Crystal structures of 2-methyl-pyridinium hydrogen 2,3-bis-(4-methyl-benzo-yloxy)succinate and bis-[4-methyl-pyridinium hydrogen 2,3-bis-(4-methyl-benzo-yloxy)succinate] penta-hydrate.

The title salt (I), C6H8N+·C20H17O8-, comprises a 2-methyl-pyridinium cation and a 2,3-bis-(4-methyl-benzo-yloxy)succinate mono-anion while the salt (II), 2C6H8N+·2C20H17O8-·5H2O, consists of a pair of 4-methyl-pyridinium cations and 2,3-bis-(4-methyl-benzo-yloxy)succinate mono-anions and five water mol-ecules of solvation in the asymmetric unit. In (I), the dihedral angle between the aromatic rings of the anion is 40.41 (15)°, comparing with 43.0 (3) and 85.7 (2)° in the conformationally dissimilar anion mol-ecules in (II). The pyridine ring of the cation in (I) is inclined at 23.64 (16) and 42.69 (17)° to the two benzene moieties of the anion. In (II), these comparative values are 4.7 (3), 43.5 (3)° and 43.5 (3), 73.1 (3)° for the two associated cation and anion pairs. The crystal packing of (I) is stabilized by inter-ionic N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds as well as weak C-H⋯π inter-actions, linking the ions into infinite chains along [100]. In the crystal packing of (II), the anions and cations are also linked by N-H⋯O and O-H⋯O hydrogen bonds involving also the water mol-ecules, giving a two-dimensional network across (001). The crystal structure is also stabilized by weak C-H⋯O and C-H⋯π inter-actions.

Cobalt(III) complexes as potential anticancer agents: Physicochemical, structural, cytotoxic activity and DNA/protein interactions.

Cobalt(III) complexes (1-3) such as [Co(acac)(bpy)(N3)2·H2O] 1, [Co(acac)(en)(N3)2] 2, and [Co(acac)(2-pic)(N3)2] 3 (where, acac=acetylacetone, bpy=2.2'-bipyridine, en=ethylenediamine, 2-pic=2-picolylamine and NaN3=sodium azide) were synthesized and characterized. The structure of complexes (1-3) has been determined by single crystal X-ray diffraction studies and the configuration around cobalt(III) ion was distorted octahedral coordination geometry. Density functional theory calculations were performed to examine the molecular geometry and frontier molecular orbital properties of complexes (1-3). DNA binding properties of the cobalt(III) complexes with calf thymus DNA (CT-DNA) were investigated by UV-visible absorption, fluorescence, circular dichroism spectroscopy and viscosity measurements. The docking studies showed the preferred orientation of sterically acceptable Co(III) complexes (1, 2) inside the DNA through the mode of intercalation, whereas complex 3 exhibited minor groove binding modes. The intrinsic binding constants Kb of complexes (1-3) with CT-DNA were in the following order 1>3>2. Complexes (1-3) exhibit a good binding propensity to bovine serum albumin (BSA) and gel electrophoresis assay demonstrated that the complexes (1-3) promote the cleavage of the pBR322 DNA in the presence of 3-mercaptopropionic acid (MPA) and cleavage process was found to proceed by singlet oxygen cleavage mechanism. Further, the in vitro cytotoxicity studies of complexes (1-3) were tested on human breast cancer cell line (MCF-7).

Synthesis, interactions, molecular structure, biological properties and molecular docking studies on Mn, Co, Zn complexes containing acetylacetone and pyridine ligands with DNA duplex.

