(3,6-Dimethoxy-2-naphthyl)(4-fluorobenzoyl)methanone

In the title compound, C19H15FO3, the dihedral angle between the naphthalene ring system and the benzene ring is 62.93 (5)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 45.55 (6) and 28.62 (7)°, respectively, with the naphthalene ring system and the benzene ring. Weak intermolecular C—H⋯O hydrogen bonds and C—H⋯π interactions stabilize the crystal packing.


Comment
In the course of our study on electrophilic aromatic aroylation of 2,7-dimethoxynaphthalene, peri-aroylnaphthalene compounds have proven to be formed regioselectively with the aid of suitable acidic mediators (Okamoto & Yonezawa, 2009).
The aroyl groups at the 1,8-positions of the naphthalene rings in these compounds are twisted almost perpendicularly but the benzene ring moieties of the aroyl groups tilt slightly toward the exo sides of the naphthalene rings.
The crystal packing is additionally stabilized by two types of intermolecular weak C-H···O hydrogen bondings: One is between the aromatic hydrogen (H17) at meta position to the F group, and the carbonyl oxygen (O1) (Fig.3, Table 1). The other is between an hydrogen (H18A) of the 2-methoxy group which is situated adjacent to the fluorophenyl group, and the ethereal oxygen (O3) of the 7-methoxy group in a neighboring molecule .

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 Rfactors(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.