A supramolecular octahedron assembled by anion coordination and π‒π stacking interactions showing dual emission

Abstract

Inspired by the molecular self-assembly in biological systems, chemists design and synthesize artificial discrete structures to mimic the biological complexity and functionality. Most efforts focus on the metal-ligand driven self-assembly to produce complicated metal-organic cages, while discrete polyhedral self-assemblies constructed by weak intermolecular interactions such as hydrogen bonding and π‒π stacking interactions are extremely rare. Herein, we report a supramolecular octahedron {[CuLCl]⋅Cl⋅(fpn)}6 (1) (L = tris(2-naphthimidazolylmethyl) amine, fpn = 5-fluoroisophthalonitrile) in solid state arising from the self-assembly of [CuLCl]+, Cl‒, and fpn in CH3CN. In the octahedron, [CuLCl]+ cations occupying the vertexes of the octahedron are connected by Cl‒ and fpn on edges via hydrogen bonding and π‒π stacking interactions, respectively. Compound 1 in both solid and solution states shows dual emissions which originate from fpn and [CuLCl]+, respectively.