Supramolecular association and quantification of intermolecular interactions of 4′-functionalized 2,2′:6′,2-terpyridines: Experimental observation and theoretical studies

Three versatile 4'-substituted 2,2':6',2 ''-terpyridine compounds (1-3) having different substitutions (4-ethoxyphenyl, 4-methoxyphenyl and pyridyl) at 4'-position of the central pyridine ring have been synthesized and structurally characterized. Three representative crystal structures have been determined through single crystal X-ray diffraction analysis. X-ray crystallography revels that the structures are stabilized through C-H center dot center dot center dot pi at and pi-pi stacking interactions. In the solid-state, the supramolecular assemblies of the title compounds have been explored in detail. Compounds (1) and (3) exhibits both C-H center dot center dot center dot pi and pi-pi interactions in building supramolecular assemblies whereas compound (2) exhibit pi-pi interaction only. All the intermolecular interactions that are involved within the structures are quantified through Hirshfeld surface analyses. The weak noncovalent interactions that played significant role in building supramolecular assemblies are further characterized by Bader's theory of 'atoms-in-molecules' (AIM). Finally, the supramolecular networks are characterized by theoretical 'Noncovalent Interaction' (NCI) plot index. The supramolecular solid-state frameworks of three 4'-functionalized 2,2':6',2 ''-terpyridine derivatives have been quantified which are further characterized theoretically by the Bader's theory of 'atoms-inmolecules'(AIM) and 'noncovalent interaction' (NCI) plot index. (C) 2020 Published by Elsevier B.V.

Automated summary

Three versatile 4'-substituted 2,2':6',2''-terpyridine compounds with different substitutions have been synthesized and structurally characterized. The crystal structures show stabilization through C-H⋯π and π-π stacking interactions. Intermolecular interactions were quantified and characterized using Hirshfeld surface analyses and Bader's AIM theory.