Crystal structures and Hirshfeld surface analyses of 4,4′-{[1,3-phenylenebis(methylene)]bis(oxy)}bis(3-methoxybenzaldehyde) and 4,4′-{[(1,4-phenylenebis(methylene)]bis(oxy)}bis(3-methoxybenzaldehyde)

Abstract

The title compounds, C24H22O6 (I) and C24H22O6 (II), each crystallize with half a molecule in the asymmetric unit. The whole molecule of compound (I) is generated by twofold rotation symmetry, the twofold axis bisecting the central benzene ring. The whole molecule of compound (II) is generated by inversion symmetry, the central benzene ring being located on an inversion center. In (I), the outer benzene rings are inclined to each other by 59.96 (10)° and by 36.74 (9)° to the central benzene ring. The corresponding dihedral angles in (II) are 0.0 and 89.87 (12)°. In the crystal of (I), molecules are linked by C—H...O hydrogen bonds and C—H...π interactions, forming ribbons propagating along the [10\overline{1}] direction. In the crystal of (II), molecules are linked by C—H...O hydrogen bonds, forming a supramolecular framework. The Hirshfeld surface analyses indicate that for both compounds the H...H contacts are the most significant, followed by O...H/H...O and C...H/H...C contacts.

Keywords

• crystal structure
• vanillin
• 4-hydroxy-3-methoxybenzaldehyde
• hydrogen bonding
• C—H...O hydrogen bonds
• C—H...π interactions
• supramolecular framework
• Hirshfeld surface analysis
• fingerprint plots