Crystal structure of anthracen-9-yl(3,6-dimethoxynaphthalen-2-yl)methanone: Decisive factors for formation of two-fold helical molecular assemblies in three directions affording chiral crystal

The titled compound of 3-(anthracen-9-carbonylated) 2,7-dimethoxynaphthalene, anthracen-9-yl(3,6-dimethoxynaphthalen-2-yl)methanone, affords as chiral crystals belonging to P 2 ₁ 2 ₁ 2 ₁ space group. To investigate the leading factors of chiral supramolecular crystallisation, the crystal structural characteristics of the titled compound were compared with the two homologous 3-aroylated 2,7-dimethoxynaphthalene compounds, 3-benzoylated and 3-(1-naphthoylated) derivatives, giving achiral crystals of P 2 ₁ /c space group, along with their mother skeleton molecule of 2,7-dimethoxynaphthalene, which also gives chiral crystals with P 2 ₁ 2 ₁ 2 ₁ space group. The spatial features of single molecular crystal structure, molecular accumulation fashion, non-covalent bonding interactions, and proximity of molecules in crystal have been measured among four compounds. In the crystalline single molecular structure of the titled 9-anthracenecarbonyl compound, the 2,7-dimethoxynaphthalene ring connects to the ketonic carbonyl moiety with almost perpendicular fashion and anthracene ring connects to the ketonic carbonyl moiety with a nearly coplanar alignment. On the other hand, in the crystalline single molecular structures of the benzoylated and naphthoylated homologues, the ketonic carbonyl groups connect to arene rings with moderate twist angles. In crystal packings of the benzoylated and 1-naphthoylated homologues, the centrosymmetric dimeric aggregations with pairs of complementary non-classical hydrogen bonds are observed. The titled compound is observed to form two-fold helical molecular assemblies with non-classical hydrogen bonds along a -axis. Hirshfeld surface analysis has emphasised that these packing motifs afford different effects to the molecular packing. The titled anthroylated compound has the largest number of molecules in close proximity among three compounds. The crystal structures of the four compounds including non-aroylated 2,7-dimethoxynaphthalene from the viewpoint of formation potential of chiral crystal have been interpreted by the transition of the types and ratio of the effective non-classical hydrogen bonds functioning inter- and intramolecular modes under the prior influence led by ketonic carbonyl group participating interactions.