Three metal complexes (1-3) of the type [Mn(acac)2(py)·H2O] (1), [Co(acac)2(py)·H2O] (2) and [Zn(acac)2(py)·H2O] (3), [Where acac=acetylacetone, py=pyridine] were synthesized and characterized by spectral (UV-vis, FT-IR, ESI-mass) analysis. The structure of complex 2 has been determined by single crystal X-ray diffraction studies and the configuration of ligand-coordinated to metal(II) ion was well described as distorted octahedral coordination geometry. The interaction of the complexes with CT-DNA has been explored by absorption, fluorescence, circular dichromism spectroscopy, viscosity measurements and molecular docking studies. The intrinsic binding constant Kb of complexes 1-3 with CT-DNA obtained from UV-vis absorption spectral studies were 2.1×10(4), 2.1×10(5) and 1.98×10(4)M(-1), respectively, which revealed that the complexes could interact with CT-DNA through groove binding. The results indicated that the complexes (1-3) were able to bind to DNA with different binding affinity, in the order: 2>1>3. The interaction of the compounds with bovine serum albumins were also investigated using fluorescence methods and the gel electrophoresis assay demonstrates weak cleavage ability of the pBR322 plasmid DNA in the presence of the metal complexes (1-3) with various activators. Further, the in vitro cytotoxic effect of the complexes were examined on cancerous cell line, with human breast cancer cells MCF-7.

Crystal structure of 5-di-ethyl-amino-2-({[4-(di-ethyl-amino)-phen-yl]imino}-meth-yl)phenol.

In the title compound, C21H29N3O, the dihedral angle between the planes of the aromatic rings is 8.1 (2)°. The ethyl groups at one terminal site of the compound are disordered over two sets of sites with occupancies of 0.775 (9) and 0.225 (9). The mol-ecule has an E conformation about the N=C bond. The mol-ecular structure features an intra-molecular O-H⋯N hydrogen bond, which closes an S(6) loop. In the crystal, weak C-H⋯π inter-actions leads to the formation of a three-dimensional network.

Crystal structure of (E)-2-(4-meth-oxy-styr-yl)-3-methyl-1-phenyl-sulfonyl-1H-indole.

In the title compound, C24H21NO3S, the dihedral angles between the indole ring system (r.m.s. deviation = 0.030 Å) and the sulfur and ethyl-ene-bonded benzene rings are 80.2 (2) and 49.29 (15)°, respectively. The dihedral angle between the pendant benzene rings is 37.7 (2)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds and weak C-H⋯π and π-π [centroid-to-centroid distances = 3.549 (2) and 3.743 (3) Å] inter-actions, forming a three-dimensional network.

Crystal structure of ethyl 2-phenyl-9-phenyl-sulfonyl-9H-carbazole-3-carboxyl-ate.

In the title compound, C27H21NO4S, the dihedral angles between the carbazole ring system (r.m.s. deviation = 0.015 Å) and the sulfur-bonded and directly linked benzene rings are 79.98 (11) and 53.51 (18)°, respectively. The benzene rings subtend a dihedral angle of 48.4 (2)°. The ethyl side chain of the ester group has an extended conformation [C-O-C-C = -172.3 (3)°]. In the crystal, inversion dimers linked by pairs of weak C-H⋯O hydrogen bonds generate R 2 (2)(22) loops. The dimers are linked by weak C-H⋯π and π-π [centroid-to-centroid distances ranging from 3.5042 (14) to 3.888 (2) Å] inter-actions, thereby forming a three-dimensional supra-molecular network.

Crystal structure of N-{[3-bromo-1-(phenyl-sulfon-yl)-1H-indol-2-yl]meth-yl}benzene-sulfonamide.

In the title compound, C21H17BrN2O4S2, the indole ring system subtends dihedral angles of 85.96 (13) and 9.62 (16)° with the planes of the N- and C-bonded benzene rings, respectively. The dihedral angles between the benzene rings is 88.05 (17)°. The mol-ecular conformation is stabilized by intra-molecular N-H⋯O and C-H⋯O hydrogen bonds and an aromatic π-π stacking [centroid-to-centroid distance = 3.503 (2) Å] inter-action. In the crystal, short Br⋯O [2.9888 (18) Å] contacts link the mol-ecules into [010] chains. The chains are cross-linked by weak C-H⋯π inter-actions, forming a three-dimensional network.

Crystal structure of benzimidazolium salicylate.

