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

Alexander E Sedykh,Dirk G Kurth,Klaus Müller-Buschbaum

doi:10.1107/s2056989019015810

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 ortho-rhom-bic 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 mol-ecule, the whole mol-ecule 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, mol-ecules are linked by C-H⋯π and offset π-π inter-actions [inter-centroid distances are 3.6421 (16) and 3.7813 (16) Å], forming a three-dimensional structure.

Highlights

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
Molecules are linked by C—HÁ Á Á and offset – interactions [intercentroid distances are 3.6421 (16) and 3.7813 (16) A ], forming a three-dimensional structure
The molecule is located about a crystallographic centre of symmetry in the middle of the central benzene ring (C16–C18/C160–C180), the molecule has a higher symmetry than that observed for the orthorhombic polymorph, Form II (Fernandes et al, 2010), which has point group C1

Summary

Chemical context

1,4-Di([2,20:60,200-terpyridin]-40-yl)benzene has been used as a ligand in the formation of mononuclear complexes (Santoni et al, 2013; Laramee-Milette & Hanan, 2017), binuclear complexes (Santoni et al, 2013; Schmittel et al.,2006; Maekawa et al, 2004), tetranuclear complexes (Schmittel et al, 2005), one-dimensional coordination polymers (Koo et al, 2003), two-dimensional coordination polymers (Bulut et al, 2015; Jones et al (2010), and numerous metallo-supramolecular polymers (without reported crystal structures), see for example: Vaduvescu & Potvin, 2004; Nishimori et al, 2007; Han et al, 2008; Schwarz et al, 2010; Ding et al, 2012; Muronoi et al, 2013; Szczerba et al, 2014; Munzert et al, 2016; Meded et al, 2017; Bera et al, 2018. Title compound yielded only nine hits (see supporting information), which included the report on the structure of the orthorhombic polymorph, Form II, by Fernandes et al (2010)

Structural commentary

Supramolecular features

Synthesis and crystallization