Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl benzoate.

The title com-pound, C15H11NO5, is relatively planar, with the planes of the two aromatic rings being inclined to each other by 3.09 (5)°. In the crystal, mol-ecules are linked by a pair of C-H⋯O hydrogen bonds, forming inversion dimers, which enclose an R 2 2(16) ring motif. The dimers are linked by a further pair of C-H⋯O hydrogen-bonds forming ribbons enclosing R 4 4(26) ring motifs. The ribbons are linked by offset π-π inter-actions [centroid-centroid distances = 3.6754 (6)-3.7519 (6) Å] to form layers parallel to the ac plane. Through Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecule are involved with the same contacts in neighbouring mol-ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl picolinate.

2-(4-Nitro-phen-yl)-2-oxoethyl picolinate, C14H10N2O5, was synthesized under mild conditions. The chemical and mol-ecular structures were confirmed by single-crystal X-ray diffraction analysis. The mol-ecules are linked by inversion into centrosymmetric dimers via weak inter-molecular C-H⋯O inter-actions, forming R 2 2(10) ring motifs, and further strengthened by weak π-π inter-actions. Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint (FP) plots were used to verify the contributions of the different inter-molecular inter-actions within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecules are involved with the same contacts in neighbouring mol-ecules and curvedness plots show flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of 2-(4-nitro-phen-yl)-2-oxoethyl 2-chloro-benzoate.

The title compound, C15H10ClNO5, is relatively planar with the two aromatic rings being inclined to each other by 3.56 (11)°. The central -C(=O)-C-O-C(=O)- bridge is slightly twisted, with a C-C-O-C torsion angle of 164.95 (16)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯Cl hydrogen bonds, forming layers parallel to the (101) plane. The layers are linked by a further C-H⋯O hydrogen bond, forming a three-dimensional supra-molecular structure. There are a number of offset π-π inter-actions present between the layers [inter-centroid distances vary from 3.8264 (15) to 3.9775 (14) Å]. Hirshfeld surface analyses, the d norm surfaces, electrostatic potential and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The shape-index surface shows that two sides of the mol-ecule are involved in the same contacts with neighbouring mol-ecules, and the curvedness plot shows flat surface patches that are characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of (2E)-3-(4-chloro-3-fluoro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

The mol-ecular structure of the title compound, C17H14ClFO3, consists of a 4-chloro-3-fluoro-phenyl ring and a 3,4-di-meth-oxy-phenyl ring linked via a prop-2-en-1-one spacer. The mol-ecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. The F and H atoms at the meta positions of the 4-chloro-3-fluoro-phenyl ring are disordered over two orientations, with an occupancy ratio of 0.785 (3):0.215 (3). In the crystal, mol-ecules are linked via pairs of C-H⋯O inter-actions with an R 2 2(14) ring motif, forming inversion dimers. The dimers are linked into a tape structure running along [10] by a C-H⋯π inter-action. The inter-molecular contacts in the crystal were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are H⋯H (25.0%), followed by C⋯H/H⋯C (20.6%), O⋯H/H⋯O (15.6%), Cl⋯H/H⋯Cl (10.7%), F⋯H/H⋯F (10.4%), F⋯C/C⋯F (7.2%) and C⋯C (3.0%).

Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one.

The mol-ecular structure of the title compound, C13H7Cl3OS, consists of a 2,5- di-chloro-thio-phene ring and a 2-chloro-phenyl ring linked via a prop-2-en-1-one spacer. The dihedral angle between the 2,5-di-chloro-thio-phene and 2-chloro-phenyl rings is 9.69 (12)°. The mol-ecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. The mol-ecular conformation is stabilized by two intra-molecular C-H⋯Cl contacts and one intra-molecular C-H⋯O contact, forming S(5)S(5)S(6) ring motifs. In the crystal, the mol-ecules are linked along the a-axis direction through van der Waals forces and along the b axis by face-to-face π-stacking between the thio-phene rings and between the benzene rings of neighbouring mol-ecules, forming corrugated sheets lying parallel to the bc plane. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are Cl⋯H/ H⋯Cl (28.6%), followed by C⋯H/H⋯C (11.9%), C⋯C (11.1%), H⋯H (11.0%), Cl⋯Cl (8.1%), O⋯H/H⋯O (8.0%) and S⋯H/H⋯S (6.6%).

