Bis(1-benzoyl-7-methoxynaphthalen-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 intramolecular C—H⋯O interaction between the ketonic carbonyl O atom and an H atom on the naphthalene ring system. In the crystal, C—H⋯O interaction of the benzene ring in the benzoyl group and weak C=O⋯π interaction [O⋯centroid = 3.375 (2) Å] of the naphthalene ring with the O atom in the ketonic carbonyl group are observed. These interactions form layers parallel to the bc plane.

The title molecule, C 44 H 30 O 8 , 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 intramolecular C-HÁ Á ÁO interaction between the ketonic carbonyl O atom and an H atom on the naphthalene ring system. In the crystal, C-HÁ Á ÁO interaction of the benzene ring in the benzoyl group and weak C=OÁ Á Á interaction [OÁ Á Ácentroid = 3.375 (2) Å ] of the naphthalene ring with the O atom in the ketonic carbonyl group are observed. These interactions form layers parallel to the bc plane.   Table 1 Hydrogen-bond geometry (Å , ). In the course of our study on electrophilic aromatic aroylation of the naphthalene core, 1,8-diaroylnaphthalene compounds have proved to be formed regioselectively by the aid of a suitable acidic mediator (Okamoto & Yonezawa, 2009, Okamoto et al., 2011.
These compounds have non-coplanar structures where the aroyl groups are perpendicularly orientated relative to the naphthalene ring. Crystal structures of the aroylnaphthalene analogues bearing oxybenzoyl groups at the 2,7-positions of the naphthalene ring core namely 1,8-dibenzoylnaphthalene-2,7-diyl dibenzoate (Sakamoto et al., 2012) and 1-benzoylnaphthalene-2,7-diyl dibenzoate (Sakamoto et al., 2013), have been previously determined which show the molecules form the tubular arrangements when the benzene ring of the benzoyl group effectively interacts with the carbonyl moiety of the benzoyloxy group and the naphthalene ring through intermolecular C-H···O and C-H···π interactions.
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 composed of two 1-benzoylnaphthalene units and a terephthalate moiety is reported on herein.
The molecular structure of the title compound is displayed in Fig. 1. The molecule lies on a centre of inversion so that the asymmetric unit contains one-half of the molecules. The benzene rings in the benzoyl group and the terephthalate moiety are twisted away from the naphthalene ring. Two kinds of intramolecular C-H···O interactions, one intramolecular C-H···O interaction between the naphthalene ring and the benzoyl group (C8-H8···O1 = 2.41 Å) and another one between the benzene ring and the ethereal oxygen of the terephthalate moiety (C22-H22···O3 = 2.39 Å), contribute to stabilization of the twisted orientation of each benzene ring against the naphthalene ring ( Fig. 1).

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 iso (H) = 1.2U eq (C).    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.