Crystal structure of 1,2-bis-(4-fluoro-phen-yl)-1-hy-droxy-2,3,8-tri-meth-oxy-acenaphthene: formation of a five-membered intra-molecular O-H⋯O hydrogen-bonded ring.

The structure of the title compound, C27H22F2O4, at 193 K has triclinic (P ) symmetry. The hy-droxy and meth-oxy groups at the 1,2-positions of the acenaphthene core display a cis configuration. Both substituents are involved in the formation of a five-membered intra-molecular O-H⋯O hydrogen-bonded ring. The 4-fluoro-phenyl rings make dihedral angles of 87.02 (7) and 51.86 (8)° with the naphthalene ring system. In the crystal, a pair of non-classical C-H⋯O hydrogen bonds forms centrosymmetric dimeric structures. The dimeric aggregates are linked in the ac plane through non-classical C-H⋯F hydrogen bonds and C-H⋯π interactions.

Crystal structure and Hirshfeld surface analysis of 2-hy-droxy-7-meth-oxy-1,8-bis-(2,4,6-tri-chloro-benzo-yl)naphthalene.

In the title compound, C25H12Cl6O4, the two carbonyl groups are oriented in a same direction with respect to the naphthalene ring system and are situated roughly parallel to each other, while the two 2,4,6-tri-chloro-benzene rings are orientated in opposite directions with respect to the naphthalene ring system: the carbonyl C-(C=O)-C planes subtend dihedral angles of 45.54 (15) and 30.02 (15)° to the naphthalene ring system are. The dihedral angles formed by the carbonyl groups and the benzene rings show larger differences, the C=O vectors being inclined to the benzene rings by 46.39 (16) and 79.78 (16)°. An intra-molecular O-H⋯O=C hydrogen bond forms an S(6) ring motif. In the crystal, no effective inter-molecular hydrogen bonds are found; instead, O⋯Cl and C⋯Cl close contacts are observed along the 21 helical-axis direction. The Hirshfeld surface analysis reveals several weak interactions, the major contributor being Cl⋯H/H⋯Cl contacts.

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.

Hydrogen bonding between aromatic H and F groups leading to a stripe structure with R- and S-columns: the crystal structure of (2,7-dimethoxynaphthalen-1-yl)(3-fluorophenyl)methanone and comparison with its 1-aroylnaphthalene analogues.

In the molecule of (2,7-dimethoxynaphthalen-1-yl)(3-fluorophenyl)methanone, C19H15FO3, (I), the dihedral angle between the plane of the naphthalene ring system and that of the benzene ring is 85.90 (5)°. The molecules exhibit axial chirality, with either an R- or an S-stereogenic axis. In the crystal structure, each enantiomer is stacked into a columnar structure and the columns are arranged alternately to form a stripe structure. A pair of (methoxy)C-H...F hydrogen bonds and π-π interactions between the benzene rings of the aroyl groups link an R- and an S-isomer to form a dimeric pair. These dimeric pairs are piled up in a columnar fashion through (benzene)C-H...O=C and (benzene)C-H...OCH3 hydrogen bonds. The analogous 1-benzoylated compound, namely (2,7-dimethoxynaphthalen-1-yl)(phenyl)methanone [Kato et al. (2010). Acta Cryst. E66, o2659], (II), affords three independent molecules having slightly different dihedral angles between the benzene and naphthalene rings. The three independent molecules form separate columns and the three types of column are connected to each other via two C-H...OCH3 hydrogen bonds and one C-H...O=C hydrogen bond. Two of the three columns are formed by the same enantiomeric isomer, whereas the remaining column consists of the counterpart isomer. In the case of the fluorinated 1-benzoylated naphthalene analogue, namely (2,7-dimethoxynaphthalen-1-yl)(4-fluorophenyl)methanone [Watanabe et al. (2011). Acta Cryst. E67, o1466], (III), the molecular packing is similar to that of (I), i.e. it consists of stripes of R- and S-enantiomeric columns. A pair of C-H...F hydrogen bonds between R- and S-isomers, and C-H...O=C hydrogen bonds between R(or S)-isomers, are also observed. Consequently, the stripe structure is apparently induced by the formation of R...S dimeric pairs stacked in a columnar fashion. The pair of C-H...F hydrogen bonds effectively stabilizes the dimeric pair of R- and S-enantiomers. In addition, the co-existence of C-H...F and C-H...O=C hydrogen bonds makes possible the formation of a structure with just one independent molecule.

