scholarly journals (E)-2-{[(2-Aminophenyl)imino]methyl}-5-(benzyloxy)phenol and (Z)-3-benzyloxy-6-{[(5-chloro-2-hydroxyphenyl)amino]methylidene}cyclohexa-2,4-dien-1-one

2018 ◽  
Vol 74 (5) ◽  
pp. 737-742
Author(s):  
Nadir Ghichi ◽  
Ali Benboudiaf ◽  
Chawki Bensouici ◽  
Yacine DJebli ◽  
Hocine Merazig
Keyword(s):  
Hydrogen Bond ◽  
Schiff Base ◽  
Density Functional ◽  
Tautomeric Form ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Compound I ◽  
Phenyl Rings ◽  
Imine Bond ◽  
Compound Ii

The title Schiff base compounds, C20H18N2O2(I) and C20H16ClNO3(II), were synthesized from 4-benzyloxy-2-hydroxybenzaldehyde by reaction with 1,2-diaminobenzene for (I), and condensation with 2-amino-4-chlorophenol for (II). Compound (I) adopts the enol–imine tautomeric form with anEconfiguration about the C=N imine bond. In contrast, theo-hydroxy Schiff base (II), is in the keto–imine tautomeric form with aZconfiguration about the CH—NH bond. Neither molecule is planar. In (I), the central benzene ring makes dihedral angles of 46.80 (10) and 78.19 (10)° with the outer phenylamine and phenyl rings, respectively, while for (II), the corresponding angles are 5.11 (9) and 58.42 (11)°, respectively. The molecular structures of both compounds are affected by the formation of intramolecular contacts, an O—H...N hydrogen bond for (I) and an N—H...O hydrogen bond for (II); each contact generates anS(6) ring motif. In the crystal of (I), strong N—H...O hydrogen bonds form zigzag chains of molecules along theb-axis direction. Molecules are further linked by C—H...π interactions and offset π–π contacts and these combine to form a three-dimensional network. The density functional theory (DFT) optimized structure of compound (II), at the B3LYP/6–311+G(d) level, confirmed that the keto tautomeric form of the compound, as found in the structure determination, is the lowest energy form. The antioxidant capacities of both compounds were determined by the cupric reducing antioxidant capacity (CUPRAC) process.

scholarly journals Crystal structures ofN2,N3,N5,N6-tetrakis(pyridin-2-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide andN2,N3,N5,N6-tetrakis(pyridin-4-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide

2017 ◽  
Vol 73 (2) ◽  
pp. 300-305
Author(s):  
Dilovan S. Cati ◽  
Helen Stoeckli-Evans
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Monoclinic Space Group ◽  
Compound I ◽  
Acta Cryst ◽  
Pyrazine Ring ◽  
Bond Forming ◽  
Compound Ii

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).

scholarly journals Crystal structures of three 6-aryl-2-(4-chlorobenzyl)-5-[(1H-indol-3-yl)methyl]imidazo[2,1-b][1,3,4]thiadiazoles

2020 ◽  
Vol 76 (1) ◽  
pp. 18-24
Author(s):  
Sadashivamurthy Shamanth ◽  
Kempegowda Mantelingu ◽  
Haruvegowda Kiran Kumar ◽  
Hemmige S. Yathirajan ◽  
Sabine Foro ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Compound I ◽  
Π Interactions ◽  
Reductive Condensation ◽  
Independent Molecules ◽  
Compound Ii

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.

scholarly journals Nine N-aryl-2-chloronicotinamides: supramolecular structures in one, two and three dimensions

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 ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Supramolecular Structures ◽  
Three Dimensions ◽  
Compound Viii ◽  
Stacking Interactions ◽  
Compound I ◽  
Π Stacking ◽  
Compound Ii

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.

scholarly journals Steric repulsion and supramolecular assemblies via a two-dimensional plate by C—H...O hydrogen bonds in two closely related 2-(benzofuran-2-yl)-2-oxoethyl benzoates

2017 ◽  
Vol 73 (8) ◽  
pp. 1227-1231
Author(s):  
Li Yee Then ◽  
C. S. Chidan Kumar ◽  
Huey Chong Kwong ◽  
Yip-Foo Win ◽  
Siau Hui Mah ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Molecular Structures ◽  
Steric Repulsion ◽  
Two Dimensional ◽  
Compound I ◽  
Intermolecular Hydrogen Bonds ◽  
Π Interactions ◽  
Phenyl Rings ◽  
Compound Ii

