Synthesis of rhenium-based M3L3L′-type metallacycle from benzimidazole and flexible tri(benzimidazole) ligands

► Neutral rhenium(I)-based mixed-ligands metallacycle. ► New bonding combinations i.e. Re(CO)3, ditopic donors, and tris(monodentate) donors. ► Capped metallacalix[3]arene-shaped supramolecule.