carbaldehyde and 4-methylphenylhydrazinium chloride gives (E)-1-[(2-chloroquinolin-3-yl)methylidene]-2-(4-methylphenyl)hydrazine, C17H14ClN3, (I), while the same regents in methanol in the presence of sodium cyanoborohydride give 1-(4-methylphenyl)-4,9-dihydro-1H-pyrazolo[3,4-b]quinoline, C17H15N3, (II). The reactions between phenylhydrazinium chloride and either 2-chloroquinoline-3-carbaldehyde or 2-chloro-6-methylquinoline-3-carbaldehyde give, respectively, 1-phenyl-1H-pyrazolo[3,4-b]quinoline, C16H11N3, (III), which crystallizes in the space groupPbcnas a nonmerohedral twin havingZ′ = 3, or 6-methyl-1-phenyl-1H-pyrazolo[3,4-b]quinoline, C17H13N3, (IV), which crystallizes in the space groupR\overline{3}. The molecules of compound (I) are linked into sheets by a combination of N—H...N and C—H...π(arene) hydrogen bonds, and the molecules of compound (II) are linked by a combination of N—H...N and C—H...π(arene) hydrogen bonds to form a chain of rings. In the structure of compound (III), one of the three independent molecules forms chains generated by C—H...π(arene) hydrogen bonds, with a second type of molecule linked to the chains by a second C—H...π(arene) hydrogen bond and the third type of molecule linked to the chain by multiple π–π stacking interactions. A single C—H...π(arene) hydrogen bond links the molecules of compound (IV) into cyclic centrosymmetric hexamers having \overline{3} (S6) symmetry, which are themselves linked into a three-dimensional array by π–π stacking interactions.


1997 ◽  
Vol 50 (11) ◽  
pp. 1053 ◽  
Author(s):  
Paul D. Ahn, ◽  
Roger Bishop, ◽  
Donald C. Craig ◽  
Gary A. Downing ◽  
Marcia L. Scudder

Reaction of methylmagnesium chloride and pentacyclo[7.3.0.0 2,7.0 3,11 .0 6,10 ]dodecane-8,12-dione (4) yields the C2-symmetric diol (5) (62%) and the unsymmetrical diol (6) (36%) whose crystal structures are analysed in crystal engineering terms. The former isomer is the tenth member of the helical tubuland diol family, crystallizing in space groupP 3121 as a microporous lattice containing empty parallel canals with 9· 9Å2cross-sectional area. Molecules of diol (6) hydrogen bond through (-O-H)4 cycles to form layers which stack in space group P 21/c by means of hydrocarbon dispersion forces. Diol (7), the bis(trifluoromethyl) analogue of (5), does not form a helical tubuland lattice. The structure of its hemihydrate also contains (–O–H)4 cycles but here the second diol hydroxy group hydrogen bonds to water resulting in a network structure in space group P-421c.


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