Crystal structure and Hirshfeld surface analysis of (2E)-1-(3-bromo-phen-yl)-3-(4-fluoro-phen-yl)prop-2-en-1-one.

In the title compound, C15H10BrFO, the mol-ecular structure consists of a 3-bromo-phenyl ring and a 4-fluoro-phenyl ring linked via a prop-2-en-1-one spacer. The 3-bromophenyl and 4-fluorophenyl rings make a dihedral angle of 48.90 (15)°. The mol-ecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. In the crystal, mol-ecules are linked by C-H⋯π inter-actions between the bromo-phenyl and fluoro-phenyl rings of mol-ecules, resulting in a two-dimensional layered structure parallel to the ab plane. The mol-ecular packing is stabilized by weak Br⋯H and F⋯H contacts, one of which is on the one side of each layer, and the second is on the other. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfeld surface analysis, which indicates that the most significant contacts are Cl⋯H/H⋯Cl (20.8%), followed by C⋯H/H⋯C (31.1%), H⋯H (21.7%), Br⋯H/H⋯Br (14.2%), F⋯H/H⋯F (9.8%), O⋯H/H⋯O (9.7%).

Crystal structure and Hirshfeld surface analysis of a bromo-chalcone: (E)-1-(3-bromo-phen-yl)-3-(2,6-di-chloro-phen-yl)prop-2-en-1-one.

In the title chalcone derivative, C15H9BrCl2O, the aryl rings are inclined to each by 14.49 (17)°, and the configuration about the C=C bond is E. There is a short intra-molecular C-H⋯Cl contact present resulting in the formation of an S(6) ring motif. In the crystal, the shortest inter-molecular contacts are Cl⋯O contacts [3.173 (3) Å] that link the mol-ecules to form a 21 helix propagating along the b-axis direction. The helices stack up the short crystallographic a axis, and are linked by offset π-π inter-actions [inter-centroid distance = 3.983 (1) Å], forming layers lying parallel to the ab plane. A qu-anti-fication of the inter-molecular contacts in the crystal were estimated using Hirshfeld surface analysis and two-dimensional fingerprint plots.

Crystal Correlation Of Heterocyclic Imidazo[1,2-a]pyridine Analogues and Their Anticholinesterase Potential Evaluation.

Imidazo[1,2-a]pyridine-based compounds are clinically important to the treatments of heart and circulatory failures, while many are under development for pharmaceutical uses. In this study, a series of imidazo[1,2-a]pyridine-based derivatives 2(a-o) were synthesized by reacting a-haloketones with 2-aminopyridines in a basic media at ambient temperature. Single crystal X-ray diffraction studies suggest that with low degree-of-freedom, the introduction of bulky adamantyl or electron-rich biphenyl moiety into the imidazopyridine derivatives will not affect its structural occupancy. Imidazo[1,2-a]pyridine-based derivatives with biphenyl side chain are potential AChE inhibitors. Compound 2h which bears a biphenyl side chain and methyl substituent at the position R4 of the imidazo[1,2-a]pyridine ring showed the strongest AChE inhibition with an IC50 value of 79 µM. However, imidazo[1,2-a]pyridine derivatives with phenyl side chain exhibit better BChE inhibition effect among the series. Compound 2j with 3,4-dichlorophenyl side chain and unsubstituted imidazo[1,2-a]pyridine ring appears to be the strongest BChE inhibitor with an IC50 value of 65 µM and good selectivity. The inhibitory effects of active compounds were further confirmed by computational molecular docking studies. The results unveiled that peripheral anionic sites of AChE and acyl pocket of BChE were the predominated binding sites for the subjected inhibitors.

Conformational dimorphism of 2,2'-methyl-enebis(isoindoline-1,3-dione).

In this study, a new monoclinic polymorph (space group C2/c) of 2,2'-methyl-enebis(isoindoline-1,3-dione), C17H10N2O4, is reported and compared to the previously reported triclinic polymorph (space group P ). Similarly, both polymorphs consist of a unique mol-ecule in the asymmetric unit (Z' = 1). The mol-ecular conformations of the two polymorphs are very similar, as shown by the r.m.s. deviation of 0.368 Š(excluding all H atoms). The inter-molecular inter-actions of both polymorphs are described along with the Hirshfeld surface analysis, and the lattice energies are calculated.