Comparative structural analysis of 2,7-diethoxy-1,8-bis(4-phenoxybenzoyl)naphthalene and its homologues: orientation of the 4-phenoxybenzoyl groups at the 1- and 8-positions of the naphthalene ring.

The title molecule, C40H32O6, possesses crystallographically imposed twofold symmetry, with the central two C atoms of the naphthalene unit sited on the rotation axis. The two 4-phenoxybenzoyl groups in the molecule are twisted away from the attached naphthalene unit, with a torsion angle of 66.76 (15)° between the naphthalene unit and the carbonyl group (C-C-C=O), and are oriented in mutually opposing directions (anti orientation). There is an apparent difference in the conformations of the 4-phenoxybenzoyl groups at the 1- and 8-positions of the naphthalene ring between the title molecule and its methoxy-bearing homologue [Hijikata et al. (2010). Acta Cryst. E66, o2902-o2903]. Whilst the 4-phenoxybenzoyl groups in 2,7-diisopropoxy-1,8-bis(4-phenoxybenzoyl)naphthalene [Yoshiwaka et al. (2013). Acta Cryst. E69, o242] are situated in the same anti orientation as the title molecule, those of 2,7-dimethoxy-1,8-bis(4-phenoxybenzoyl)naphthalene are oriented in the same direction with respect to the naphthalene ring system, i.e. in a syn orientation.

Crystal structure of 1,8-dibenzoyl-2,7-di-phen-oxy-naphthalene.

In the title compound, C36H24O4, the benzene rings of the benzoyl and phen-oxy groups make dihedral angles of 75.01 (4), 75.78 (4), 83.17 (5) and 80.84 (5)° with the naphthalene ring system. In the crystal, two types of C-H⋯π inter-actions between the benzene rings of the benzoyl groups and the naphthalene unit, and two kinds of π-π inter-actions between the benzene rings, with centroid-centroid distances of 3.879 (1) and 3.696 (1) Å, are observed.

Crystal structure of 1-(2-fluoro-benzo-yl)-2,7-di-meth-oxy-naphthalene.

The asymmetric unit of the compound, C19H15FO3, contains two independent molecules. Each molecule has essentially the same feature of non-coplanarly accumulated aromatic rings whereby the aroyl group at the 1-position of the naphthalene ring system is twisted almost perpendicularly to the ring system [dihedral angles of 86.52 (8) and 89.66 (8)°]. In the crystal structure, mol-ecules of the same conformer are stacked into columns parallel to the a axis by van der Waals inter-actions only.

Crystal structure of 2,7-dieth-oxy-1,8-bis-(4-nitro-benzo-yl)naphthalene.

The title compound, C28H22N2O8, possesses crystallographically imposed twofold symmetry, with the two central carbon atoms of the naphthalene unit lying on the rotation axis. The two benzoyl groups in the mol-ecule are twisted away from the attached naphthalene unit with a C-C-C=O torsion angle of 49.05 (15)° between the naphthalene unit and the carbonyl group. The dihedral angle between the naphthalene ring system and the benzene ring is 77.17 (5)°. In the crystal, pairs of C-H⋯O=C hydrogen bonds link the mol-ecules into a double-column structure along the c axis. The mol-ecules are further linked by C-H⋯O=N hydrogen bonds, forming a three-dimensional network. C-H⋯π inter-actions between the methyl-ene group and the naphthalene unit and π-π inter-actions between the naphthalene ring systems [centroid-centroid distances of 3.7858 (7)-3.7860 (7) Å] are also observed.

Head-to-tail square-shaped cyclic hydrogen bonds leading to dimeric aggregates: 1,8-dibenzoyl-2,7-dihydroxynaphthalene and a comparison with its analogous benzoylnaphthalene.

