2-(2,7-Dimeth-oxy-1-naphtho-yl)benzoic acid.

In the title compound, C(20)H(16)O(5), the dihedral angle between the naphthalene ring system and the benzene ring is 67.43 (5)°. The bridging carbonyl C-C(=O)-C plane makes dihedral angles of 82.

(8-Bromo-2-hydroxy-7-methoxy-1-naph-thyl)(4-chlorobenzoyl)methanone.

In the title compound, C(18)H(12)BrClO(3), the naphthalene ring system and the benzene ring make a dihedral angle of 82.18 (9)°. The conformation around the central C=O group is such that the C=O bond vector forms a larger angle to the plane of the naphthalene ring system than to the plane of the benzene ring, viz.

2,7-Dimethoxy--1-(4-nitro-benzo-yl)-naphthalene.

In the title compound, C(19)H(15)NO(5), the dihedral angle between the naphthalene ring system and the benzene ring is 61.97 (5)°. The dihedral between the naphthalene ring system and the bridging carbonyl C-C(=O)-C plane is 54.

Methyl 4-(2,7-dimeth-oxy-1-naphtho-yl)benzoate.

In the title compound, C(21)H(18)O(5), the dihedral angle between the naphthalene ring system and the benzene ring is 86.65 (6)°. The bridging carbonyl C-C(=O)-C plane makes dihedral angles of 83.

Bis(4-bromo-benzo-yl)(2,7-dimethoxy-naphthalene-1,8-di-yl)dimethanone.

In the title compound, C(26)H(18)Br(2)O(4), the two 4-bromo-benzoyl groups at the 1- and 8-positions of the naphthalene ring system are anti to each other. The dihedral angle between the two benzene rings is 50.92 (14)°.

(4-Chlorophenyl)(2-hydroxy-7-methoxynaphthalen-1-yl)methanone.

The title compound, C(18)H(13)ClO(3), has an intra-molecular O-H⋯O=C hydrogen bond between the carbonyl group and the hydr-oxy substituent on the naphthalene ring system. The angle between the C=O bond plane and the naphthalene ring system is relatively small [20.96 (8)°].

1-(4-Chloro-benzo-yl)-2,7-dimethoxy-naphthalene.

In the title compound, C(19)H(15)ClO(3), the dihedral angle between the naphthalene ring system and the benzene ring is 72.06 (7)°. The 4-chloro-phenyl group and the carbonyl group are almost coplanar.

1,8-Dibenzoyl-2,7-dimethoxy-naphthalene.

The mol-ecule of the title compound, C(26)H(20)O(4), is located on a twofold rotation axis. The two benzoyl groups are situated in an anti orientation. The dihedral angle between the mean planes of the phenyl ring and the naphthalene ring system is 80.

2,7-Bis(4-acetyl-phen-oxy)naphthalene.

The title compound, C(26)H(20)O(4), has an asymmetrical conformation at 193 K. The 4-acetyl-phenyl groups are twisted away from the the naphthalene ring system, with one benzene ring turned towards the 1-position of the naphthalene ring and the other benzene ring turned towards the 6-position. The inter-planar angles between the mean planes of the benzene rings and the naphthalene ring system are 68.

2-(4-Chloro-benzo-yl)-3,6-dimethoxy-naphthalene.

In the title compound, C(19)H(15)ClO(3), the inter-planar angle between the naphthalene and benzene ring systems is 62.67 (6)°. The carbonyl group is twisted from both ring planes, with torsion angles of -44.

2,2'-Dimethoxy-biphen-yl.

The mol-ecule of the title compound, C(14)H(14)O(2), lies on a crystallographic twofold axis perpendicular to the central C-C bond; there is one half-mol-ecule in the asymmetric unit. The angle between the least-squares planes of the two aromatic rings is 66.94 (7)°.