Crystal structure and Hirshfeld surface analysis of a chalcone derivative: (E)-3-(4-fluoro-phen-yl)-1-(4-nitro-phen-yl)prop-2-en-1-one.

The mol-ecular structure of the title chalcone derivative, C15H10FNO3, is nearly planar and the mol-ecule adopts a trans configuration with respect to the C=C double bond. The nitro group is nearly coplanar with the attached benzene ring, which is nearly parallel to the second benzene ring. In the crystal, mol-ecules are connected by pairs of weak inter-molecular C-H⋯O hydrogen bonds into inversion dimers. The dimers are further linked by another C-H⋯O hydrogen bond and a C-H⋯F hydrogen bond into sheets parallel to (104). π-π inter-actions occur between the sheets, with a centroid-centroid distance of 3.8860 (11) Å. Hirshfeld surface analysis was used to investigate and qu-antify the inter-molecular inter-actions.

Crystal structure and Hirshfeld surface analysis of (2E)-3-(2,4-di-chloro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one.

The mol-ecular structure of the title compound, C13H6Cl4OS, consists of a 2,5-di-chloro-thio-phene ring and a 2,4-di-chloro-phenyl ring linked via a prop-2-en-1-one spacer. The dihedral angle between the 2,5-di-chloro-thio-phene ring and the 2,4-di-chloro-phenyl ring is 12.24 (15)°. The mol-ecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. The mol-ecular conformation is stabilized by intra-molecular C-H⋯Cl contacts, producing S(6) and S(5) ring motifs. In the crystal, the mol-ecules are linked along the a-axis direction through face-to-face π-stacking between the thio-phene rings and the benzene rings of the mol-ecules in zigzag sheets lying parallel to the bc plane along the c axis. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are Cl⋯H/ H⋯Cl (20.8%), followed by Cl⋯Cl (18.7%), C⋯C (11.9%), Cl⋯S/S⋯Cl (10.9%), H⋯H (10.1%), C⋯H/H⋯C (9.3%) and O⋯H/H⋯O (7.6%).

Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-bromo-4-fluoro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

In the mol-ecule of the title compound, C17H14BrFO3, the aromatic rings are tilted with respect to the enone bridge by 13.63 (14) and 4.27 (15)°, and form a dihedral angle 17.91 (17)°. In the crystal, centrosymmetrically related mol-ecules are linked by pairs of C-H⋯O hydrogen bonds into dimeric units, forming rings of R22(14) graph-set motif. The dimers are further connected by weak C-H⋯O hydrogen inter-actions, forming layers parallel to (10). Hirshfeld surface analysis shows that van der Waals inter-actions constitute the major contribution to the inter-molecular inter-actions, with H⋯H contacts accounting for 29.7% of the surface.

Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-4-fluoro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one.

In the title chalcone-thio-phene derivative, C13H6Cl3FOS, the aromatic rings are inclined to one another by 12.9 (2)°, and the thio-phene ring is affected by π-conjugation. In the crystal, mol-ecules are linked by C-H⋯F hydrogen bonds, forming an R22(8) ring motif. A Hirshfeld surface analysis was conducted to verify the contribution of the different inter-molecular inter-actions. The shape-index surface clearly shows that the two sides of the mol-ecules are involved in the same contacts with neighbouring mol-ecules and the curvedness plots show flat surface patches characteristic of planar stacking.

Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-chloro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one.

In title compound, C17H15ClO3, the dihedral angle between the benzene and chloro-phenyl rings is 18.46 (7)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen contacts, enclosing an R22(14) ring motif, and by a further C-H⋯O hydrogen contact, forming a two-dimensional supra-molecular structure extending along the direction parallel to the ac plane. Hirshfeld surface analysis shows that van der Waals inter-actions constitute the major contribution to the inter-molecular inter-actions, with H⋯H contacts accounting for 36.2% of the surface.

Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-(adamantan-1-yl)-2-oxoeth-yl]pyridin-4-iminium bromide.

