The crystal structure of the triclinic polymorph of 1,4-bis([2,2′:6′,2′′-terpyridin]-4′-yl)benzene

Abstract

The title triclinic polymorph (Form I) of 1,4-bis([2,2′:6′,2′′-terpyridin]-4′-yl)benzene, C36H24N6, was formed in the presence of the Lewis acid yttrium trichloride in an attempt to obtain a coordination compound. The crystal structure of the orthorhombic polymorph (Form II), has been described previously [Fernandes et al. (2010). Acta Cryst. E66, o3241–o3242]. The asymmetric unit of Form I consists of half a molecule, the whole molecule being generated by inversion symmetry with the central benzene ring being located about a crystallographic centre of symmetry. The side pyridine rings of the 2,2′:6′,2′′-terpyridine (terpy) unit are rotated slightly with respect to the central pyridine ring, with dihedral angles of 8.91 (8) and 10.41 (8)°. Opposite central pyridine rings are coplanar by symmetry, and the angle between them and the central benzene ring is 49.98 (8)°. The N atoms of the pyridine rings inside the terpy entities, N...N...N, lie in trans–trans positions. In the crystal, molecules are linked by C—H...π and offset π–π interactions [intercentroid distances are 3.6421 (16) and 3.7813 (16) Å], forming a three-dimensional structure.

Keywords

• crystal structure
• terpyridine
• c—h...π interactions
• offset π–π interactions