The title compound, C24H16O4, crystallized with two independent molecules in the asymmetric unit. Both carbonyl groups in these molecules form intramolecular O-H...O=C hydrogen bonds with neighbouring hydroxy groups, affording six-membered cyclic structures. In the crystal, dimeric aggregates arise from two intermolecular O-H···O=C hydrogen bonds between both independent molecules, forming head-to-tail square-shaped cyclic ···O···H···O···H··· hydrogen bonds. These dimeric aggregates are connected into layers in the bc plane by intermolecular (naphthalene)C-H...O=C interactions. On the other hand, the analogous compound bearing methoxy groups at the 2- and 7-positions of the naphthalene ring, namely 1,8-dibenzoyl-2,7-dimethoxynaphthalene [Nakaema et al. (2008). Acta Cryst. E64, o807], forms a three-dimensional molecular network via C-H···O=C and π-π interactions between the benzoyl groups. These results show that the intramolecular O-HvO=C hydrogen bonds in the title compound control the orientations of the benzoyl groups and thus promote the formation of the cyclic intermolecular O-H···O=C interactions involving the same donor and acceptor groups in pairs of molecules.

[2,7-Dieth-oxy-8-(4-fluoro-benzo-yl)naphthalen-1-yl](4-fluoro-phen-yl)methanone.

In the mol-ecule of the title compound, C28H22F2O4, the benzoyl groups are aligned almost anti-parallel and the fluorobenzene rings form a dihedral angle of 14.12 (7)°. The dihedral angles between the 2,7-dieth-oxy-naphthalene ring system and the benzene rings are 70.00 (4) and 67.28 (4)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯F hydrogen bonds, forming layers parallel to the ab plane. The layers are further connected by π-π inter-actions [centroid-centroid distances of 3.6115 (10) Å] into a three-dimensional structure.

(4-Eth-oxy-benzo-yl)[8-(4-eth-oxy-benzo-yl)-2,7-di-meth-oxy-naphthalen-1-yl]methanone.

The title mol-ecule, C30H28O6, possesses crystallographically imposed twofold symmetry, with two central C atoms in the naphthalene unit lying on the rotation axis along [001]. The 4-eth-oxy-benzoyl groups at the peri positions of the naphthalene ring system are disordered over two sets of sites with occupancies of 0.769 (4) and 0.231 (4). They are directed in opposite directions from the naphthalene plane (anti orientation). For the major component, the dihedral angle between the aroyl benzene ring and the naphthalene ring system is 75.62 (13)° [minor component 75.5 (4)°], and that between the aroyl benzene rings is 32.58 (15)°. In the crystal, mol-ecules are linked via C-H⋯O and C-H⋯π inter-actions, forming a three-dimensional network.

(2,7-Di-meth-oxy-naphthalen-1-yl)(naph-thalen-1-yl)methanone.

The asymmetric unit of the title compound, C23H18O3, contains two independent mol-ecules (A and B). Each mol-ecule has essentially the same conformation (r.m.s. deviation of fitted mol-ecules = 0.173 Å) with the aromatic rings twisted in a near perpendicular manner. The dihedral angles between the two naphthalene ring systems are 79.07 (4) and 88.19 (4)° in the two independent mol-ecules. In the crystal, the A mol-ecules are connected by C-H⋯O inter-actions, forming chains along the b-axis direction. Further C-H⋯O inter-actions between the H atoms of the meth-oxy group and the O atoms of the carbonyl units link the A and B mol-ecules, forming a three-dimensional network.

{2,7-Dieth-oxy-8-[(naphthalen-1-yl)carbon-yl]naph-thalen-1-yl}(naphthalen-1-yl)methanone.

In the title compound, C36H28O4, the 1-naphthoyl groups at the 1- and 8-positions of the central 2,7-dieth-oxy-naphthalene ring system are aligned almost anti-parallel and make a dihedral angle of 76.59 (4)°. The dihedral angles between the central 2,7-dieth-oxy-naphthalene ring system and the terminal naphthalene ring systems are 86.48 (4) and 83.97 (4)°. In the crystal, C-H⋯π inter-actions between the central naphthalene ring systems and the naphthoyl groups are observed along the a axis, with the mol-ecules forming a columnar structure. The columns are linked into chains parallel to the b axis by C-H⋯O inter-actions.

1,8-Bis(4-fluoro-benzo-yl)naphthalen-2,7-diyl dimethane-sulfonate.

