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

Genta Takahara,Kazuki Ogata,Rei Sakamoto,Takeshi Yokoyama,Takahiro Mido,Shinji Ohisa,Akiko Okamoto,Noriyuki Yonezawa

doi:10.17628/ecb.2017.6.31-37

Genta Takahara, Kazuki Ogata + Show 6 more

Open Access

https://doi.org/10.17628/ecb.2017.6.31-37

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Abstract

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.

Highlights

Supramolecular architecture[1,2,3] along with supramolecular chemistry[4,5,6,7,8,9] has become of interest in recent years from the viewpoint of green chemistry and novel phase of functional device material development
To grasp nature of weak hydrogen bonds including “non-classical” hydrogen bonds where C–H group acts as hydrogen donor, for example, has scarcely achieved probably because they are often hidden by strong hydrogen bonds
The molecular packing of 1,8-diaroylated 2,7dialkoxynaphthalene compounds are mainly stabilized by weak hydrogen bonds

Summary

Introduction

Supramolecular architecture[1,2,3] along with supramolecular chemistry[4,5,6,7,8,9] has become of interest in recent years from the viewpoint of green chemistry and novel phase of functional device material development. The research primarily relies on knowledge of the characteristics of non-covalent bonding interactions including atomic geometrical and molecular orientation features.[10,11,12,13] Attempts of formation of tough hydrogen bonds involving CONR2 group and OH group, and COOH group and NH2 group were undertaken both experimentally and theoretically.[14,15,16] These have been successfully employed for the preparation of numerous molecular assemblies. The crystal structure is discussed from the standpoint of clarification of the correlation among single molecular structure, non-covalent bonding interactions, and molecular packing structure through comparison with the fluoro group-free homologous compound, 1,8-dibenzoylnaphthalene-2,7-diyl dibenzoate.[24]

Materials and methods

Synthetic procedures

Results and discussion