CRYSTAL STRUCTURE OF 1,8-BIS(4-FLUOROBENZOYL)NAPHTHALENE-2,7-DIYL DIBENZOATE: ROLE OF (SP2)C–H…F HYDROGEN BONDING AS DISTINCTLY STRONG INTERACTION AMONG NON-CLASSICAL HYDROGEN BONDS CONTRIBUTING STABILITY OF THE CRYSTAL

In crystal of 1,8-bis(4-fluorobenzoyl)naphthalene-2,7-diyl dibenzoate, C 38 H 22 O 6 F 2 , the phenyl rings of benzoyloxy groups and the naphthalene ring demonstrate largely disproportionate interplanar angles [38.97 (7)° and 52.62 (6)°] different from those between 4-fluorobenzoyl group and the naphthalene ring core [71.24 (5)° and 78.85 (6)°].  One of two benzoyloxy group s has three effective intra molecular interactions [(benzoyloxy) C―H ( o -) ···O (benzoyloxy), (naphthalene) C―H (6-) ···O=C (benzoyloxy), and (benzoyloxy) C―H ( o -) ···π (4-fluorobenzoyl) hydrogen bonds] and the other has no intra molecular interactions.  In crystal, the molecules of identical enantiomeric isomer are unidirectionarly arranged along the b axis through (4-fluorobenzoyl)C―H ( m -) ···O=C(4-fluorobenzoyl) hydrogen bonding interactions forming columnar structure.  Moreover, a column is connected with the mirror imaged column composed of the opposite enantiomeric isomers into centrosymmetric dimer aggregates by three types of complementary interactions, i.e. , (benzoyloxy)C―H ( m -) ···F, (4-fluorobenzoyl)C―H ( m -) ···π(4-fluorobenzoyl), and (4-fluorobenzoyl)C―H ( m -) ···π(benzoyloxy) hydrogen bondings.  The tubular structures thus formed are stacked parallel to the ac plane via (benzoyloxy)C―H ( p -) …F, (benzoyloxy)C―H ( m -) …π(benzoyloxy), (naphthalene)C―H (6-) …O=C(4-fluorobenzoyl), and (4-fluorobenzoyl)C―H ( o -) …O=C(benzoyloxy) hydrogen bonds.  In homologous compound, a fluoro group-free derivative for title compound, the enantiomeric isomer and the opposite enantiomeric counterpart isomer are alternately arranged in a head-to-tail fashion through (benzoyl)C–H ( p -) …O=C(benzoyl)hydrogen bonds along b -axis.  The zigzagged columns are aligned along a -axis with inversion center to form a sheet structure.  However, there are no effective non-covalent bonding interactions between the zigzagged columns.  In other words, the molecular packing structure of the homologous compound is governed by solely one strong (benzoyl)C–H ( p -) …O=C(benzoyl) hydrogen bonds, contrary to the organization of supramolecular architecture in title compound ascribed to cooperative unidirectional (4-fluorobenzoyl)C–H ( m -) …O=C(4-fluorobenzoyl) hydrogen bonds and bidirectional (benzoyloxy)C–H ( m -/ p -) …F hydrogen bonds.