Anthracene Ring System Research Articles

2-(10-Bromoanthracen-9-yl)-N-phenylaniline

In the title compound, C26H18BrN, the central benzene ring makes dihedral angles with its adjacent anthracene ring system and pendant benzene ring of 87.49 (13) and 62.01 (17)°, respectively. The N—H moiety is sterically blocked from forming a hydrogen bond, but weak C—H...π interactions occur in the extended structure.

10-Bromo-N,N-di-phenyl-anthracen-9-amine.

In the title compound, C26H18BrN, the dihedral angles between the anthracene ring system and the phenyl rings are 89.51 (14) and 74.03 (15)°. In the extended structure, a weak C-H⋯Br inter-action occurs, which generates [100] chains, but no significant π-π or C-H⋯π inter-actions are observed.

Crystal structure and Hirshfeld surface analysis of 4-{[(anthracen-9-yl)meth-yl]amino}-benzoic acid.

In the mol-ecule of the title anthracene derivative, C22H17NO2, the benzene ring is inclined to the mean plane of the anthracene ring system (r.m.s. deviation = 0.024 Å) by 75.21 (9)°. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming classical carb-oxy-lic acid inversion dimers with an R 2 2(8) ring motif. The dimers are linked by C-H⋯π inter-actions, forming a supra-molecular framework.

Gephyyamycin and cysrabelomycin, two new angucyclinone derivatives from the Streptomyces sp. HN-A124

Gephyyamycin (1) owned the rare 3,12a-epoxybenz[a]anthracene ring system, and cysrabelomycin (2) possessed an acetylated cysteine group, two new angucyclinone derivatives were isolated from the rice solid fermentation of the marine-derived Streptomyces sp. HN-A124, an actinobacterium isolated from the marine sediments collected from Hainan Province, China. Their structures were elucidated on the basis of MS, NMR spectroscopic, X-ray diffration data analyses and quantum chemical calculations of the electronic circular dichroism (ECD) spectra. Compound 2 appeared to show moderate cytotoxicity against human prostate cancer PC3 and human ovarian carcinoma A2780 cell lines with IC50 values of 19.39 and 10.23 μM, respectively; on the other hand, compound 2 also exhibited moderate antibacterial activities against Staphylococcus aureus and Candida albicans with an MIC value of 20.0 and 20 μM, respectively.

Crystal structure and optical properties of fused-ring chalcone (E)-3-(anthracen-9-yl)-1-(4-nitro-phen-yl)prop-2-en-1-one.

The title compound, C23H15NO3, adopts an s-cis conformation with respect to the ethyl-ene C=C and carbonyl C=O double bonds in the enone unit. The mol-ecule is significantly twisted with a dihedral angle of 48.63 (14)° between the anthracene ring system and the benzene ring. In the crystal, mol-ecules are linked into inversion dimers with an R 2 2(10) graph-set motif via pairs of C-H⋯O hydrogen bonds. The inter-molecular inter-actions were analysed and qu-anti-fied by Hirshfeld surface analysis. The mol-ecular structure was optimized and a small HOMO-LUMO energy gap of 2.55 eV was obtained using the DFT method at the B3LYP/6-311 G++(d,p) level of theory. This value is in close agreement with the experimental value of 2.52 eV obtained from the UV-vis analysis. The crystal used was a two-component merohedral twin with a refined ratio of 0.1996 (16):0.8004 (16).

Crystal structures, DFT studies and UV-visible absorption spectra of two anthracenyl chalcone derivatives.

