Non-covalent polymerisation in the solid state: halogen–halogenvs. methyl–methyl interactions in the complexes of 2,4-di(2-pyridyl)-1,3,5-triazine ligands

Abstract

Fe(II), Co(II), Ni(II) and Cu(II) complexes based on the triazine ligand 2,4-di(2'-pyridyl)-6-(p-bromo-phenyl)-1,3,5-triazine have been synthesised and characterised. The electrochemical, magnetic and spectroscopic properties of the complexes have also been investigated, and the electron deficient triazine ligand has been shown to affect each of these properties. Further investigation of solid state structures of the ligand and its Fe(II), Co(II) and Cu(II) complexes has established that stabilising Br-Br interactions exist which link neighbouring molecules to form one-dimensional tapes. A slight modification of the ligand, i.e., using 2,4-di(2'-pyridyl)-6-(p-methylphenyl)-1,3,5-triazine, in which the phenyl substituent has changed from a bromine to a methyl group, eliminates the one-dimensional tape and gives rise to significant pi-stacking interactions in the solid state.

Achieving dynamic behaviour and thermal expansion in the organic solid state via co-crystallization

“…The volume of the single crystal decreased by 112 Å 3 , or approximately 4%. The differences in TE properties between 1 and 2 can be attributed to the presence of Br···Br interactions (3.64 Å), 23 as compared to the absence of halogen···halogen forces in 1 , that lie approximately along the crystallographic a -axis. The Br···Br forces remain intact upon cooling, which likely does not provide sufficient room for large twisting of the aromatic rings (Fig.…”

Tuning the Excited‐State Energy of the Organic Chromophore in Bichromophoric Systems Based on the RuII Complexes of Tridentate Ligands

“…[27,39] Short bromine-bromine contacts are observed in the solid state, and these interactions are smaller than the sum of the Van der Waals radii (3.48 ). In the absence of stabilizing p-stacking interactions, these contacts influence the cationic arrangements in the extended lattice.…”

4-Bromo-N-(4-bromophenyl)aniline

“…For related structures, see: Eriksson et al (2004); Plieth & Ruban (1961); Li et al (2010). For the van der Waals radius of Br and intermolecular BrÁ Á ÁBr contacts, see: Bondi (1964); Medlycott et al (2007). For a description of the pitch angle, see: Lim & Tanski (2007).…”