In the anion of the title mol-ecular salt, C7H7N2 (+)·C7H5O3 (-) (systematic name: 1H-benzimidazol-3-ium 2-hy-droxy-ben-zo-ate), there is an intra-molecular O-H⋯O hydrogen bond that generates an S(6) ring motif. The CO2 group makes a dihedral angle of 5.33 (15)° with its attached ring. In the crystal, the dihedral angle between the benzimidazolium ring and the anion benzene ring is 75.88 (5)°. Two cations bridge two anions via two pairs of N-H⋯O hydrogen bonds, enclosing an R (4) 4(16) ring motif, forming a four-membered centrosymmetric arrangement. These units are linked via C-H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked by C-H⋯π and π-π inter-actions [inter-centroid distances = 3.4156 (7) and 3.8196 (8) Å], forming a three-dimensional structure.

Crystal structure of 3-(2-nitro-phen-yl)-1-(1-phenyl-sulfonyl-1H-indol-3-yl)propan-1-one.

In the title compound, C23H18N2O5S, the phenyl and benzene rings subtend dihedral angles of 78.18 (10) and 30.18 (9)°, respectively, with the indole ring system (r.m.s. deviation = 0.022 Å). The crystal structure features weak C-H⋯O and C-H⋯π inter-actions, which link the mol-ecules into a three-dimensional network.

Crystal structure of 2-phenyl-ethanaminium 3-carb-oxy-prop-2-enoate.

The title mol-ecular salt, C8H12N(+)·C4H3O4 (-), crystallized with two independent cations and anions in the asymmetric unit. The ethanaminium side chains of the cations exhibit anti conformations [C-C-C-N torsion angles = 176.5 (3) and -179.4 (3)°]. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds connect adjacent anions and cations, and , O-H⋯O hydrogen bonds connect adjacent anions, generating sheets parallel to (001).

Crystal structure of 2,5-di-methyl-anilinium salicylate.

The title mol-ecular salt, C8H12N(+)·C7H5O3 (-) arose from the proton-transfer reaction between 2,5-xylidine and salicylic acid. In the anion, the dihedral angle between the planes of the aromatic ring and the -CO2 (-) group is 11.08 (8)°; this near planarity is consolidated by an intra-molecular O-H⋯O hydrogen bond. In the crystal, the components are connected by N-H⋯O hydrogen bonds, with all three O atoms in the anion acting as acceptors; the result is a [100] chain. The structure also features weak C-H⋯O bonds and aromatic π-π stacking [centroid-to-centroid distance = 3.7416 (10) Å] inter-actions, which lead to a three-dimensional network.

Crystal structure of (E)-5-di-ethyl-amino-2-({[4-(di-methyl-amino)-phen-yl]imino}-meth-yl)phenol.

The title Schiff base compound, C19H25N3O, is approximately planar, with a dihedral angle of 9.03 (13)° between the planes of the aromatic rings, and has an E conformation about the N=C bond. The mol-ecular structure is stabilized by an intra-molecular O-H⋯N hydrogen bond, with an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming sheets parallel to the bc plane.

Crystal structure of 8-hy-droxy-quinolin-ium 2-carboxy-6-nitro-benzoate mono-hydrate.

In the title hydrated salt, C9H8NO(+)·C8H4NO6 (-)·H2O, the deprotonated carboxyl-ate group is almost normal to its attached benzene ring [dihedral angle = 83.56 (8)°], whereas the protonated carboxyl-ate group is close to parallel [dihedral angle = 24.56 (9)°]. In the crystal, the components are linked by N-H⋯O and O-H⋯O hydrogen bonds, generating [001] chains. The packing is consolidated by C-H⋯O and π-π [centroid-to-centroid distances = 3.6408 (9) and 3.6507 (9) Å] inter-actions, which result in a three-dimensional network.

Crystal structure of quinolinium 2-carboxy-6-nitro-benzoate monohydrate.

In the anion of the title hydrated mol-ecular salt, C9H8N(+)·C8H4NO6 (-)·H2O, the protonated carboxyl and nitro groups makes dihedral angles of 27.56 (5) and 6.86 (8)°, respectively, with the attached benzene ring, whereas the deprotonated carb-oxy group is almost orthogonal to it with a dihedral angle of 80.21 (1)°. In the crystal, the components are linked by O-H⋯O and N-H⋯O hydrogen bonds, generating [001] chains. The packing is consolidated by weak C-H⋯N and C-H⋯O inter-actions as well as aromatic π-π stacking [centroid-to-centroid distances: 3.7023 (8) & 3.6590 (9)Å] inter-actions, resulting in a three-dimensional network.