In the cation of the title salt, C17H23N2O+·Br-, the adamantyl moiety and the pyridiniminium ring are inclined to the ketone bridge by torsion angles of -78.1 (2) (C-C-C=O) and 58.3 (2)° (C-C-N-C), respectively, and the ketone bridge has a C-C-C-N torsion angle of 174.80 (15)°. In the crystal, the cations are connected into chains parallel to the c axis by C-H⋯O hydrogen bonds. The chains are further linked into layers parallel to the bc plane by N-H⋯Br and C-H⋯Br hydrogen bonds, C-H⋯π inter-actions and π-π stacking inter-actions [centroid-to-centroid distance = 3.5657 (11) Å]. A Hirshfeld surface analysis, which comprises the dnorm surface, electrostatic potential map and two-dimensional fingerprint plots, was carried out to verify the contribution of the various inter-molecular inter-actions.

Synthesis, spectroscopic and Hirshfeld surface analysis and fluorescence studies of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(4-hy-droxy-phen-yl)prop-2-en-1-one] N,N-di-methyl-formamide disolvate.

In the bis-chalcone mol-ecule of the title compound, C24H18O4·2C3H7NO, the central benzene and terminal hy-droxy-phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis-chalcone and solvate mol-ecules are inter-connected via O-H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (Ff) is 0.18.

Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-([1,1'-biphen-yl]-4-yl)-2-oxoeth-yl]-3-methyl-1,4-di-hydro-pyridin-4-iminium bromide.

In the cation of the title salt, C20H19N2O+·Br-, the phenyl rings are inclined to one another by 38.38 (8)°, whereas the central phenyl ring and the pyridiniminium ring are almost perpendicular with a dihedral angle of 87.37 (9)°. The N+=C cationic double bond was verified by the shortened bond length of 1.337 (2) Å. In the crystal, the Br- anion is linked to the cation by an N-H⋯Br hydrogen bond. C-H⋯O hydrogen bonds link adjacent pyridiniminium cations into inversion dimers with an R22(18) graph-set motif. These dimers are stacked in a phen-yl-phenyl T-shaped geometry through C-H⋯π inter-actions. A Hirshfeld surface analysis was conducted to verify the contributions of the different inter-molecular inter-actions.

Crystal structure and Hirshfeld surface analysis of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(2,4-di-fluoro-phen-yl)prop-2-en-1-one].

The asymmetric unit of the title compound, C24H14F4O2, comprises of one and a half mol-ecules; the half-mol-ecule is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯F and C-H⋯O hydrogen bonds. Some of the C-H⋯F links are unusually short (< 2.20 Å). Hirshfeld surface analyses (dnorm surfaces and two-dimensional fingerprint plots) for the title compound are presented and discussed.

Steric repulsion and supra-molecular assemblies via a two-dimensional plate by C-H⋯O hydrogen bonds in two closely related 2-(benzo-furan-2-yl)-2-oxoethyl benzoates.

2-(Benzo-furan-2-yl)-2-oxoethyl 2-chloro-benzoate, C17H11ClO4 (I), and 2-(benzo-furan-2-yl)-2-oxoethyl 2-meth-oxy-benzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and mol-ecular 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 mol-ecules as the substituent changes from 2-chloro (I) to 2-meth-oxy (II). The crystal packing of compound (I) depends on weak inter-molecular hydrogen bonds and π-π inter-actions. Mol-ecules are related by inversion into centrosymmetric dimers via C-H⋯O hydrogen bonds, and further strengthened by π-π inter-actions between furan rings. Conversely, mol-ecules in compound (II) are linked into alternating dimeric chains propagating along the [101] direction, which develop into a two-dimensional plate through extensive inter-molecular hydrogen bonds. These plates are further stabilized by π-π and C-H⋯π inter-actions.

The crystal structure of zwitterionic 2-{[(4-imin-iumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate hemihydrate.

The asymmetric unit of the title compound, C15H15N3O3·0.5H2O, comprises two 2-{[(4-iminiumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate zwitterions (A and B) and a water mol-ecule. The dihedral angles between the pyridine and phenyl rings in the zwitterions are 53.69 (10) and 73.56 (11)° in A and B, respectively. In the crystal, mol-ecules are linked by N-H⋯O, O-H⋯O, C-H⋯O and C-H⋯π(ring) hydrogen bonds into a three-dimensional network. The crystal structure also features π-π inter-actions involving the centroids of the pyridine and phenyl rings [centroid-centroid distances = 3.5618 (12) Šin A and 3.8182 (14) Šin B].