The mol-ecule of the title compound, C26H18F2O8S2, lies across a crystallographic twofold rotation axis. The benzene rings of the 4-fluorobenzoyl groups make dihedral angles of 78.93 (12)° with the naphthalene ring system. An intra-molecular C-H⋯π inter-action occurs. In the crystal, a number of C-H⋯O inter-actions link the mol-ecules, forming a three-dimensional structure.

Bis(1-benzoyl-7-meth-oxy-naphthalen-2-yl) terephthalate.

The title molecule, C44H30O8, lies about a crystallographic inversion centre located at the centre of the central benzene ring. The benzene rings in the benzoyl and the terephthalate units make dihedral angles of 67.05 (7)° and 57.57 (7)°, respectively, with the naphthalene ring system. There is an intra-molecular C-H⋯O inter-action between the ketonic carbonyl O atom and an H atom on the naphthalene ring system. In the crystal, C-H⋯O inter-action of the benzene ring in the benzoyl group and weak C=O⋯π inter-action [O⋯centroid = 3.375 (2) Å] of the naphthalene ring with the O atom in the ketonic carbonyl group are observed. These inter-actions form layers parallel to the bc plane.

[2,7-Dimeth-oxy-8-(4-meth-oxy-benzo-yl)naphthalen-1-yl](4-meth-oxy-phen-yl)methanone chloro-form monosolvate.

In the title compound, C28H24O6·CHCl3, the two 4-meth-oxy-benzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost anti-parallel, the benzene rings making a dihedral angle of 25.76 (7)°. The naphthalene ring system makes dihedral angles of 72.51 (7) and 73.33 (7)° with the benzene rings. In the crystal, the naphthalene mol-ecules are linked by C-H⋯O inter-actions, forming a helical chain along the b-axis direction. A C-H⋯Cl inter-action is also observed between the aroylated naphthalene and chloro-form mol-ecules. The chloro-form mol-ecule is disordered over two positions with site occupancies of 0.478 (5) and 0.522 (5).

(8-Benzoyl-2,7-dieth-oxy-naphthalen-1-yl)(phen-yl)methanone.

In the title compound, C28H24O4, the benzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost anti-parallel, and the benzene rings make a dihedral angle of 20.03 (7)°. The dihedral angles between the benzene rings and the naphthalene ring system are 68.42 (5) and 71.69 (5)°. In the crystal, adjacent mol-ecules are linked via C-H⋯O hydrogen bonds, forming chains propagating along [100].

(2,7-Dimeth-oxy-naphthalen-1-yl)(4-meth-oxy-phen-yl)methanone.

In the mol-ecule of the title compound, C20H18O4, the dihedral angle between the naphthalene ring system and the benzene ring is 81.74 (5)°. An inter-molecular C-H⋯O inter-action is formed between an H atom at the 6-position of the naphthalene ring and the O atom of the meth-oxy group at the 7-position.

{2,7-Dieth-oxy-8-[(naphthalen-2-yl)carbon-yl]naphthalen-1-yl}(naphthalen-2-yl)methanone.

In the title compound, C36H28O4, the two 2-naphthoyl groups at the 1- and 8-positions of the central 2,7-dieth-oxy-naphthalene ring system are aligned almost anti-parallel and make a dihedral angle of 48.35 (5)°. The dihedral angles between the central 2,7-dieth-oxy-naphthalene ring system and the terminal naphthalene ring systems are 77.64 (4) and 73.73 (4)°. In the crystal, mol-ecules are linked into chains along the a-axis direction by dual C-H⋯O inter-actions between naphthoyl groups.

(8-Benzoyl-2,7-dimeth-oxy-naphthalen-1-yl)(4-phen-oxy-phen-yl)methanone.

In the mol-ecule of the title compound, C32H24O5, the benzoyl group and the 4-phenoxy substituted benzoyl group at the 1- and 8-positions of the naphthalene ring system are aligned almost anti-parallel. The two benzene rings make a dihedral angle of 21.18 (10)°, and are inclined to the naphthalene ring system by 86.53 (9) and 82.95 (8)°, respectively. In the crystal, C-H⋯O inter-actions are observed involving aromatic and meth-oxy H atoms with ketonic carbonyl O atoms, as well as C-H⋯π inter-actions between aromatic H atoms and the π-systems of naphthalene and benzene rings. These interactions form a three-dimensional architecture and afford a waved alignment of the naphthalene ring systems along the c axis.