The crystal structures of (E)-1-(anthracen-9-yl)-3-(3H-indol-2-yl)prop-2-en-1-one, C25H17NO, and (E)-1-(anthracen-9-yl)-3-[4-(di-methyl-amino)-naphthalen-1-yl]prop-2-en-1-one, C29H23NO, are reported. In each case the anthracene ring system and pendant ring system are almost perpendicular to each other [dihedral angles = 75.57 (7)° and 70.26 (10)°, respectively]. In the extended structures, weak N-H⋯O, C-H⋯O and C-H⋯π inter-actions influence the centrosymmetric crystal packing. Density functional theory calculations were carried out using a 6-311 G++(d,p) basis set and the calculated structures are in good agreement with the crystal structures. The compounds were also characterized by UV-Vis absorption spectroscopy and the smallest (HOMO-LUMO) energy gaps of 2.89 and 2.54 eV indicate the enhanced non-linear responses (inter-molecular charge transfers) of these systems.

Kiamycins B and C, unusual bridged angucyclinones from a marine sediment-derived Streptomyces sp.

Kiamycins B (1) and C (2), two unusual angucyclinones bearing a novel 6,12-epoxybenz[a]anthracene ring system, were isolated from the cultures of a marine sediment-derived Streptomyces sp. along with one structurally related derivative 3. Their structures and stereochemistries were determined by spectroscopic analyses, single-crystal X-ray diffraction and electronic circular dichroism (ECD) calculations.

Synthesis and evaluation of pyridinium-hydrazone derivatives as potential antitumoral agents.

The hydrazones of 4-hydrazinylpyridinium bearing alkylphenyl groups on pyridinium nitrogen were synthesized and evaluated for their cytotoxic activity against MCF-7, PC3, U2OS, and HEK293 cell lines by Wst1 cell proliferation assay. Cytotoxic activity results indicated that d derivatives having butylene chain; 4 and 5 series having naphthalene and anthracene ring systems showed high cytotoxic activity (IC50 =3.27-8.54μm) on cancer cells. 3d (4-(2-(4-hydroxybenzylidene)hydrazinyl)-1-(4-phenylbutyl)pyridinium bromide) was the most cytotoxic compound with IC50 value of 3.27μm against MCF-7. The most active derivatives (1d, 2d, 3d, 4, and 5 series) were selected to investigate for the effects on autophagy by analyzing the expression of autophagy marker proteins. The conversion of LC3-I to its lipidated form LC3-II is essential for autophagy and related to autophagosomes. According to our results, all tested compounds except for 3d induced lipidated form LC3-II accumulation. Then, the effects of the compounds on p62 protein level were also analyzed by the immunoblotting as the autophagy inhibition results in accumulation of p62. Further molecular mechanistic studies including morphological analysis and live-death assays indicated that all tested compounds (1d, 2d, 3d, 4, and 5 series) are potent antitumoral molecules and all except for 3d have potential to inhibit autophagic flux.

(E)-1,3-Bis(anthracen-9-yl)prop-2-en-1-one: crystal structure and DFT study.

The title compound, C31H20O, was synthesized using a Claisen-Schmidt condensation. The enone group adopts an s-trans conformation and the anthracene ring systems are twisted at angles of 85.21 (19) and 83.98 (19)° from the enone plane. In the crystal, mol-ecules are connected into chains along [100] via weak C-H⋯π inter-actions. The observed band gap of 3.03 eV is in excellent agreement with that (3.07 eV) calculated using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. The Hirshfeld surface analysis indicates a high percentage of C⋯H/H⋯C (41.2%) contacts in the crystal.

Systematic investigation of the excited-state properties of anthracene-dicarboxylic acids

Abstract We report the photophysical properties of three anthracene-dicarboxylic acids – 1,4-anthracene dicarboxylic acid (1,4-ADCA), 2,6-anthracene dicarboxylic acid (2,6-ADCA) and 9,10-anthracene dicarboxylic acid (9,10-ADCA) – in a series of polar aprotic solvents using steady-state absorption spectroscopy, steady-state emission spectroscopy and time-correlated single photon counting emission lifetime spectroscopy. The addition of carboxylic acid functional groups on the anthracene ring perturbs the electronic transitions oriented along the longitudinal and transverse axes to varying degrees, resulting in differences in the photophysical properties. The three anthracene derivatives exhibit very different excited-state properties in basic solution compared to acidic and neutral solutions. Density functional theory (DFT) calculations reveal that the lowest-energy ground-state structures of both 2,6-ADCA and 1,4-ADCA have dihedral angles between the carboxylic acids and aromatic planes of θ = 0°. For 9,10-ADCA, the same dihedral angle increases to θ = 56.6°. Time-dependent DFT calculations suggest that the carboxyl groups of 1,4-ADCA and 2,6-ADCA remain coplanar with the anthracene ring system in the excited state. In contrast, the calculations reveal significant changes between the ground and excited geometries for 9,10-ADCA as the dihedrals decrease from 56.6° to 27.7° in the first excited state, and puckering of the anthracene moiety of 9,10-ADCA is observed.