2-(Benzofuran-2-yl)-2-oxoethyl 2-chlorobenzoate, C17H11ClO4 (I), and 2-(benzofuran-2-yl)-2-oxoethyl 2-methoxybenzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and molecular structures were analyzed by spectroscopic and single-crystal X-ray diffraction studies, respectively. These compounds possess different ortho-substituted functional groups on their phenyl rings, thus experiencing extra steric repulsion force within their molecules as the substituent changes from 2-chloro (I) to 2-methoxy (II). The crystal packing of compound (I) depends on weak intermolecular hydrogen bonds and π–π interactions. Molecules are related by inversion into centrosymmetric dimers via C—H...O hydrogen bonds, and further strengthened by π–π interactions between furan rings. Conversely, molecules in compound (II) are linked into alternating dimeric chains propagating along the [101] direction, which develop into a two-dimensional plate through extensive intermolecular hydrogen bonds. These plates are further stabilized by π–π and C—H...π interactions.

scholarly journals Crystal structures and conformational analyses of three pyranochromene derivatives

2015 ◽  
Vol 71 (8) ◽  
pp. 926-930 ◽  
Author(s):  
K. Swaminathan ◽  
K. Sethusankar ◽  
G. Siva Kumar ◽  
M. Bakthadoss
Keyword(s):  
Crystal Structures ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Side Chain ◽  
Compound I ◽  
The Mean ◽  
Compound Ii ◽  
Short Contacts ◽  
Coumarin Ring ◽  
Chromene Ring

The title compounds, C27H20O6, (I) [systematic name: methyl 7-oxo-14-phenyl-1H,7H,14H-pyrano[3,2-c:5,4-c′]dichromene-14a(6bH)-carboxylate], C24H22O5, (II) [systematic name: methyl 1-oxo-6-phenyl-2,3,4,12b-tetrahydro-1H,6H-chromeno[3,4-c]chromene-6a(7H)-carboxylate], and C25H23N3O4, (III) [systematic name: 6-(4-ethylphenyl)-2,4-dimethyl-1,3-dioxo-2,3,4,12b-tetrahydro-1H,6H-chromeno[4′,3′:4,5]pyrano[2,3-d]pyrimidine-6a(7H)-carbonitrile], are pyranochromene derivatives. The central pyran rings (B) of compounds (I) and (III) adopt half-chair conformations, whereas that of compound (II) adopts a sofa conformation. The pyran rings (A) of the chromene ring systems of compounds (II) and (III) adopt half-chair conformations, while that of compound (I) adopts a sofa conformation. The mean plane of the central pyran rings (B) make dihedral angles of 70.02 (6), 61.52 (6) and 69.12 (7)°, respectively, with the mean planes of the chromene moieties (C+A) of compounds (I), (II) and (III). The bicyclic coumarin ring system (C+A+B+E) in compound (I) is almost planar (r.m.s. deviation = 0.042 Å). The carbonitrile side chain in compound (III) is very nearly linear, with the C—C[triple-bond]N angle being 176.6 (2)°. The cyclohexene ring (E), fused with the central pyran ring (B) in compound (II) adopts a sofa conformation. In the molecular structures of compounds (II) and (III), there are C—H...O short contacts, which generateS(7) ring motifs. In the crystal structures of the title compounds, molecules are linked by C—H...O hydrogen bonds, which generate molecular sheets parallel to theabplane, withR43(28) loops in (I), inversion dimers withR22(10) loops in (II) and chains along [010] withR22(12) ring motifs in (III). In the crystal structures of (I) and (III), there are also C—H...π interactions present, leading to the formation of a three-dimensional framework in (II) and to sheets parallel to (101) in (III).

scholarly journals Crystal structures of two new carbazole derivatives: 12-(4-nitrophenyl)-7-phenylsulfonyl-7H-benzofuro[2,3-b]carbazole and 2-methyl-4-(4-nitrophenyl)-9-phenylsulfonyl-9H-thieno[2,3-b]carbazole

2016 ◽  
Vol 72 (12) ◽  
pp. 1739-1743
Author(s):  
K. Swaminathan ◽  
P. Narayanan ◽  
K. Sethusankar ◽  
Velu Saravanan ◽  
Arasambattu K. Mohanakrishnan
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Ring System ◽  
Molecular Structures ◽  
Dihedral Angles ◽  
Compound I ◽  
Carbazole Derivatives ◽  
Phenyl Rings ◽  
The Mean ◽  
Compound Ii