Crystal structure of 4-bromo-anilinium 4-methyl-benzene-sulfonate.

In the crystal of the title mol-ecular salt, C6H7BrN(+)·C7H7O3S(-), the anions and cations are linked via N-H⋯O hydrogen bonds forming layers, enclosing R 2 (2)(4) ring motifs, lying parallel to (001). Within the layers there are short O⋯O contacts of 2.843 (2) Å.

Crystal structure of (2-methyl-1-phenyl-sulfon-yl-1H-indol-3-yl)(phen-yl)methanone.

In the title compound, C22H17NO3S, the sulfonyl-bound phenyl ring is almost orthogonal to the indole ring system, making a dihedral angle of 84.89 (7)°. The carbonyl-bound phenyl ring forms a dihedral angle of 57.32 (5)° with the indole ring system. The two phenyl rings are inclined at 52.68 (7)°. The S atom has a distorted tetra-hedral configuration. In the crystal, weak C-H⋯O inter-actions link the mol-ecules, forming a helical chain along the b-axis direction.

Crystal structure of 4-amino-benzoic acid-4-methyl-pyridine (1/1).

In the title 1:1 adduct, C6H7N·C7H7NO2, the carb-oxy-lic acid group is twisted at an angle of 4.32 (18)° with respect to the attached benzene ring. In the crystal, the carb-oxy-lic acid group is linked to the pyridine ring by an O-H⋯N hydrogen bond, forming a dimer. The dimers are linked by N-H⋯O hydrogen bonds, generating (010) sheets.

Crystal structure of (2-bromo-methyl-1-phenyl-sulfonyl-1H-indol-3-yl)(phen-yl)methanone.

In the title compound, C22H16BrNO3S, the phenyl rings make dihedral angles of 84.81 (16) and 61.67 (17)° with the indole ring system (r.m.s. deviation = 0.012 Å), while the phenyl rings are inclined to one another by 69.5 (2)°. The mol-ecular structure is stabilized by weak intra-molecular C-H⋯O hydrogen bonds. The sulfonyl S atom has a distorted tetra-hedral configuration. In the crystal, there are no significant inter-molecular inter-actions present.

Crystal structure of 4-(di-methyl-amino)-pyridinium 4-amino-benzoate dihydrate.

In the title hydrated mol-ecular salt, C7H11N2 (+)·C7H6NO2 (-)·2H2O, the cation is protonated at the pyridine N atom and the dihedral angle between the benzene ring and the CO2 (-) group in the anion is 8.5 (2)°. In the crystal, the cation forms an N-H⋯O hydrogen bond to the anion and the anion forms two N-H⋯O hydrogen bonds to adjacent water mol-ecules. Both water mol-ecules form two O-H⋯O hydrogen bonds to carboxyl-ate O atoms. In combination, these hydrogen bonds generate a three-dimensional network and two weak C-H⋯π inter-actions are also observed.

Crystal structure of [1-(3-eth-oxy-2-oxido-benzyl-idene-κO (2))-4-phenyl-thio-semicarbazidato-κ(2) N (1),S](tri-phenylphosphane-κP)nickel(II).

In the title complex, [Ni(C16H15N3O2S)(C18H15P)], the Ni(II) atom has a distorted tetra-hedral coordination geometry, comprised of N, S, O and P atoms of the tridentate thiosemicarbazide ligand and the P atom of the triphenylphosphane ligand. The benzene ring makes a dihedral angle of 53.08 (11)° with the phenyl ring of the phenyl-thio-semicarbazide moiety and dihedral angles of 73.69 (11), 20.38 (11) and 71.30 (11)° with the phenyl rings of tri-phenyl-phosphane ligand. A pair of N-H⋯N hydrogen bonds generates an R 2 (2)(8) ring graph-set motif. The eth-oxy group is disordered over two positions, with site occupancies of 0.631 (9) and 0.369 (9). The mol-ecular structure is stabilized by a weak intra-molecular C-H⋯O hydrogen bond. In the crystal, weak N-H⋯N and C-H⋯π inter-actions connect the mol-ecules, forming a three-dimensional network.