1-[(Anthracen-9-yl)carbon-yl]-2,7-di-meth-oxy-naphthalene: a chain-like structure composed of face-to-face type dimeric mol-ecular aggregates.

The asymmetric unit of the title compound, C27H20O3, contains two independent mol-ecules (A and B). The anthracene ring system is connected to the 2,7-di-meth-oxy-naphthalene core in a twisted manner, with dihedral angles of 86.38 (5) and 79.36 (8)°, respectively, for conformers A and B. In the crystal, face-to-face type dimeric mol-ecular aggregates of each conformer are observed. The dimer of conformer A is formed by two pairs of C-H⋯π inter-actions, and that of conformer B by a pair of (sp2)C-H⋯O hydrogen bonds. The dimers of conformer A are linked to each other via a π-π stacking inter-action between the anthracene rings to form a chain along the b axis and the chains are aligned along the c axis, forming a sheet structure. The dimers of conformer B are connected to each other via a couple of C-H⋯π inter-actions to form a chain along the b axis. The chains are aligned along the c axis through (sp2)C-H⋯O=C hydrogen bonds, forming a sheet parallel to the bc plane. The sheets of conformers A and B are alternately stacked along the a axis via two kinds of inter-molecular (sp2)C-H⋯O=C hydrogen bonds.

Crystal structure of 6-(p-tol-yl)benzo[b]naphtho[2,3-d]thio-phene and of an ortho-rhom-bic polymorph of 7-phenyl-anthra[2,3-b]benzo[d]thio-phene.

The title compounds, C23H16S, (I), and C26H16S, (II), are benzo-thio-phene derivatives in which the benzo-thio-phene moiety is fused with a naphthalene ring system in (I), and with an anthracene ring system in (II). In (I), the mean plane of the benzo-thio-phene ring system makes a dihedral angle of 2.28 (6)° with the naphthalene ring system, and a dihedral angle of 1.28 (6)° with the anthracene ring system in (II), showing that the fused units are essentially planar. In (I), the 4-methyl-benzene ring substituent makes a dihedral angle of 71.40 (9)° with the naphthalene ring system, while the phenyl ring substituent in (II) makes a dihedral angle of 67.08 (12)° with the anthracene ring system. In the crystals of both compounds, mol-ecules are linked by C-H⋯π inter-actions, leading to the formation of slabs parallel to (001) in (I) and to zigzag chains along [001] in (II). There are also offset π-π inter-actions present within the slabs in (I). In the crystal of (II), they link the chains, forming sheets parallel to (010). The triclinic polymorph of compound (II) has been reported [Sivasakthikumaran et al., (2012 ▸). J. Org. Chem.77, 9053-9071].

Crystal structure of (E)-1(anthracen-9-ylmethylidene)[2-(morpholin-4-yl)eth-yl]amine.

The title compound, C21H22N2O, crystallizes with two independent mol­ecules in the asymmetric unit. In both mol­ecules, the anthracene ring systems are almost planar, with maximum deviations of 0.071 (8) and 0.028 (7) Å, and make dihedral angles of 73.4 (2) and 73.3 (2)° with the least-squares planes formed by the four C atoms of the morpholine rings, which adopt a chair conformation. An intra­molecular C—H⋯π inter­action occurs. In the crystal, the packing is stabilized by weak C—H⋯O hydrogen bonds, which connect pairs of molecules into parallel to the c axis, and C—H⋯π inter­actions.