The title compounds, C30H18N2O5S, (I), and C27H18N2O4S2, (II), are carbazole derivatives with a phenylsulfonyl group and a nitrophenyl group attached to the carbazole moiety in identical positions in both molecules. A benzofuran ring system in (I) and a methylthiophene ring in (II) are fused with the respective carbazole moieties on the same sides. The mean plane of the carbazole ring system makes a dihedral angle of 3.17 (7)° with the benzofuran ring system in (I) and a dihedral angle of 3.39 (11)° with the methylthiophene ring in (II), implying that both fused units are essentially planar. The mean planes of the carbazole ring systems in both the compounds are almost orthogonal to the respective nitro-substituted phenyl rings, making dihedral angles of 75.64 (10) and 77.63 (12)° in compounds (I) and (II), respectively. In (I), the phenylsulfonyl ring system is positionally disordered with a refined occupancy ratio of 0.63 (2):0.37 (2). In both compounds, the molecular structures are stabilized by intramolecular C—H...O hydrogen bonds, generatingS(6) ring motifs with the sulfone group O atoms. In the crystal of compound (I), molecules are linked by pairs of C—H...O hydrogen bonds, which generateR22(18) inversion dimers, and interconnected byC(14) chains running along thec-axis direction, whereas in compound (II), the C—H...O hydrogen bonds generateR43(37) ring motifs. In the crystals of both compounds, C—H...O hydrogen-bonded sheets are formed lying parallel to (10-1). In addition, C—H...π and offset π–π interactions [intercentroid distance = 3.7158 (14) Å in (I) and 3.9040 (15) Å in (II)] are also present in the crystals of both compounds.

scholarly journals Crystal structures ofN-[(4-phenylthiazol-2-yl)carbamothioyl]benzamide andN-{[4-(4-bromophenyl)thiazol-2-yl]carbamothioyl}benzamide from synchrotron X-ray diffraction

2016 ◽  
Vol 72 (9) ◽  
pp. 1343-1347 ◽  
Author(s):  
Ekaterina S. Gantimurova ◽  
Alexander S. Bunev ◽  
Kristina Yu. Talina ◽  
Gennady I. Ostapenko ◽  
Pavel V. Dorovatovskii ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Dihedral Angles ◽  
Active Pharmaceutical Ingredients ◽  
X Ray Diffraction ◽  
Compound I ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Phenyl Rings ◽  
Compound Ii

The title compounds, C17H13N3OS2, (I), and C17H12BrN3OS2, (II), are potential active pharmaceutical ingredients. Compound (I) comprises two almost planar fragments. The first is the central (carbamothioyl)amide (r.m.s. deviation = 0.038 Å), and the second consists of the thiazole and two phenyl rings (r.m.s. deviation = 0.053 Å). The dihedral angle between these planes is 15.17 (5)°. Unlike (I), compound (II) comprises three almost planar fragments. The first is the centralN-(thiazol-2-ylcarbamothioyl)amide (r.m.s. deviation = 0.084 Å), and the two others comprise the bromophenyl and phenyl substituents, respectively. The dihedral angles between the central and two terminal planar fragments are 21.58 (7) and 17.90 (9)°, respectively. Both (I) and (II) feature an intramolecular N—H...O hydrogen bond, which closes anS(6) ring. In the crystal of (I), molecules form hydrogen-bonded layers parallel to (100) mediated by N—H...S and C—H...O hydrogen bonds. In the crystal of (II), molecules form a three-dimensional framework mediated by N—H...Br and C—H...O hydrogen bonds, as well as secondary S...Br [3.3507 (11) Å] and S...S [3.4343 (14) Å] interactions.

scholarly journals Isotypic crystal structures of 2,6-dibromo-N,N-bis(4-nitrophenyl)aniline and 2,6-dichloro-N,N-bis(4-nitrophenyl)aniline

2014 ◽  
Vol 70 (8) ◽  
pp. 65-67 ◽  
Author(s):  
Paul Kautny ◽  
Johannes Fröhlich ◽  
Berthold Stöger ◽  
Matthias Weil
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Van Der Waals ◽  
Three Dimensional ◽  
Compound I ◽  
Dimensional Network ◽  
Phenyl Rings ◽  
The Mean ◽  
Compound Ii ◽  
Van Der Waals Radii

In the molecules of the two isotypic title compounds, C18H11Br2N3O4(I) and C18H11Cl2N3O4(II), the triphenylamine N atoms show no sign of pyramidalization, with marginal displacements of the N atoms from the mean plane of the three connecting C atoms: 0.0058 (13) Å for the Br compound (I) and 0.0074 (9) Å for the Cl compound (II). In the crystals, molecules are linked through C—H...O hydrogen bonds between phenyl rings and nitro groups and byX...O (X= Br, Cl) interactions, that are shorter than the sum of the van der Waals radii, leading to a three-dimensional network.

scholarly journals Crystal structures of {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}nand {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n[where Lpn = (R)-propane-1,2-diamine]: two heterometallic chiral cyanide-bridged coordination polymers

2015 ◽  
Vol 71 (4) ◽  
pp. 392-397
Author(s):  
Olha Sereda ◽  
Helen Stoeckli-Evans
Keyword(s):  
Hydrogen Bonds ◽  
Coordination Polymers ◽  
Three Dimensional ◽  
Water Molecules ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Compound I ◽  
Distorted Octahedral ◽  
Coordination Spheres ◽  
Compound Ii

