(2,7-Dimethoxynaphthalen-1-yl)(4-methoxyphenyl)methanone

In the molecule of the title compound, C20H18O4, the dihedral angle between the naphthalene ring system and the benzene ring is 81.74 (5)°. An intermolecular C—H⋯O interaction is formed between an H atom at the 6-position of the naphthalene ring and the O atom of the methoxy group at the 7-position.

In the molecule of the title compound, C 20 H 18 O 4 , the dihedral angle between the naphthalene ring system and the benzene ring is 81.74 (5) . An intermolecular C-HÁ Á ÁO interaction is formed between an H atom at the 6-position of the naphthalene ring and the O atom of the methoxy group at the 7-position.   Table 1 Hydrogen-bond geometry (Å , ).
As a part of our ongoing studies on the molecular structures of these kinds of homologous molecules, the X-ray crystal structure of the title compound, 1-aroylated naphthalene bearing methoxy groups on aroyl group, is discussed in this article.
The molecular structure of the title compound is displayed in Fig. 1. The dihedral angle between the best planes of the phenyl ring and the naphthalene ring is 81.74 (5) °.
The dihedral angle between the naphthalene ring system and the bridging ketonic carbonyl C-C(=O)-C plane is larger than that between the phenyl ring and the bridging carbonyl plane [74.77 (6)° versus. 13.27 (6) °].
In the molecular packing, C-H···O interactions between the aromatic hydrogen atoms at the 6-position of the naphthalene ring and the methoxy oxygen atoms at the 7-position are observed (C5-H5···O3 = 2.51 Å; symmetry code: - x, -y, -z; Fig. 2). Moreover, the naphthalene rings are aligned in parallel to each other along b axis (Fig. 3).

Refinement
All H atoms were found in a difference map and were subsequently refined as riding atoms, with C-H = 0.95 (aromatic) and 0.98 (methyl) Å with U ĩso (H) = 1.2 U eq (C).

Figure 1
Molecular structure with the atom-labeling scheme and displacement ellipsoids drawn at the 50% probability level.    Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.