1-[(E)-Anthracen-9-ylmethylidene]-2-(2,4-dinitrophenyl)hydrazine

In the title Schiff base, C21H14N4O4, the dihedral angle between the two nitro groups and the central benzene ring are 83.6 (5) and 2.6 (6)°. The anthracene ring system and the benzene ring make a dihedral angle of 0.7 (2)°. Intra­molecular N—H⋯O and C—H⋯N hydrogen bonds occur. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules, forming chains along the b-axis direction.

1-(10-Bromoanthracen-9-yl)-1H-imidazole

In the title mol­ecule, C17H11BrN2, the planes of the anthracene ring system [maximum deviation from the mean plane = 0.036 (3) Å] and the imidazole ring form a dihedral angle of 85.14 (14)°. In the crystal, weak C—H⋯N and C—H⋯Br hydrogen bonds link the mol­ecules into double chains propagating along [01-1]. In addition, π–π stacking inter­actions between pairs of benzene rings are observed, with centroid–centroid distances of 3.7968 (17) and 3.8496 (16) Å.

1,5-Bis(piperidin-1-yl)-9,10-anthraquinone

In the centrosymmetric title compound, C24H26N2O2, the piperidine ring adopts a chair conformation and is inclined at a dihedral angle of 37.5 (1)°to the anthracene ring system. In the crystal, adjacent mol­ecules are linked through C—H⋯π and π–π [centroid–centroid distances = 3.806 (1) Å] inter­actions, forming a layer parallel to the bc plane.

9-(4-Methoxyphenyl)anthracene

In the title compound, C21H16O, the dihedral angle between the anthracene ring system and the benzene ring is 74.3 (5)°. The anthracene ring system is essentially planar (r.m.s. deviation = 0.0257 Å) and the meth­oxy group lies in the plane of the benzene ring [C1—O1—C2—C7 torsion angle = 0.5 (2)°]. The crystal structure features π–π [centroid–centroid distance = 3.9487 (12) Å] and C–H⋯π inter­actions, forming a sheet running along the a-axis direction.

Crystalline inclusion compounds of a new diol host featuring a combination of anthracene and 9-fluorenol units

The diol host compound 2 has been synthesised and its behaviour to form crystalline inclusion compounds is discussed in comparison with an analogous ethynylene spaced host compound 1. The rotation around the fluorenol–anthracene bonds in 2 is highly restricted as indicated by solution NMR spectroscopy, molecular mechanics and semi-empirical calculations. Single-crystal X-ray structures of the inclusion complexes of 2 with 1-BuOH (2a), morpholine/H2O (2b) and DMSO (2c) are in agreement with the bent geometry of the anthracene ring system suggested by the calculations. The structures exhibit specific modes of hydrogen bond interactions.

1-(Piperidin-1-yl)-9,10-anthraquinone

In the title compound, C19H17NO2, the piperidine ring adopts a chair conformation. The mean planes of the piperidine ring and the anthracene ring system are inclined at a dihedral angle of 38.7 (1)°. In the crystal, adjacent mol­ecules are linked through C—H⋯π and π–π [centroid–centroid distance = 3.782 (1) Å] inter­actions, forming a layer parallel to the bc plane.

2-(Anthracen-9-yl)-10-meth-oxy-benzo[h]quinoline acetone hemisolvate.

The asymmetric unit of the title structure, C28H19NO·0.5C3H6O, comprises one 2-(anthracen-9-yl)-10-meth­oxy­benzo[h]­quinoline mol­ecule and an acteone mol­ecule with an occupany of 0.5. The solvent mol­ecule is disordered around a centre of symmetry. Its occupancy was determined from NMR data and kept fixed during the refinement. The two conjugated ring systems of the mol­ecule are almost perpendicular to each other; the inter­planar angle between the anthracene and quinoline ring systems is 84.9 (2)°.