The title compounds,catena-poly[[[bis[(R)-propane-1,2-diamine-κ2N,N′]copper(II)]-μ-cyanido-κ2N:C-[tris(cyanido-κC)(nitroso-κN)iron(III)]-μ-cyanido-κ2C:N] monohydrate], {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O}n, (I), and poly[[hexa-μ-cyanido-κ12C:N-hexacyanido-κ6C-hexakis[(R)-propane-1,2-diamine-κ2N,N′]dichromium(III)tricopper(II)] pentahydrate], {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O}n, (II) [where Lpn = (R)-propane-1,2-diamine, C3H10N2], are new chiral cyanide-bridged bimetallic coordination polymers. The asymmetric unit of compound (I) is composed of two independent cation–anion units of {[Cu(Lpn)2][Fe(CN)5)(NO)]} and two water molecules. The FeIIIatoms have distorted octahedral geometries, while the CuIIatoms can be considered to be pentacoordinate. In the crystal, however, the units align to form zigzag cyanide-bridged chains propagating along [101]. Hence, the CuIIatoms have distorted octahedral coordination spheres with extremely long semicoordination Cu—N(cyanido) bridging bonds. The chains are linked by O—H...N and N—H...N hydrogen bonds, forming two-dimensional networks parallel to (010), and the networks are linkedviaN—H...O and N—H...N hydrogen bonds, forming a three-dimensional framework. Compound (II) is a two-dimensional cyanide-bridged coordination polymer. The asymmetric unit is composed of two chiral {[Cu(Lpn)2][Cr(CN)6]}−anions bridged by a chiral [Cu(Lpn)2]2+cation and five water molecules of crystallization. Both the CrIIIatoms and the central CuIIatom have distorted octahedral geometries. The coordination spheres of the outer CuIIatoms of the asymmetric unit can be considered to be pentacoordinate. In the crystal, these units are bridged by long semicoordination Cu—N(cyanide) bridging bonds forming a two-dimensional network, hence these CuIIatoms now have distorted octahedral geometries. The networks, which lie parallel to (10-1), are linkedviaO—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds involving all five non-coordinating water molecules, the cyanide N atoms and the NH2groups of the Lpn ligands, forming a three-dimensional framework.

scholarly journals Some chalcones derived from thiophene-3-carbaldehyde: synthesis and crystal structures

2019 ◽  
Vol 75 (7) ◽  
pp. 957-963 ◽  
Author(s):  
Trung Vu Quoc ◽  
Duong Tran Thi Thuy ◽  
Thuan Dang Thanh ◽  
Thanh Phung Ngoc ◽  
Vuong Nguyen Thien ◽  
...  
Keyword(s):  
Potassium Hydroxide ◽  
Thiophene Ring ◽  
Three Dimensional ◽  
Ethanol Solution ◽  
Molecular Structures ◽  
Chain Formation ◽  
Axis Direction ◽  
Crystal And Molecular Structures ◽  
Phenyl Rings ◽  
Thiophene Derivatives

The synthesis, spectroscopic data and crystal and molecular structures of four 3-(3-phenylprop-1-ene-3-one-1-yl)thiophene derivatives, namely 1-(4-hydroxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H10O2S, (1), 1-(4-methoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C14H12O2S, (2), 1-(4-ethoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C15H14O2S, (3), and 1-(4-bromophenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H9BrOS, (4), are described. The four chalcones have been synthesized by reaction of thiophene-3-carbaldehyde with an acetophenone derivative in an absolute ethanol solution containing potassium hydroxide, and differ in the substituent at the para position of the phenyl ring: –OH for 1, –OCH3 for 2, –OCH2CH3 for 3 and –Br for 4. The thiophene ring in 4 was found to be disordered over two orientations with occupancies 0.702 (4) and 0.298 (4). The configuration about the C=C bond is E. The thiophene and phenyl rings are inclined by 4.73 (12) for 1, 12.36 (11) for 2, 17.44 (11) for 3 and 46.1 (6) and 48.6 (6)° for 4, indicating that the –OH derivative is almost planar and the –Br derivative deviates the most from planarity. However, the substituent has no real influence on the bond distances in the α,β-unsaturated carbonyl moiety. The molecular packing of 1 features chain formation in the a-axis direction by O—H...O contacts. In the case of 2 and 3, the packing is characterized by dimer formation through C—H...O interactions. In addition, C—H...π(thiophene) interactions in 2 and C—H...S(thiophene) interactions in 3 contribute to the three-dimensional architecture. The presence of C—H...π(thiophene) contacts in the crystal of 4 results in chain formation in the c-axis direction. The Hirshfeld surface analysis shows that for all four derivatives, the highest contribution to surface contacts arises from contacts in which H atoms are involved.

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